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32 results

memcontrol.c

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  • x86.c 246.20 KiB
    /*
     * Kernel-based Virtual Machine driver for Linux
     *
     * derived from drivers/kvm/kvm_main.c
     *
     * Copyright (C) 2006 Qumranet, Inc.
     * Copyright (C) 2008 Qumranet, Inc.
     * Copyright IBM Corporation, 2008
     * Copyright 2010 Red Hat, Inc. and/or its affiliates.
     *
     * Authors:
     *   Avi Kivity   <avi@qumranet.com>
     *   Yaniv Kamay  <yaniv@qumranet.com>
     *   Amit Shah    <amit.shah@qumranet.com>
     *   Ben-Ami Yassour <benami@il.ibm.com>
     *
     * This work is licensed under the terms of the GNU GPL, version 2.  See
     * the COPYING file in the top-level directory.
     *
     */
    
    #include <linux/kvm_host.h>
    #include "irq.h"
    #include "mmu.h"
    #include "i8254.h"
    #include "tss.h"
    #include "kvm_cache_regs.h"
    #include "x86.h"
    #include "cpuid.h"
    #include "pmu.h"
    #include "hyperv.h"
    
    #include <linux/clocksource.h>
    #include <linux/interrupt.h>
    #include <linux/kvm.h>
    #include <linux/fs.h>
    #include <linux/vmalloc.h>
    #include <linux/export.h>
    #include <linux/moduleparam.h>
    #include <linux/mman.h>
    #include <linux/highmem.h>
    #include <linux/iommu.h>
    #include <linux/intel-iommu.h>
    #include <linux/cpufreq.h>
    #include <linux/user-return-notifier.h>
    #include <linux/srcu.h>
    #include <linux/slab.h>
    #include <linux/perf_event.h>
    #include <linux/uaccess.h>
    #include <linux/hash.h>
    #include <linux/pci.h>
    #include <linux/timekeeper_internal.h>
    #include <linux/pvclock_gtod.h>
    #include <linux/kvm_irqfd.h>
    #include <linux/irqbypass.h>
    #include <linux/sched/stat.h>
    #include <linux/mem_encrypt.h>
    
    #include <trace/events/kvm.h>
    
    #include <asm/debugreg.h>
    #include <asm/msr.h>
    #include <asm/desc.h>
    #include <asm/mce.h>
    #include <linux/kernel_stat.h>
    #include <asm/fpu/internal.h> /* Ugh! */
    #include <asm/pvclock.h>
    #include <asm/div64.h>
    #include <asm/irq_remapping.h>
    #include <asm/mshyperv.h>
    #include <asm/hypervisor.h>
    
    #define CREATE_TRACE_POINTS
    #include "trace.h"
    
    #define MAX_IO_MSRS 256
    #define KVM_MAX_MCE_BANKS 32
    u64 __read_mostly kvm_mce_cap_supported = MCG_CTL_P | MCG_SER_P;
    EXPORT_SYMBOL_GPL(kvm_mce_cap_supported);
    
    #define emul_to_vcpu(ctxt) \
    	container_of(ctxt, struct kvm_vcpu, arch.emulate_ctxt)
    
    /* EFER defaults:
     * - enable syscall per default because its emulated by KVM
     * - enable LME and LMA per default on 64 bit KVM
     */
    #ifdef CONFIG_X86_64
    static
    u64 __read_mostly efer_reserved_bits = ~((u64)(EFER_SCE | EFER_LME | EFER_LMA));
    #else
    static u64 __read_mostly efer_reserved_bits = ~((u64)EFER_SCE);
    #endif
    
    #define VM_STAT(x) offsetof(struct kvm, stat.x), KVM_STAT_VM
    #define VCPU_STAT(x) offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU
    
    #define KVM_X2APIC_API_VALID_FLAGS (KVM_X2APIC_API_USE_32BIT_IDS | \
                                        KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK)
    
    static void update_cr8_intercept(struct kvm_vcpu *vcpu);
    static void process_nmi(struct kvm_vcpu *vcpu);
    static void enter_smm(struct kvm_vcpu *vcpu);
    static void __kvm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags);
    static void store_regs(struct kvm_vcpu *vcpu);
    static int sync_regs(struct kvm_vcpu *vcpu);
    
    struct kvm_x86_ops *kvm_x86_ops __read_mostly;
    EXPORT_SYMBOL_GPL(kvm_x86_ops);
    
    static bool __read_mostly ignore_msrs = 0;
    module_param(ignore_msrs, bool, S_IRUGO | S_IWUSR);
    
    static bool __read_mostly report_ignored_msrs = true;
    module_param(report_ignored_msrs, bool, S_IRUGO | S_IWUSR);
    
    unsigned int min_timer_period_us = 200;
    module_param(min_timer_period_us, uint, S_IRUGO | S_IWUSR);
    
    static bool __read_mostly kvmclock_periodic_sync = true;
    module_param(kvmclock_periodic_sync, bool, S_IRUGO);
    
    bool __read_mostly kvm_has_tsc_control;
    EXPORT_SYMBOL_GPL(kvm_has_tsc_control);
    u32  __read_mostly kvm_max_guest_tsc_khz;
    EXPORT_SYMBOL_GPL(kvm_max_guest_tsc_khz);
    u8   __read_mostly kvm_tsc_scaling_ratio_frac_bits;
    EXPORT_SYMBOL_GPL(kvm_tsc_scaling_ratio_frac_bits);
    u64  __read_mostly kvm_max_tsc_scaling_ratio;
    EXPORT_SYMBOL_GPL(kvm_max_tsc_scaling_ratio);
    u64 __read_mostly kvm_default_tsc_scaling_ratio;
    EXPORT_SYMBOL_GPL(kvm_default_tsc_scaling_ratio);
    
    /* tsc tolerance in parts per million - default to 1/2 of the NTP threshold */
    static u32 __read_mostly tsc_tolerance_ppm = 250;
    module_param(tsc_tolerance_ppm, uint, S_IRUGO | S_IWUSR);
    
    /* lapic timer advance (tscdeadline mode only) in nanoseconds */
    unsigned int __read_mostly lapic_timer_advance_ns = 0;
    module_param(lapic_timer_advance_ns, uint, S_IRUGO | S_IWUSR);
    EXPORT_SYMBOL_GPL(lapic_timer_advance_ns);
    
    static bool __read_mostly vector_hashing = true;
    module_param(vector_hashing, bool, S_IRUGO);
    
    bool __read_mostly enable_vmware_backdoor = false;
    module_param(enable_vmware_backdoor, bool, S_IRUGO);
    EXPORT_SYMBOL_GPL(enable_vmware_backdoor);
    
    static bool __read_mostly force_emulation_prefix = false;
    module_param(force_emulation_prefix, bool, S_IRUGO);
    
    #define KVM_NR_SHARED_MSRS 16
    
    struct kvm_shared_msrs_global {
    	int nr;
    	u32 msrs[KVM_NR_SHARED_MSRS];
    };
    
    struct kvm_shared_msrs {
    	struct user_return_notifier urn;
    	bool registered;
    	struct kvm_shared_msr_values {
    		u64 host;
    		u64 curr;
    	} values[KVM_NR_SHARED_MSRS];
    };
    
    static struct kvm_shared_msrs_global __read_mostly shared_msrs_global;
    static struct kvm_shared_msrs __percpu *shared_msrs;
    
    struct kvm_stats_debugfs_item debugfs_entries[] = {
    	{ "pf_fixed", VCPU_STAT(pf_fixed) },
    	{ "pf_guest", VCPU_STAT(pf_guest) },
    	{ "tlb_flush", VCPU_STAT(tlb_flush) },
    	{ "invlpg", VCPU_STAT(invlpg) },
    	{ "exits", VCPU_STAT(exits) },
    	{ "io_exits", VCPU_STAT(io_exits) },
    	{ "mmio_exits", VCPU_STAT(mmio_exits) },
    	{ "signal_exits", VCPU_STAT(signal_exits) },
    	{ "irq_window", VCPU_STAT(irq_window_exits) },
    	{ "nmi_window", VCPU_STAT(nmi_window_exits) },
    	{ "halt_exits", VCPU_STAT(halt_exits) },
    	{ "halt_successful_poll", VCPU_STAT(halt_successful_poll) },
    	{ "halt_attempted_poll", VCPU_STAT(halt_attempted_poll) },
    	{ "halt_poll_invalid", VCPU_STAT(halt_poll_invalid) },
    	{ "halt_wakeup", VCPU_STAT(halt_wakeup) },
    	{ "hypercalls", VCPU_STAT(hypercalls) },
    	{ "request_irq", VCPU_STAT(request_irq_exits) },
    	{ "irq_exits", VCPU_STAT(irq_exits) },
    	{ "host_state_reload", VCPU_STAT(host_state_reload) },
    	{ "fpu_reload", VCPU_STAT(fpu_reload) },
    	{ "insn_emulation", VCPU_STAT(insn_emulation) },
    	{ "insn_emulation_fail", VCPU_STAT(insn_emulation_fail) },
    	{ "irq_injections", VCPU_STAT(irq_injections) },
    	{ "nmi_injections", VCPU_STAT(nmi_injections) },
    	{ "req_event", VCPU_STAT(req_event) },
    	{ "l1d_flush", VCPU_STAT(l1d_flush) },
    	{ "mmu_shadow_zapped", VM_STAT(mmu_shadow_zapped) },
    	{ "mmu_pte_write", VM_STAT(mmu_pte_write) },
    	{ "mmu_pte_updated", VM_STAT(mmu_pte_updated) },
    	{ "mmu_pde_zapped", VM_STAT(mmu_pde_zapped) },
    	{ "mmu_flooded", VM_STAT(mmu_flooded) },
    	{ "mmu_recycled", VM_STAT(mmu_recycled) },
    	{ "mmu_cache_miss", VM_STAT(mmu_cache_miss) },
    	{ "mmu_unsync", VM_STAT(mmu_unsync) },
    	{ "remote_tlb_flush", VM_STAT(remote_tlb_flush) },
    	{ "largepages", VM_STAT(lpages) },
    	{ "max_mmu_page_hash_collisions",
    		VM_STAT(max_mmu_page_hash_collisions) },
    	{ NULL }
    };
    
    u64 __read_mostly host_xcr0;
    
    static int emulator_fix_hypercall(struct x86_emulate_ctxt *ctxt);
    
    static inline void kvm_async_pf_hash_reset(struct kvm_vcpu *vcpu)
    {
    	int i;
    	for (i = 0; i < roundup_pow_of_two(ASYNC_PF_PER_VCPU); i++)
    		vcpu->arch.apf.gfns[i] = ~0;
    }
    
    static void kvm_on_user_return(struct user_return_notifier *urn)
    {
    	unsigned slot;
    	struct kvm_shared_msrs *locals
    		= container_of(urn, struct kvm_shared_msrs, urn);
    	struct kvm_shared_msr_values *values;
    	unsigned long flags;
    
    	/*
    	 * Disabling irqs at this point since the following code could be
    	 * interrupted and executed through kvm_arch_hardware_disable()
    	 */
    	local_irq_save(flags);
    	if (locals->registered) {
    		locals->registered = false;
    		user_return_notifier_unregister(urn);
    	}
    	local_irq_restore(flags);
    	for (slot = 0; slot < shared_msrs_global.nr; ++slot) {
    		values = &locals->values[slot];
    		if (values->host != values->curr) {
    			wrmsrl(shared_msrs_global.msrs[slot], values->host);
    			values->curr = values->host;
    		}
    	}
    }
    
    static void shared_msr_update(unsigned slot, u32 msr)
    {
    	u64 value;
    	unsigned int cpu = smp_processor_id();
    	struct kvm_shared_msrs *smsr = per_cpu_ptr(shared_msrs, cpu);
    
    	/* only read, and nobody should modify it at this time,
    	 * so don't need lock */
    	if (slot >= shared_msrs_global.nr) {
    		printk(KERN_ERR "kvm: invalid MSR slot!");
    		return;
    	}
    	rdmsrl_safe(msr, &value);
    	smsr->values[slot].host = value;
    	smsr->values[slot].curr = value;
    }
    
    void kvm_define_shared_msr(unsigned slot, u32 msr)
    {
    	BUG_ON(slot >= KVM_NR_SHARED_MSRS);
    	shared_msrs_global.msrs[slot] = msr;
    	if (slot >= shared_msrs_global.nr)
    		shared_msrs_global.nr = slot + 1;
    }
    EXPORT_SYMBOL_GPL(kvm_define_shared_msr);
    
    static void kvm_shared_msr_cpu_online(void)
    {
    	unsigned i;
    
    	for (i = 0; i < shared_msrs_global.nr; ++i)
    		shared_msr_update(i, shared_msrs_global.msrs[i]);
    }
    
    int kvm_set_shared_msr(unsigned slot, u64 value, u64 mask)
    {
    	unsigned int cpu = smp_processor_id();
    	struct kvm_shared_msrs *smsr = per_cpu_ptr(shared_msrs, cpu);
    	int err;
    
    	if (((value ^ smsr->values[slot].curr) & mask) == 0)
    		return 0;
    	smsr->values[slot].curr = value;
    	err = wrmsrl_safe(shared_msrs_global.msrs[slot], value);
    	if (err)
    		return 1;
    
    	if (!smsr->registered) {
    		smsr->urn.on_user_return = kvm_on_user_return;
    		user_return_notifier_register(&smsr->urn);
    		smsr->registered = true;
    	}
    	return 0;
    }
    EXPORT_SYMBOL_GPL(kvm_set_shared_msr);
    
    static void drop_user_return_notifiers(void)
    {
    	unsigned int cpu = smp_processor_id();
    	struct kvm_shared_msrs *smsr = per_cpu_ptr(shared_msrs, cpu);
    
    	if (smsr->registered)
    		kvm_on_user_return(&smsr->urn);
    }
    
    u64 kvm_get_apic_base(struct kvm_vcpu *vcpu)
    {
    	return vcpu->arch.apic_base;
    }
    EXPORT_SYMBOL_GPL(kvm_get_apic_base);
    
    enum lapic_mode kvm_get_apic_mode(struct kvm_vcpu *vcpu)
    {
    	return kvm_apic_mode(kvm_get_apic_base(vcpu));
    }
    EXPORT_SYMBOL_GPL(kvm_get_apic_mode);
    
    int kvm_set_apic_base(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
    {
    	enum lapic_mode old_mode = kvm_get_apic_mode(vcpu);
    	enum lapic_mode new_mode = kvm_apic_mode(msr_info->data);
    	u64 reserved_bits = ((~0ULL) << cpuid_maxphyaddr(vcpu)) | 0x2ff |
    		(guest_cpuid_has(vcpu, X86_FEATURE_X2APIC) ? 0 : X2APIC_ENABLE);
    
    	if ((msr_info->data & reserved_bits) != 0 || new_mode == LAPIC_MODE_INVALID)
    		return 1;
    	if (!msr_info->host_initiated) {
    		if (old_mode == LAPIC_MODE_X2APIC && new_mode == LAPIC_MODE_XAPIC)
    			return 1;
    		if (old_mode == LAPIC_MODE_DISABLED && new_mode == LAPIC_MODE_X2APIC)
    			return 1;
    	}
    
    	kvm_lapic_set_base(vcpu, msr_info->data);
    	return 0;
    }
    EXPORT_SYMBOL_GPL(kvm_set_apic_base);
    
    asmlinkage __visible void kvm_spurious_fault(void)
    {
    	/* Fault while not rebooting.  We want the trace. */
    	BUG();
    }
    EXPORT_SYMBOL_GPL(kvm_spurious_fault);
    
    #define EXCPT_BENIGN		0
    #define EXCPT_CONTRIBUTORY	1
    #define EXCPT_PF		2
    
    static int exception_class(int vector)
    {
    	switch (vector) {
    	case PF_VECTOR:
    		return EXCPT_PF;
    	case DE_VECTOR:
    	case TS_VECTOR:
    	case NP_VECTOR:
    	case SS_VECTOR:
    	case GP_VECTOR:
    		return EXCPT_CONTRIBUTORY;
    	default:
    		break;
    	}
    	return EXCPT_BENIGN;
    }
    
    #define EXCPT_FAULT		0
    #define EXCPT_TRAP		1
    #define EXCPT_ABORT		2
    #define EXCPT_INTERRUPT		3
    
    static int exception_type(int vector)
    {
    	unsigned int mask;
    
    	if (WARN_ON(vector > 31 || vector == NMI_VECTOR))
    		return EXCPT_INTERRUPT;
    
    	mask = 1 << vector;
    
    	/* #DB is trap, as instruction watchpoints are handled elsewhere */
    	if (mask & ((1 << DB_VECTOR) | (1 << BP_VECTOR) | (1 << OF_VECTOR)))
    		return EXCPT_TRAP;
    
    	if (mask & ((1 << DF_VECTOR) | (1 << MC_VECTOR)))
    		return EXCPT_ABORT;
    
    	/* Reserved exceptions will result in fault */
    	return EXCPT_FAULT;
    }
    
    static void kvm_multiple_exception(struct kvm_vcpu *vcpu,
    		unsigned nr, bool has_error, u32 error_code,
    		bool reinject)
    {
    	u32 prev_nr;
    	int class1, class2;
    
    	kvm_make_request(KVM_REQ_EVENT, vcpu);
    
    	if (!vcpu->arch.exception.pending && !vcpu->arch.exception.injected) {
    	queue:
    		if (has_error && !is_protmode(vcpu))
    			has_error = false;
    		if (reinject) {
    			/*
    			 * On vmentry, vcpu->arch.exception.pending is only
    			 * true if an event injection was blocked by
    			 * nested_run_pending.  In that case, however,
    			 * vcpu_enter_guest requests an immediate exit,
    			 * and the guest shouldn't proceed far enough to
    			 * need reinjection.
    			 */
    			WARN_ON_ONCE(vcpu->arch.exception.pending);
    			vcpu->arch.exception.injected = true;
    		} else {
    			vcpu->arch.exception.pending = true;
    			vcpu->arch.exception.injected = false;
    		}
    		vcpu->arch.exception.has_error_code = has_error;
    		vcpu->arch.exception.nr = nr;
    		vcpu->arch.exception.error_code = error_code;
    		return;
    	}
    
    	/* to check exception */
    	prev_nr = vcpu->arch.exception.nr;
    	if (prev_nr == DF_VECTOR) {
    		/* triple fault -> shutdown */
    		kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
    		return;
    	}
    	class1 = exception_class(prev_nr);
    	class2 = exception_class(nr);
    	if ((class1 == EXCPT_CONTRIBUTORY && class2 == EXCPT_CONTRIBUTORY)
    		|| (class1 == EXCPT_PF && class2 != EXCPT_BENIGN)) {
    		/*
    		 * Generate double fault per SDM Table 5-5.  Set
    		 * exception.pending = true so that the double fault
    		 * can trigger a nested vmexit.
    		 */
    		vcpu->arch.exception.pending = true;
    		vcpu->arch.exception.injected = false;
    		vcpu->arch.exception.has_error_code = true;
    		vcpu->arch.exception.nr = DF_VECTOR;
    		vcpu->arch.exception.error_code = 0;
    	} else
    		/* replace previous exception with a new one in a hope
    		   that instruction re-execution will regenerate lost
    		   exception */
    		goto queue;
    }
    
    void kvm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr)
    {
    	kvm_multiple_exception(vcpu, nr, false, 0, false);
    }
    EXPORT_SYMBOL_GPL(kvm_queue_exception);
    
    void kvm_requeue_exception(struct kvm_vcpu *vcpu, unsigned nr)
    {
    	kvm_multiple_exception(vcpu, nr, false, 0, true);
    }
    EXPORT_SYMBOL_GPL(kvm_requeue_exception);
    
    int kvm_complete_insn_gp(struct kvm_vcpu *vcpu, int err)
    {
    	if (err)
    		kvm_inject_gp(vcpu, 0);
    	else
    		return kvm_skip_emulated_instruction(vcpu);
    
    	return 1;
    }
    EXPORT_SYMBOL_GPL(kvm_complete_insn_gp);
    
    void kvm_inject_page_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault)
    {
    	++vcpu->stat.pf_guest;
    	vcpu->arch.exception.nested_apf =
    		is_guest_mode(vcpu) && fault->async_page_fault;
    	if (vcpu->arch.exception.nested_apf)
    		vcpu->arch.apf.nested_apf_token = fault->address;
    	else
    		vcpu->arch.cr2 = fault->address;
    	kvm_queue_exception_e(vcpu, PF_VECTOR, fault->error_code);
    }
    EXPORT_SYMBOL_GPL(kvm_inject_page_fault);
    
    static bool kvm_propagate_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault)
    {
    	if (mmu_is_nested(vcpu) && !fault->nested_page_fault)
    		vcpu->arch.nested_mmu.inject_page_fault(vcpu, fault);
    	else
    		vcpu->arch.mmu.inject_page_fault(vcpu, fault);
    
    	return fault->nested_page_fault;
    }
    
    void kvm_inject_nmi(struct kvm_vcpu *vcpu)
    {
    	atomic_inc(&vcpu->arch.nmi_queued);
    	kvm_make_request(KVM_REQ_NMI, vcpu);
    }
    EXPORT_SYMBOL_GPL(kvm_inject_nmi);
    
    void kvm_queue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code)
    {
    	kvm_multiple_exception(vcpu, nr, true, error_code, false);
    }
    EXPORT_SYMBOL_GPL(kvm_queue_exception_e);
    
    void kvm_requeue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code)
    {
    	kvm_multiple_exception(vcpu, nr, true, error_code, true);
    }
    EXPORT_SYMBOL_GPL(kvm_requeue_exception_e);
    
    /*
     * Checks if cpl <= required_cpl; if true, return true.  Otherwise queue
     * a #GP and return false.
     */
    bool kvm_require_cpl(struct kvm_vcpu *vcpu, int required_cpl)
    {
    	if (kvm_x86_ops->get_cpl(vcpu) <= required_cpl)
    		return true;
    	kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
    	return false;
    }
    EXPORT_SYMBOL_GPL(kvm_require_cpl);
    
    bool kvm_require_dr(struct kvm_vcpu *vcpu, int dr)
    {
    	if ((dr != 4 && dr != 5) || !kvm_read_cr4_bits(vcpu, X86_CR4_DE))
    		return true;
    
    	kvm_queue_exception(vcpu, UD_VECTOR);
    	return false;
    }
    EXPORT_SYMBOL_GPL(kvm_require_dr);
    
    /*
     * This function will be used to read from the physical memory of the currently
     * running guest. The difference to kvm_vcpu_read_guest_page is that this function
     * can read from guest physical or from the guest's guest physical memory.
     */
    int kvm_read_guest_page_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
    			    gfn_t ngfn, void *data, int offset, int len,
    			    u32 access)
    {
    	struct x86_exception exception;
    	gfn_t real_gfn;
    	gpa_t ngpa;
    
    	ngpa     = gfn_to_gpa(ngfn);
    	real_gfn = mmu->translate_gpa(vcpu, ngpa, access, &exception);
    	if (real_gfn == UNMAPPED_GVA)
    		return -EFAULT;
    
    	real_gfn = gpa_to_gfn(real_gfn);
    
    	return kvm_vcpu_read_guest_page(vcpu, real_gfn, data, offset, len);
    }
    EXPORT_SYMBOL_GPL(kvm_read_guest_page_mmu);
    
    static int kvm_read_nested_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn,
    			       void *data, int offset, int len, u32 access)
    {
    	return kvm_read_guest_page_mmu(vcpu, vcpu->arch.walk_mmu, gfn,
    				       data, offset, len, access);
    }
    
    /*
     * Load the pae pdptrs.  Return true is they are all valid.
     */
    int load_pdptrs(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, unsigned long cr3)
    {
    	gfn_t pdpt_gfn = cr3 >> PAGE_SHIFT;
    	unsigned offset = ((cr3 & (PAGE_SIZE-1)) >> 5) << 2;
    	int i;
    	int ret;
    	u64 pdpte[ARRAY_SIZE(mmu->pdptrs)];
    
    	ret = kvm_read_guest_page_mmu(vcpu, mmu, pdpt_gfn, pdpte,
    				      offset * sizeof(u64), sizeof(pdpte),
    				      PFERR_USER_MASK|PFERR_WRITE_MASK);
    	if (ret < 0) {
    		ret = 0;
    		goto out;
    	}
    	for (i = 0; i < ARRAY_SIZE(pdpte); ++i) {
    		if ((pdpte[i] & PT_PRESENT_MASK) &&
    		    (pdpte[i] &
    		     vcpu->arch.mmu.guest_rsvd_check.rsvd_bits_mask[0][2])) {
    			ret = 0;
    			goto out;
    		}
    	}
    	ret = 1;
    
    	memcpy(mmu->pdptrs, pdpte, sizeof(mmu->pdptrs));
    	__set_bit(VCPU_EXREG_PDPTR,
    		  (unsigned long *)&vcpu->arch.regs_avail);
    	__set_bit(VCPU_EXREG_PDPTR,
    		  (unsigned long *)&vcpu->arch.regs_dirty);
    out:
    
    	return ret;
    }
    EXPORT_SYMBOL_GPL(load_pdptrs);
    
    bool pdptrs_changed(struct kvm_vcpu *vcpu)
    {
    	u64 pdpte[ARRAY_SIZE(vcpu->arch.walk_mmu->pdptrs)];
    	bool changed = true;
    	int offset;
    	gfn_t gfn;
    	int r;
    
    	if (is_long_mode(vcpu) || !is_pae(vcpu) || !is_paging(vcpu))
    		return false;
    
    	if (!test_bit(VCPU_EXREG_PDPTR,
    		      (unsigned long *)&vcpu->arch.regs_avail))
    		return true;
    
    	gfn = (kvm_read_cr3(vcpu) & 0xffffffe0ul) >> PAGE_SHIFT;
    	offset = (kvm_read_cr3(vcpu) & 0xffffffe0ul) & (PAGE_SIZE - 1);
    	r = kvm_read_nested_guest_page(vcpu, gfn, pdpte, offset, sizeof(pdpte),
    				       PFERR_USER_MASK | PFERR_WRITE_MASK);
    	if (r < 0)
    		goto out;
    	changed = memcmp(pdpte, vcpu->arch.walk_mmu->pdptrs, sizeof(pdpte)) != 0;
    out:
    
    	return changed;
    }
    EXPORT_SYMBOL_GPL(pdptrs_changed);
    
    int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
    {
    	unsigned long old_cr0 = kvm_read_cr0(vcpu);
    	unsigned long update_bits = X86_CR0_PG | X86_CR0_WP;
    
    	cr0 |= X86_CR0_ET;
    
    #ifdef CONFIG_X86_64
    	if (cr0 & 0xffffffff00000000UL)
    		return 1;
    #endif
    
    	cr0 &= ~CR0_RESERVED_BITS;
    
    	if ((cr0 & X86_CR0_NW) && !(cr0 & X86_CR0_CD))
    		return 1;
    
    	if ((cr0 & X86_CR0_PG) && !(cr0 & X86_CR0_PE))
    		return 1;
    
    	if (!is_paging(vcpu) && (cr0 & X86_CR0_PG)) {
    #ifdef CONFIG_X86_64
    		if ((vcpu->arch.efer & EFER_LME)) {
    			int cs_db, cs_l;
    
    			if (!is_pae(vcpu))
    				return 1;
    			kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);
    			if (cs_l)
    				return 1;
    		} else
    #endif
    		if (is_pae(vcpu) && !load_pdptrs(vcpu, vcpu->arch.walk_mmu,
    						 kvm_read_cr3(vcpu)))
    			return 1;
    	}
    
    	if (!(cr0 & X86_CR0_PG) && kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE))
    		return 1;
    
    	kvm_x86_ops->set_cr0(vcpu, cr0);
    
    	if ((cr0 ^ old_cr0) & X86_CR0_PG) {
    		kvm_clear_async_pf_completion_queue(vcpu);
    		kvm_async_pf_hash_reset(vcpu);
    	}
    
    	if ((cr0 ^ old_cr0) & update_bits)
    		kvm_mmu_reset_context(vcpu);
    
    	if (((cr0 ^ old_cr0) & X86_CR0_CD) &&
    	    kvm_arch_has_noncoherent_dma(vcpu->kvm) &&
    	    !kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_CD_NW_CLEARED))
    		kvm_zap_gfn_range(vcpu->kvm, 0, ~0ULL);
    
    	return 0;
    }
    EXPORT_SYMBOL_GPL(kvm_set_cr0);
    
    void kvm_lmsw(struct kvm_vcpu *vcpu, unsigned long msw)
    {
    	(void)kvm_set_cr0(vcpu, kvm_read_cr0_bits(vcpu, ~0x0eul) | (msw & 0x0f));
    }
    EXPORT_SYMBOL_GPL(kvm_lmsw);
    
    static void kvm_load_guest_xcr0(struct kvm_vcpu *vcpu)
    {
    	if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE) &&
    			!vcpu->guest_xcr0_loaded) {
    		/* kvm_set_xcr() also depends on this */
    		if (vcpu->arch.xcr0 != host_xcr0)
    			xsetbv(XCR_XFEATURE_ENABLED_MASK, vcpu->arch.xcr0);
    		vcpu->guest_xcr0_loaded = 1;
    	}
    }
    
    static void kvm_put_guest_xcr0(struct kvm_vcpu *vcpu)
    {
    	if (vcpu->guest_xcr0_loaded) {
    		if (vcpu->arch.xcr0 != host_xcr0)
    			xsetbv(XCR_XFEATURE_ENABLED_MASK, host_xcr0);
    		vcpu->guest_xcr0_loaded = 0;
    	}
    }
    
    static int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
    {
    	u64 xcr0 = xcr;
    	u64 old_xcr0 = vcpu->arch.xcr0;
    	u64 valid_bits;
    
    	/* Only support XCR_XFEATURE_ENABLED_MASK(xcr0) now  */
    	if (index != XCR_XFEATURE_ENABLED_MASK)
    		return 1;
    	if (!(xcr0 & XFEATURE_MASK_FP))
    		return 1;
    	if ((xcr0 & XFEATURE_MASK_YMM) && !(xcr0 & XFEATURE_MASK_SSE))
    		return 1;
    
    	/*
    	 * Do not allow the guest to set bits that we do not support
    	 * saving.  However, xcr0 bit 0 is always set, even if the
    	 * emulated CPU does not support XSAVE (see fx_init).
    	 */
    	valid_bits = vcpu->arch.guest_supported_xcr0 | XFEATURE_MASK_FP;
    	if (xcr0 & ~valid_bits)
    		return 1;
    
    	if ((!(xcr0 & XFEATURE_MASK_BNDREGS)) !=
    	    (!(xcr0 & XFEATURE_MASK_BNDCSR)))
    		return 1;
    
    	if (xcr0 & XFEATURE_MASK_AVX512) {
    		if (!(xcr0 & XFEATURE_MASK_YMM))
    			return 1;
    		if ((xcr0 & XFEATURE_MASK_AVX512) != XFEATURE_MASK_AVX512)
    			return 1;
    	}
    	vcpu->arch.xcr0 = xcr0;
    
    	if ((xcr0 ^ old_xcr0) & XFEATURE_MASK_EXTEND)
    		kvm_update_cpuid(vcpu);
    	return 0;
    }
    
    int kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
    {
    	if (kvm_x86_ops->get_cpl(vcpu) != 0 ||
    	    __kvm_set_xcr(vcpu, index, xcr)) {
    		kvm_inject_gp(vcpu, 0);
    		return 1;
    	}
    	return 0;
    }
    EXPORT_SYMBOL_GPL(kvm_set_xcr);
    
    int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
    {
    	unsigned long old_cr4 = kvm_read_cr4(vcpu);
    	unsigned long pdptr_bits = X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PAE |
    				   X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_PKE;
    
    	if (cr4 & CR4_RESERVED_BITS)
    		return 1;
    
    	if (!guest_cpuid_has(vcpu, X86_FEATURE_XSAVE) && (cr4 & X86_CR4_OSXSAVE))
    		return 1;
    
    	if (!guest_cpuid_has(vcpu, X86_FEATURE_SMEP) && (cr4 & X86_CR4_SMEP))
    		return 1;
    
    	if (!guest_cpuid_has(vcpu, X86_FEATURE_SMAP) && (cr4 & X86_CR4_SMAP))
    		return 1;
    
    	if (!guest_cpuid_has(vcpu, X86_FEATURE_FSGSBASE) && (cr4 & X86_CR4_FSGSBASE))
    		return 1;
    
    	if (!guest_cpuid_has(vcpu, X86_FEATURE_PKU) && (cr4 & X86_CR4_PKE))
    		return 1;
    
    	if (!guest_cpuid_has(vcpu, X86_FEATURE_LA57) && (cr4 & X86_CR4_LA57))
    		return 1;
    
    	if (!guest_cpuid_has(vcpu, X86_FEATURE_UMIP) && (cr4 & X86_CR4_UMIP))
    		return 1;
    
    	if (is_long_mode(vcpu)) {
    		if (!(cr4 & X86_CR4_PAE))
    			return 1;
    	} else if (is_paging(vcpu) && (cr4 & X86_CR4_PAE)
    		   && ((cr4 ^ old_cr4) & pdptr_bits)
    		   && !load_pdptrs(vcpu, vcpu->arch.walk_mmu,
    				   kvm_read_cr3(vcpu)))
    		return 1;
    
    	if ((cr4 & X86_CR4_PCIDE) && !(old_cr4 & X86_CR4_PCIDE)) {
    		if (!guest_cpuid_has(vcpu, X86_FEATURE_PCID))
    			return 1;
    
    		/* PCID can not be enabled when cr3[11:0]!=000H or EFER.LMA=0 */
    		if ((kvm_read_cr3(vcpu) & X86_CR3_PCID_MASK) || !is_long_mode(vcpu))
    			return 1;
    	}
    
    	if (kvm_x86_ops->set_cr4(vcpu, cr4))
    		return 1;
    
    	if (((cr4 ^ old_cr4) & pdptr_bits) ||
    	    (!(cr4 & X86_CR4_PCIDE) && (old_cr4 & X86_CR4_PCIDE)))
    		kvm_mmu_reset_context(vcpu);
    
    	if ((cr4 ^ old_cr4) & (X86_CR4_OSXSAVE | X86_CR4_PKE))
    		kvm_update_cpuid(vcpu);
    
    	return 0;
    }
    EXPORT_SYMBOL_GPL(kvm_set_cr4);
    
    int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
    {
    	bool skip_tlb_flush = false;
    #ifdef CONFIG_X86_64
    	bool pcid_enabled = kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE);
    
    	if (pcid_enabled) {
    		skip_tlb_flush = cr3 & X86_CR3_PCID_NOFLUSH;
    		cr3 &= ~X86_CR3_PCID_NOFLUSH;
    	}
    #endif
    
    	if (cr3 == kvm_read_cr3(vcpu) && !pdptrs_changed(vcpu)) {
    		if (!skip_tlb_flush) {
    			kvm_mmu_sync_roots(vcpu);
    			kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
    		}
    		return 0;
    	}
    
    	if (is_long_mode(vcpu) &&
    	    (cr3 & rsvd_bits(cpuid_maxphyaddr(vcpu), 63)))
    		return 1;
    	else if (is_pae(vcpu) && is_paging(vcpu) &&
    		   !load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3))
    		return 1;
    
    	kvm_mmu_new_cr3(vcpu, cr3, skip_tlb_flush);
    	vcpu->arch.cr3 = cr3;
    	__set_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail);
    
    	return 0;
    }
    EXPORT_SYMBOL_GPL(kvm_set_cr3);
    
    int kvm_set_cr8(struct kvm_vcpu *vcpu, unsigned long cr8)
    {
    	if (cr8 & CR8_RESERVED_BITS)
    		return 1;
    	if (lapic_in_kernel(vcpu))
    		kvm_lapic_set_tpr(vcpu, cr8);
    	else
    		vcpu->arch.cr8 = cr8;
    	return 0;
    }
    EXPORT_SYMBOL_GPL(kvm_set_cr8);
    
    unsigned long kvm_get_cr8(struct kvm_vcpu *vcpu)
    {
    	if (lapic_in_kernel(vcpu))
    		return kvm_lapic_get_cr8(vcpu);
    	else
    		return vcpu->arch.cr8;
    }
    EXPORT_SYMBOL_GPL(kvm_get_cr8);
    
    static void kvm_update_dr0123(struct kvm_vcpu *vcpu)
    {
    	int i;
    
    	if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)) {
    		for (i = 0; i < KVM_NR_DB_REGS; i++)
    			vcpu->arch.eff_db[i] = vcpu->arch.db[i];
    		vcpu->arch.switch_db_regs |= KVM_DEBUGREG_RELOAD;
    	}
    }
    
    static void kvm_update_dr6(struct kvm_vcpu *vcpu)
    {
    	if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP))
    		kvm_x86_ops->set_dr6(vcpu, vcpu->arch.dr6);
    }
    
    static void kvm_update_dr7(struct kvm_vcpu *vcpu)
    {
    	unsigned long dr7;
    
    	if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
    		dr7 = vcpu->arch.guest_debug_dr7;
    	else
    		dr7 = vcpu->arch.dr7;
    	kvm_x86_ops->set_dr7(vcpu, dr7);
    	vcpu->arch.switch_db_regs &= ~KVM_DEBUGREG_BP_ENABLED;
    	if (dr7 & DR7_BP_EN_MASK)
    		vcpu->arch.switch_db_regs |= KVM_DEBUGREG_BP_ENABLED;
    }
    
    static u64 kvm_dr6_fixed(struct kvm_vcpu *vcpu)
    {
    	u64 fixed = DR6_FIXED_1;
    
    	if (!guest_cpuid_has(vcpu, X86_FEATURE_RTM))
    		fixed |= DR6_RTM;
    	return fixed;
    }
    
    static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
    {
    	switch (dr) {
    	case 0 ... 3:
    		vcpu->arch.db[dr] = val;
    		if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP))
    			vcpu->arch.eff_db[dr] = val;
    		break;
    	case 4:
    		/* fall through */
    	case 6:
    		if (val & 0xffffffff00000000ULL)
    			return -1; /* #GP */
    		vcpu->arch.dr6 = (val & DR6_VOLATILE) | kvm_dr6_fixed(vcpu);
    		kvm_update_dr6(vcpu);
    		break;
    	case 5:
    		/* fall through */
    	default: /* 7 */
    		if (val & 0xffffffff00000000ULL)
    			return -1; /* #GP */
    		vcpu->arch.dr7 = (val & DR7_VOLATILE) | DR7_FIXED_1;
    		kvm_update_dr7(vcpu);
    		break;
    	}
    
    	return 0;
    }
    
    int kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
    {
    	if (__kvm_set_dr(vcpu, dr, val)) {
    		kvm_inject_gp(vcpu, 0);
    		return 1;
    	}
    	return 0;
    }
    EXPORT_SYMBOL_GPL(kvm_set_dr);
    
    int kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val)
    {
    	switch (dr) {
    	case 0 ... 3:
    		*val = vcpu->arch.db[dr];
    		break;
    	case 4:
    		/* fall through */
    	case 6:
    		if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
    			*val = vcpu->arch.dr6;
    		else
    			*val = kvm_x86_ops->get_dr6(vcpu);
    		break;
    	case 5:
    		/* fall through */
    	default: /* 7 */
    		*val = vcpu->arch.dr7;
    		break;
    	}
    	return 0;
    }
    EXPORT_SYMBOL_GPL(kvm_get_dr);
    
    bool kvm_rdpmc(struct kvm_vcpu *vcpu)
    {
    	u32 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX);
    	u64 data;
    	int err;
    
    	err = kvm_pmu_rdpmc(vcpu, ecx, &data);
    	if (err)
    		return err;
    	kvm_register_write(vcpu, VCPU_REGS_RAX, (u32)data);
    	kvm_register_write(vcpu, VCPU_REGS_RDX, data >> 32);
    	return err;
    }
    EXPORT_SYMBOL_GPL(kvm_rdpmc);
    
    /*
     * List of msr numbers which we expose to userspace through KVM_GET_MSRS
     * and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST.
     *
     * This list is modified at module load time to reflect the
     * capabilities of the host cpu. This capabilities test skips MSRs that are
     * kvm-specific. Those are put in emulated_msrs; filtering of emulated_msrs
     * may depend on host virtualization features rather than host cpu features.
     */
    
    static u32 msrs_to_save[] = {
    	MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
    	MSR_STAR,
    #ifdef CONFIG_X86_64
    	MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR,
    #endif
    	MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA,
    	MSR_IA32_FEATURE_CONTROL, MSR_IA32_BNDCFGS, MSR_TSC_AUX,
    	MSR_IA32_SPEC_CTRL, MSR_IA32_ARCH_CAPABILITIES
    };
    
    static unsigned num_msrs_to_save;
    
    static u32 emulated_msrs[] = {
    	MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK,
    	MSR_KVM_SYSTEM_TIME_NEW, MSR_KVM_WALL_CLOCK_NEW,
    	HV_X64_MSR_GUEST_OS_ID, HV_X64_MSR_HYPERCALL,
    	HV_X64_MSR_TIME_REF_COUNT, HV_X64_MSR_REFERENCE_TSC,
    	HV_X64_MSR_TSC_FREQUENCY, HV_X64_MSR_APIC_FREQUENCY,
    	HV_X64_MSR_CRASH_P0, HV_X64_MSR_CRASH_P1, HV_X64_MSR_CRASH_P2,
    	HV_X64_MSR_CRASH_P3, HV_X64_MSR_CRASH_P4, HV_X64_MSR_CRASH_CTL,
    	HV_X64_MSR_RESET,
    	HV_X64_MSR_VP_INDEX,
    	HV_X64_MSR_VP_RUNTIME,
    	HV_X64_MSR_SCONTROL,
    	HV_X64_MSR_STIMER0_CONFIG,
    	HV_X64_MSR_VP_ASSIST_PAGE,
    	HV_X64_MSR_REENLIGHTENMENT_CONTROL, HV_X64_MSR_TSC_EMULATION_CONTROL,
    	HV_X64_MSR_TSC_EMULATION_STATUS,
    
    	MSR_KVM_ASYNC_PF_EN, MSR_KVM_STEAL_TIME,
    	MSR_KVM_PV_EOI_EN,
    
    	MSR_IA32_TSC_ADJUST,
    	MSR_IA32_TSCDEADLINE,
    	MSR_IA32_MISC_ENABLE,
    	MSR_IA32_MCG_STATUS,
    	MSR_IA32_MCG_CTL,
    	MSR_IA32_MCG_EXT_CTL,
    	MSR_IA32_SMBASE,
    	MSR_SMI_COUNT,
    	MSR_PLATFORM_INFO,
    	MSR_MISC_FEATURES_ENABLES,
    	MSR_AMD64_VIRT_SPEC_CTRL,
    };
    
    static unsigned num_emulated_msrs;
    
    /*
     * List of msr numbers which are used to expose MSR-based features that
     * can be used by a hypervisor to validate requested CPU features.
     */
    static u32 msr_based_features[] = {
    	MSR_IA32_VMX_BASIC,
    	MSR_IA32_VMX_TRUE_PINBASED_CTLS,
    	MSR_IA32_VMX_PINBASED_CTLS,
    	MSR_IA32_VMX_TRUE_PROCBASED_CTLS,
    	MSR_IA32_VMX_PROCBASED_CTLS,
    	MSR_IA32_VMX_TRUE_EXIT_CTLS,
    	MSR_IA32_VMX_EXIT_CTLS,
    	MSR_IA32_VMX_TRUE_ENTRY_CTLS,
    	MSR_IA32_VMX_ENTRY_CTLS,
    	MSR_IA32_VMX_MISC,
    	MSR_IA32_VMX_CR0_FIXED0,
    	MSR_IA32_VMX_CR0_FIXED1,
    	MSR_IA32_VMX_CR4_FIXED0,
    	MSR_IA32_VMX_CR4_FIXED1,
    	MSR_IA32_VMX_VMCS_ENUM,
    	MSR_IA32_VMX_PROCBASED_CTLS2,
    	MSR_IA32_VMX_EPT_VPID_CAP,
    	MSR_IA32_VMX_VMFUNC,
    
    	MSR_F10H_DECFG,
    	MSR_IA32_UCODE_REV,
    	MSR_IA32_ARCH_CAPABILITIES,
    };
    
    static unsigned int num_msr_based_features;
    
    u64 kvm_get_arch_capabilities(void)
    {
    	u64 data;
    
    	rdmsrl_safe(MSR_IA32_ARCH_CAPABILITIES, &data);
    
    	/*
    	 * If we're doing cache flushes (either "always" or "cond")
    	 * we will do one whenever the guest does a vmlaunch/vmresume.
    	 * If an outer hypervisor is doing the cache flush for us
    	 * (VMENTER_L1D_FLUSH_NESTED_VM), we can safely pass that
    	 * capability to the guest too, and if EPT is disabled we're not
    	 * vulnerable.  Overall, only VMENTER_L1D_FLUSH_NEVER will
    	 * require a nested hypervisor to do a flush of its own.
    	 */
    	if (l1tf_vmx_mitigation != VMENTER_L1D_FLUSH_NEVER)
    		data |= ARCH_CAP_SKIP_VMENTRY_L1DFLUSH;
    
    	return data;
    }
    EXPORT_SYMBOL_GPL(kvm_get_arch_capabilities);
    
    static int kvm_get_msr_feature(struct kvm_msr_entry *msr)
    {
    	switch (msr->index) {
    	case MSR_IA32_ARCH_CAPABILITIES:
    		msr->data = kvm_get_arch_capabilities();
    		break;
    	case MSR_IA32_UCODE_REV:
    		rdmsrl_safe(msr->index, &msr->data);
    		break;
    	default:
    		if (kvm_x86_ops->get_msr_feature(msr))
    			return 1;
    	}
    	return 0;
    }
    
    static int do_get_msr_feature(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
    {
    	struct kvm_msr_entry msr;
    	int r;
    
    	msr.index = index;
    	r = kvm_get_msr_feature(&msr);
    	if (r)
    		return r;
    
    	*data = msr.data;
    
    	return 0;
    }
    
    bool kvm_valid_efer(struct kvm_vcpu *vcpu, u64 efer)
    {
    	if (efer & efer_reserved_bits)
    		return false;
    
    	if (efer & EFER_FFXSR && !guest_cpuid_has(vcpu, X86_FEATURE_FXSR_OPT))
    			return false;
    
    	if (efer & EFER_SVME && !guest_cpuid_has(vcpu, X86_FEATURE_SVM))
    			return false;
    
    	return true;
    }
    EXPORT_SYMBOL_GPL(kvm_valid_efer);
    
    static int set_efer(struct kvm_vcpu *vcpu, u64 efer)
    {
    	u64 old_efer = vcpu->arch.efer;
    
    	if (!kvm_valid_efer(vcpu, efer))
    		return 1;
    
    	if (is_paging(vcpu)
    	    && (vcpu->arch.efer & EFER_LME) != (efer & EFER_LME))
    		return 1;
    
    	efer &= ~EFER_LMA;
    	efer |= vcpu->arch.efer & EFER_LMA;
    
    	kvm_x86_ops->set_efer(vcpu, efer);
    
    	/* Update reserved bits */
    	if ((efer ^ old_efer) & EFER_NX)
    		kvm_mmu_reset_context(vcpu);
    
    	return 0;
    }
    
    void kvm_enable_efer_bits(u64 mask)
    {
           efer_reserved_bits &= ~mask;
    }
    EXPORT_SYMBOL_GPL(kvm_enable_efer_bits);
    
    /*
     * Writes msr value into into the appropriate "register".
     * Returns 0 on success, non-0 otherwise.
     * Assumes vcpu_load() was already called.
     */
    int kvm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
    {
    	switch (msr->index) {
    	case MSR_FS_BASE:
    	case MSR_GS_BASE:
    	case MSR_KERNEL_GS_BASE:
    	case MSR_CSTAR:
    	case MSR_LSTAR:
    		if (is_noncanonical_address(msr->data, vcpu))
    			return 1;
    		break;
    	case MSR_IA32_SYSENTER_EIP:
    	case MSR_IA32_SYSENTER_ESP:
    		/*
    		 * IA32_SYSENTER_ESP and IA32_SYSENTER_EIP cause #GP if
    		 * non-canonical address is written on Intel but not on
    		 * AMD (which ignores the top 32-bits, because it does
    		 * not implement 64-bit SYSENTER).
    		 *
    		 * 64-bit code should hence be able to write a non-canonical
    		 * value on AMD.  Making the address canonical ensures that
    		 * vmentry does not fail on Intel after writing a non-canonical
    		 * value, and that something deterministic happens if the guest
    		 * invokes 64-bit SYSENTER.
    		 */
    		msr->data = get_canonical(msr->data, vcpu_virt_addr_bits(vcpu));
    	}
    	return kvm_x86_ops->set_msr(vcpu, msr);
    }
    EXPORT_SYMBOL_GPL(kvm_set_msr);
    
    /*
     * Adapt set_msr() to msr_io()'s calling convention
     */
    static int do_get_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
    {
    	struct msr_data msr;
    	int r;
    
    	msr.index = index;
    	msr.host_initiated = true;
    	r = kvm_get_msr(vcpu, &msr);
    	if (r)
    		return r;
    
    	*data = msr.data;
    	return 0;
    }
    
    static int do_set_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
    {
    	struct msr_data msr;
    
    	msr.data = *data;
    	msr.index = index;
    	msr.host_initiated = true;
    	return kvm_set_msr(vcpu, &msr);
    }
    
    #ifdef CONFIG_X86_64
    struct pvclock_gtod_data {
    	seqcount_t	seq;
    
    	struct { /* extract of a clocksource struct */
    		int vclock_mode;
    		u64	cycle_last;
    		u64	mask;
    		u32	mult;
    		u32	shift;
    	} clock;
    
    	u64		boot_ns;
    	u64		nsec_base;
    	u64		wall_time_sec;
    };
    
    static struct pvclock_gtod_data pvclock_gtod_data;
    
    static void update_pvclock_gtod(struct timekeeper *tk)
    {
    	struct pvclock_gtod_data *vdata = &pvclock_gtod_data;
    	u64 boot_ns;
    
    	boot_ns = ktime_to_ns(ktime_add(tk->tkr_mono.base, tk->offs_boot));
    
    	write_seqcount_begin(&vdata->seq);
    
    	/* copy pvclock gtod data */
    	vdata->clock.vclock_mode	= tk->tkr_mono.clock->archdata.vclock_mode;
    	vdata->clock.cycle_last		= tk->tkr_mono.cycle_last;
    	vdata->clock.mask		= tk->tkr_mono.mask;
    	vdata->clock.mult		= tk->tkr_mono.mult;
    	vdata->clock.shift		= tk->tkr_mono.shift;
    
    	vdata->boot_ns			= boot_ns;
    	vdata->nsec_base		= tk->tkr_mono.xtime_nsec;
    
    	vdata->wall_time_sec            = tk->xtime_sec;
    
    	write_seqcount_end(&vdata->seq);
    }
    #endif
    
    void kvm_set_pending_timer(struct kvm_vcpu *vcpu)
    {
    	/*
    	 * Note: KVM_REQ_PENDING_TIMER is implicitly checked in
    	 * vcpu_enter_guest.  This function is only called from
    	 * the physical CPU that is running vcpu.
    	 */
    	kvm_make_request(KVM_REQ_PENDING_TIMER, vcpu);
    }
    
    static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock)
    {
    	int version;
    	int r;
    	struct pvclock_wall_clock wc;
    	struct timespec64 boot;
    
    	if (!wall_clock)
    		return;
    
    	r = kvm_read_guest(kvm, wall_clock, &version, sizeof(version));
    	if (r)
    		return;
    
    	if (version & 1)
    		++version;  /* first time write, random junk */
    
    	++version;
    
    	if (kvm_write_guest(kvm, wall_clock, &version, sizeof(version)))
    		return;
    
    	/*
    	 * The guest calculates current wall clock time by adding
    	 * system time (updated by kvm_guest_time_update below) to the
    	 * wall clock specified here.  guest system time equals host
    	 * system time for us, thus we must fill in host boot time here.
    	 */
    	getboottime64(&boot);
    
    	if (kvm->arch.kvmclock_offset) {
    		struct timespec64 ts = ns_to_timespec64(kvm->arch.kvmclock_offset);
    		boot = timespec64_sub(boot, ts);
    	}
    	wc.sec = (u32)boot.tv_sec; /* overflow in 2106 guest time */
    	wc.nsec = boot.tv_nsec;
    	wc.version = version;
    
    	kvm_write_guest(kvm, wall_clock, &wc, sizeof(wc));
    
    	version++;
    	kvm_write_guest(kvm, wall_clock, &version, sizeof(version));
    }
    
    static uint32_t div_frac(uint32_t dividend, uint32_t divisor)
    {
    	do_shl32_div32(dividend, divisor);
    	return dividend;
    }
    
    static void kvm_get_time_scale(uint64_t scaled_hz, uint64_t base_hz,
    			       s8 *pshift, u32 *pmultiplier)
    {
    	uint64_t scaled64;
    	int32_t  shift = 0;
    	uint64_t tps64;
    	uint32_t tps32;
    
    	tps64 = base_hz;
    	scaled64 = scaled_hz;
    	while (tps64 > scaled64*2 || tps64 & 0xffffffff00000000ULL) {
    		tps64 >>= 1;
    		shift--;
    	}
    
    	tps32 = (uint32_t)tps64;
    	while (tps32 <= scaled64 || scaled64 & 0xffffffff00000000ULL) {
    		if (scaled64 & 0xffffffff00000000ULL || tps32 & 0x80000000)
    			scaled64 >>= 1;
    		else
    			tps32 <<= 1;
    		shift++;
    	}
    
    	*pshift = shift;
    	*pmultiplier = div_frac(scaled64, tps32);
    
    	pr_debug("%s: base_hz %llu => %llu, shift %d, mul %u\n",
    		 __func__, base_hz, scaled_hz, shift, *pmultiplier);
    }
    
    #ifdef CONFIG_X86_64
    static atomic_t kvm_guest_has_master_clock = ATOMIC_INIT(0);
    #endif
    
    static DEFINE_PER_CPU(unsigned long, cpu_tsc_khz);
    static unsigned long max_tsc_khz;
    
    static u32 adjust_tsc_khz(u32 khz, s32 ppm)
    {
    	u64 v = (u64)khz * (1000000 + ppm);
    	do_div(v, 1000000);
    	return v;
    }
    
    static int set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale)
    {
    	u64 ratio;
    
    	/* Guest TSC same frequency as host TSC? */
    	if (!scale) {
    		vcpu->arch.tsc_scaling_ratio = kvm_default_tsc_scaling_ratio;
    		return 0;
    	}
    
    	/* TSC scaling supported? */
    	if (!kvm_has_tsc_control) {
    		if (user_tsc_khz > tsc_khz) {
    			vcpu->arch.tsc_catchup = 1;
    			vcpu->arch.tsc_always_catchup = 1;
    			return 0;
    		} else {
    			WARN(1, "user requested TSC rate below hardware speed\n");
    			return -1;
    		}
    	}
    
    	/* TSC scaling required  - calculate ratio */
    	ratio = mul_u64_u32_div(1ULL << kvm_tsc_scaling_ratio_frac_bits,
    				user_tsc_khz, tsc_khz);
    
    	if (ratio == 0 || ratio >= kvm_max_tsc_scaling_ratio) {
    		WARN_ONCE(1, "Invalid TSC scaling ratio - virtual-tsc-khz=%u\n",
    			  user_tsc_khz);
    		return -1;
    	}
    
    	vcpu->arch.tsc_scaling_ratio = ratio;
    	return 0;
    }
    
    static int kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz)
    {
    	u32 thresh_lo, thresh_hi;
    	int use_scaling = 0;
    
    	/* tsc_khz can be zero if TSC calibration fails */
    	if (user_tsc_khz == 0) {
    		/* set tsc_scaling_ratio to a safe value */
    		vcpu->arch.tsc_scaling_ratio = kvm_default_tsc_scaling_ratio;
    		return -1;
    	}
    
    	/* Compute a scale to convert nanoseconds in TSC cycles */
    	kvm_get_time_scale(user_tsc_khz * 1000LL, NSEC_PER_SEC,
    			   &vcpu->arch.virtual_tsc_shift,
    			   &vcpu->arch.virtual_tsc_mult);
    	vcpu->arch.virtual_tsc_khz = user_tsc_khz;
    
    	/*
    	 * Compute the variation in TSC rate which is acceptable
    	 * within the range of tolerance and decide if the
    	 * rate being applied is within that bounds of the hardware
    	 * rate.  If so, no scaling or compensation need be done.
    	 */
    	thresh_lo = adjust_tsc_khz(tsc_khz, -tsc_tolerance_ppm);
    	thresh_hi = adjust_tsc_khz(tsc_khz, tsc_tolerance_ppm);
    	if (user_tsc_khz < thresh_lo || user_tsc_khz > thresh_hi) {
    		pr_debug("kvm: requested TSC rate %u falls outside tolerance [%u,%u]\n", user_tsc_khz, thresh_lo, thresh_hi);
    		use_scaling = 1;
    	}
    	return set_tsc_khz(vcpu, user_tsc_khz, use_scaling);
    }
    
    static u64 compute_guest_tsc(struct kvm_vcpu *vcpu, s64 kernel_ns)
    {
    	u64 tsc = pvclock_scale_delta(kernel_ns-vcpu->arch.this_tsc_nsec,
    				      vcpu->arch.virtual_tsc_mult,
    				      vcpu->arch.virtual_tsc_shift);
    	tsc += vcpu->arch.this_tsc_write;
    	return tsc;
    }
    
    static inline int gtod_is_based_on_tsc(int mode)
    {
    	return mode == VCLOCK_TSC || mode == VCLOCK_HVCLOCK;
    }
    
    static void kvm_track_tsc_matching(struct kvm_vcpu *vcpu)
    {
    #ifdef CONFIG_X86_64
    	bool vcpus_matched;
    	struct kvm_arch *ka = &vcpu->kvm->arch;
    	struct pvclock_gtod_data *gtod = &pvclock_gtod_data;
    
    	vcpus_matched = (ka->nr_vcpus_matched_tsc + 1 ==
    			 atomic_read(&vcpu->kvm->online_vcpus));
    
    	/*
    	 * Once the masterclock is enabled, always perform request in
    	 * order to update it.
    	 *
    	 * In order to enable masterclock, the host clocksource must be TSC
    	 * and the vcpus need to have matched TSCs.  When that happens,
    	 * perform request to enable masterclock.
    	 */
    	if (ka->use_master_clock ||
    	    (gtod_is_based_on_tsc(gtod->clock.vclock_mode) && vcpus_matched))
    		kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
    
    	trace_kvm_track_tsc(vcpu->vcpu_id, ka->nr_vcpus_matched_tsc,
    			    atomic_read(&vcpu->kvm->online_vcpus),
    		            ka->use_master_clock, gtod->clock.vclock_mode);
    #endif
    }
    
    static void update_ia32_tsc_adjust_msr(struct kvm_vcpu *vcpu, s64 offset)
    {
    	u64 curr_offset = kvm_x86_ops->read_l1_tsc_offset(vcpu);
    	vcpu->arch.ia32_tsc_adjust_msr += offset - curr_offset;
    }
    
    /*
     * Multiply tsc by a fixed point number represented by ratio.
     *
     * The most significant 64-N bits (mult) of ratio represent the
     * integral part of the fixed point number; the remaining N bits
     * (frac) represent the fractional part, ie. ratio represents a fixed
     * point number (mult + frac * 2^(-N)).
     *
     * N equals to kvm_tsc_scaling_ratio_frac_bits.
     */
    static inline u64 __scale_tsc(u64 ratio, u64 tsc)
    {
    	return mul_u64_u64_shr(tsc, ratio, kvm_tsc_scaling_ratio_frac_bits);
    }
    
    u64 kvm_scale_tsc(struct kvm_vcpu *vcpu, u64 tsc)
    {
    	u64 _tsc = tsc;
    	u64 ratio = vcpu->arch.tsc_scaling_ratio;
    
    	if (ratio != kvm_default_tsc_scaling_ratio)
    		_tsc = __scale_tsc(ratio, tsc);
    
    	return _tsc;
    }
    EXPORT_SYMBOL_GPL(kvm_scale_tsc);
    
    static u64 kvm_compute_tsc_offset(struct kvm_vcpu *vcpu, u64 target_tsc)
    {
    	u64 tsc;
    
    	tsc = kvm_scale_tsc(vcpu, rdtsc());
    
    	return target_tsc - tsc;
    }
    
    u64 kvm_read_l1_tsc(struct kvm_vcpu *vcpu, u64 host_tsc)
    {
    	u64 tsc_offset = kvm_x86_ops->read_l1_tsc_offset(vcpu);
    
    	return tsc_offset + kvm_scale_tsc(vcpu, host_tsc);
    }
    EXPORT_SYMBOL_GPL(kvm_read_l1_tsc);
    
    static void kvm_vcpu_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset)
    {
    	kvm_x86_ops->write_tsc_offset(vcpu, offset);
    	vcpu->arch.tsc_offset = offset;
    }
    
    static inline bool kvm_check_tsc_unstable(void)
    {
    #ifdef CONFIG_X86_64
    	/*
    	 * TSC is marked unstable when we're running on Hyper-V,
    	 * 'TSC page' clocksource is good.
    	 */
    	if (pvclock_gtod_data.clock.vclock_mode == VCLOCK_HVCLOCK)
    		return false;
    #endif
    	return check_tsc_unstable();
    }
    
    void kvm_write_tsc(struct kvm_vcpu *vcpu, struct msr_data *msr)
    {
    	struct kvm *kvm = vcpu->kvm;
    	u64 offset, ns, elapsed;
    	unsigned long flags;
    	bool matched;
    	bool already_matched;
    	u64 data = msr->data;
    	bool synchronizing = false;
    
    	raw_spin_lock_irqsave(&kvm->arch.tsc_write_lock, flags);
    	offset = kvm_compute_tsc_offset(vcpu, data);
    	ns = ktime_get_boot_ns();
    	elapsed = ns - kvm->arch.last_tsc_nsec;
    
    	if (vcpu->arch.virtual_tsc_khz) {
    		if (data == 0 && msr->host_initiated) {
    			/*
    			 * detection of vcpu initialization -- need to sync
    			 * with other vCPUs. This particularly helps to keep
    			 * kvm_clock stable after CPU hotplug
    			 */
    			synchronizing = true;
    		} else {
    			u64 tsc_exp = kvm->arch.last_tsc_write +
    						nsec_to_cycles(vcpu, elapsed);
    			u64 tsc_hz = vcpu->arch.virtual_tsc_khz * 1000LL;
    			/*
    			 * Special case: TSC write with a small delta (1 second)
    			 * of virtual cycle time against real time is
    			 * interpreted as an attempt to synchronize the CPU.
    			 */
    			synchronizing = data < tsc_exp + tsc_hz &&
    					data + tsc_hz > tsc_exp;
    		}
    	}
    
    	/*
    	 * For a reliable TSC, we can match TSC offsets, and for an unstable
    	 * TSC, we add elapsed time in this computation.  We could let the
    	 * compensation code attempt to catch up if we fall behind, but
    	 * it's better to try to match offsets from the beginning.
             */
    	if (synchronizing &&
    	    vcpu->arch.virtual_tsc_khz == kvm->arch.last_tsc_khz) {
    		if (!kvm_check_tsc_unstable()) {
    			offset = kvm->arch.cur_tsc_offset;
    			pr_debug("kvm: matched tsc offset for %llu\n", data);
    		} else {
    			u64 delta = nsec_to_cycles(vcpu, elapsed);
    			data += delta;
    			offset = kvm_compute_tsc_offset(vcpu, data);
    			pr_debug("kvm: adjusted tsc offset by %llu\n", delta);
    		}
    		matched = true;
    		already_matched = (vcpu->arch.this_tsc_generation == kvm->arch.cur_tsc_generation);
    	} else {
    		/*
    		 * We split periods of matched TSC writes into generations.
    		 * For each generation, we track the original measured
    		 * nanosecond time, offset, and write, so if TSCs are in
    		 * sync, we can match exact offset, and if not, we can match
    		 * exact software computation in compute_guest_tsc()
    		 *
    		 * These values are tracked in kvm->arch.cur_xxx variables.
    		 */
    		kvm->arch.cur_tsc_generation++;
    		kvm->arch.cur_tsc_nsec = ns;
    		kvm->arch.cur_tsc_write = data;
    		kvm->arch.cur_tsc_offset = offset;
    		matched = false;
    		pr_debug("kvm: new tsc generation %llu, clock %llu\n",
    			 kvm->arch.cur_tsc_generation, data);
    	}
    
    	/*
    	 * We also track th most recent recorded KHZ, write and time to
    	 * allow the matching interval to be extended at each write.
    	 */
    	kvm->arch.last_tsc_nsec = ns;
    	kvm->arch.last_tsc_write = data;
    	kvm->arch.last_tsc_khz = vcpu->arch.virtual_tsc_khz;
    
    	vcpu->arch.last_guest_tsc = data;
    
    	/* Keep track of which generation this VCPU has synchronized to */
    	vcpu->arch.this_tsc_generation = kvm->arch.cur_tsc_generation;
    	vcpu->arch.this_tsc_nsec = kvm->arch.cur_tsc_nsec;
    	vcpu->arch.this_tsc_write = kvm->arch.cur_tsc_write;
    
    	if (!msr->host_initiated && guest_cpuid_has(vcpu, X86_FEATURE_TSC_ADJUST))
    		update_ia32_tsc_adjust_msr(vcpu, offset);
    
    	kvm_vcpu_write_tsc_offset(vcpu, offset);
    	raw_spin_unlock_irqrestore(&kvm->arch.tsc_write_lock, flags);
    
    	spin_lock(&kvm->arch.pvclock_gtod_sync_lock);
    	if (!matched) {
    		kvm->arch.nr_vcpus_matched_tsc = 0;
    	} else if (!already_matched) {
    		kvm->arch.nr_vcpus_matched_tsc++;
    	}
    
    	kvm_track_tsc_matching(vcpu);
    	spin_unlock(&kvm->arch.pvclock_gtod_sync_lock);
    }
    
    EXPORT_SYMBOL_GPL(kvm_write_tsc);
    
    static inline void adjust_tsc_offset_guest(struct kvm_vcpu *vcpu,
    					   s64 adjustment)
    {
    	kvm_vcpu_write_tsc_offset(vcpu, vcpu->arch.tsc_offset + adjustment);
    }
    
    static inline void adjust_tsc_offset_host(struct kvm_vcpu *vcpu, s64 adjustment)
    {
    	if (vcpu->arch.tsc_scaling_ratio != kvm_default_tsc_scaling_ratio)
    		WARN_ON(adjustment < 0);
    	adjustment = kvm_scale_tsc(vcpu, (u64) adjustment);
    	adjust_tsc_offset_guest(vcpu, adjustment);
    }
    
    #ifdef CONFIG_X86_64
    
    static u64 read_tsc(void)
    {
    	u64 ret = (u64)rdtsc_ordered();
    	u64 last = pvclock_gtod_data.clock.cycle_last;
    
    	if (likely(ret >= last))
    		return ret;
    
    	/*
    	 * GCC likes to generate cmov here, but this branch is extremely
    	 * predictable (it's just a function of time and the likely is
    	 * very likely) and there's a data dependence, so force GCC
    	 * to generate a branch instead.  I don't barrier() because
    	 * we don't actually need a barrier, and if this function
    	 * ever gets inlined it will generate worse code.
    	 */
    	asm volatile ("");
    	return last;
    }
    
    static inline u64 vgettsc(u64 *tsc_timestamp, int *mode)
    {
    	long v;
    	struct pvclock_gtod_data *gtod = &pvclock_gtod_data;
    	u64 tsc_pg_val;
    
    	switch (gtod->clock.vclock_mode) {
    	case VCLOCK_HVCLOCK:
    		tsc_pg_val = hv_read_tsc_page_tsc(hv_get_tsc_page(),
    						  tsc_timestamp);
    		if (tsc_pg_val != U64_MAX) {
    			/* TSC page valid */
    			*mode = VCLOCK_HVCLOCK;
    			v = (tsc_pg_val - gtod->clock.cycle_last) &
    				gtod->clock.mask;
    		} else {
    			/* TSC page invalid */
    			*mode = VCLOCK_NONE;
    		}
    		break;
    	case VCLOCK_TSC:
    		*mode = VCLOCK_TSC;
    		*tsc_timestamp = read_tsc();
    		v = (*tsc_timestamp - gtod->clock.cycle_last) &
    			gtod->clock.mask;
    		break;
    	default:
    		*mode = VCLOCK_NONE;
    	}
    
    	if (*mode == VCLOCK_NONE)
    		*tsc_timestamp = v = 0;
    
    	return v * gtod->clock.mult;
    }
    
    static int do_monotonic_boot(s64 *t, u64 *tsc_timestamp)
    {
    	struct pvclock_gtod_data *gtod = &pvclock_gtod_data;
    	unsigned long seq;
    	int mode;
    	u64 ns;
    
    	do {
    		seq = read_seqcount_begin(&gtod->seq);
    		ns = gtod->nsec_base;
    		ns += vgettsc(tsc_timestamp, &mode);
    		ns >>= gtod->clock.shift;
    		ns += gtod->boot_ns;
    	} while (unlikely(read_seqcount_retry(&gtod->seq, seq)));
    	*t = ns;
    
    	return mode;
    }
    
    static int do_realtime(struct timespec64 *ts, u64 *tsc_timestamp)
    {
    	struct pvclock_gtod_data *gtod = &pvclock_gtod_data;
    	unsigned long seq;
    	int mode;
    	u64 ns;
    
    	do {
    		seq = read_seqcount_begin(&gtod->seq);
    		ts->tv_sec = gtod->wall_time_sec;
    		ns = gtod->nsec_base;
    		ns += vgettsc(tsc_timestamp, &mode);
    		ns >>= gtod->clock.shift;
    	} while (unlikely(read_seqcount_retry(&gtod->seq, seq)));
    
    	ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
    	ts->tv_nsec = ns;
    
    	return mode;
    }
    
    /* returns true if host is using TSC based clocksource */
    static bool kvm_get_time_and_clockread(s64 *kernel_ns, u64 *tsc_timestamp)
    {
    	/* checked again under seqlock below */
    	if (!gtod_is_based_on_tsc(pvclock_gtod_data.clock.vclock_mode))
    		return false;
    
    	return gtod_is_based_on_tsc(do_monotonic_boot(kernel_ns,
    						      tsc_timestamp));
    }
    
    /* returns true if host is using TSC based clocksource */
    static bool kvm_get_walltime_and_clockread(struct timespec64 *ts,
    					   u64 *tsc_timestamp)
    {
    	/* checked again under seqlock below */
    	if (!gtod_is_based_on_tsc(pvclock_gtod_data.clock.vclock_mode))
    		return false;
    
    	return gtod_is_based_on_tsc(do_realtime(ts, tsc_timestamp));
    }
    #endif
    
    /*
     *
     * Assuming a stable TSC across physical CPUS, and a stable TSC
     * across virtual CPUs, the following condition is possible.
     * Each numbered line represents an event visible to both
     * CPUs at the next numbered event.
     *
     * "timespecX" represents host monotonic time. "tscX" represents
     * RDTSC value.
     *
     * 		VCPU0 on CPU0		|	VCPU1 on CPU1
     *
     * 1.  read timespec0,tsc0
     * 2.					| timespec1 = timespec0 + N
     * 					| tsc1 = tsc0 + M
     * 3. transition to guest		| transition to guest
     * 4. ret0 = timespec0 + (rdtsc - tsc0) |
     * 5.				        | ret1 = timespec1 + (rdtsc - tsc1)
     * 				        | ret1 = timespec0 + N + (rdtsc - (tsc0 + M))
     *
     * Since ret0 update is visible to VCPU1 at time 5, to obey monotonicity:
     *
     * 	- ret0 < ret1
     *	- timespec0 + (rdtsc - tsc0) < timespec0 + N + (rdtsc - (tsc0 + M))
     *		...
     *	- 0 < N - M => M < N
     *
     * That is, when timespec0 != timespec1, M < N. Unfortunately that is not
     * always the case (the difference between two distinct xtime instances
     * might be smaller then the difference between corresponding TSC reads,
     * when updating guest vcpus pvclock areas).
     *
     * To avoid that problem, do not allow visibility of distinct
     * system_timestamp/tsc_timestamp values simultaneously: use a master
     * copy of host monotonic time values. Update that master copy
     * in lockstep.
     *
     * Rely on synchronization of host TSCs and guest TSCs for monotonicity.
     *
     */
    
    static void pvclock_update_vm_gtod_copy(struct kvm *kvm)
    {
    #ifdef CONFIG_X86_64
    	struct kvm_arch *ka = &kvm->arch;
    	int vclock_mode;
    	bool host_tsc_clocksource, vcpus_matched;
    
    	vcpus_matched = (ka->nr_vcpus_matched_tsc + 1 ==
    			atomic_read(&kvm->online_vcpus));
    
    	/*
    	 * If the host uses TSC clock, then passthrough TSC as stable
    	 * to the guest.
    	 */
    	host_tsc_clocksource = kvm_get_time_and_clockread(
    					&ka->master_kernel_ns,
    					&ka->master_cycle_now);
    
    	ka->use_master_clock = host_tsc_clocksource && vcpus_matched
    				&& !ka->backwards_tsc_observed
    				&& !ka->boot_vcpu_runs_old_kvmclock;
    
    	if (ka->use_master_clock)
    		atomic_set(&kvm_guest_has_master_clock, 1);
    
    	vclock_mode = pvclock_gtod_data.clock.vclock_mode;
    	trace_kvm_update_master_clock(ka->use_master_clock, vclock_mode,
    					vcpus_matched);
    #endif
    }
    
    void kvm_make_mclock_inprogress_request(struct kvm *kvm)
    {
    	kvm_make_all_cpus_request(kvm, KVM_REQ_MCLOCK_INPROGRESS);
    }
    
    static void kvm_gen_update_masterclock(struct kvm *kvm)
    {
    #ifdef CONFIG_X86_64
    	int i;
    	struct kvm_vcpu *vcpu;
    	struct kvm_arch *ka = &kvm->arch;
    
    	spin_lock(&ka->pvclock_gtod_sync_lock);
    	kvm_make_mclock_inprogress_request(kvm);
    	/* no guest entries from this point */
    	pvclock_update_vm_gtod_copy(kvm);
    
    	kvm_for_each_vcpu(i, vcpu, kvm)
    		kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
    
    	/* guest entries allowed */
    	kvm_for_each_vcpu(i, vcpu, kvm)
    		kvm_clear_request(KVM_REQ_MCLOCK_INPROGRESS, vcpu);
    
    	spin_unlock(&ka->pvclock_gtod_sync_lock);
    #endif
    }
    
    u64 get_kvmclock_ns(struct kvm *kvm)
    {
    	struct kvm_arch *ka = &kvm->arch;
    	struct pvclock_vcpu_time_info hv_clock;
    	u64 ret;
    
    	spin_lock(&ka->pvclock_gtod_sync_lock);
    	if (!ka->use_master_clock) {
    		spin_unlock(&ka->pvclock_gtod_sync_lock);
    		return ktime_get_boot_ns() + ka->kvmclock_offset;
    	}
    
    	hv_clock.tsc_timestamp = ka->master_cycle_now;
    	hv_clock.system_time = ka->master_kernel_ns + ka->kvmclock_offset;
    	spin_unlock(&ka->pvclock_gtod_sync_lock);
    
    	/* both __this_cpu_read() and rdtsc() should be on the same cpu */
    	get_cpu();
    
    	if (__this_cpu_read(cpu_tsc_khz)) {
    		kvm_get_time_scale(NSEC_PER_SEC, __this_cpu_read(cpu_tsc_khz) * 1000LL,
    				   &hv_clock.tsc_shift,
    				   &hv_clock.tsc_to_system_mul);
    		ret = __pvclock_read_cycles(&hv_clock, rdtsc());
    	} else
    		ret = ktime_get_boot_ns() + ka->kvmclock_offset;
    
    	put_cpu();
    
    	return ret;
    }
    
    static void kvm_setup_pvclock_page(struct kvm_vcpu *v)
    {
    	struct kvm_vcpu_arch *vcpu = &v->arch;
    	struct pvclock_vcpu_time_info guest_hv_clock;
    
    	if (unlikely(kvm_read_guest_cached(v->kvm, &vcpu->pv_time,
    		&guest_hv_clock, sizeof(guest_hv_clock))))
    		return;
    
    	/* This VCPU is paused, but it's legal for a guest to read another
    	 * VCPU's kvmclock, so we really have to follow the specification where
    	 * it says that version is odd if data is being modified, and even after
    	 * it is consistent.
    	 *
    	 * Version field updates must be kept separate.  This is because
    	 * kvm_write_guest_cached might use a "rep movs" instruction, and
    	 * writes within a string instruction are weakly ordered.  So there
    	 * are three writes overall.
    	 *
    	 * As a small optimization, only write the version field in the first
    	 * and third write.  The vcpu->pv_time cache is still valid, because the
    	 * version field is the first in the struct.
    	 */
    	BUILD_BUG_ON(offsetof(struct pvclock_vcpu_time_info, version) != 0);
    
    	if (guest_hv_clock.version & 1)
    		++guest_hv_clock.version;  /* first time write, random junk */
    
    	vcpu->hv_clock.version = guest_hv_clock.version + 1;
    	kvm_write_guest_cached(v->kvm, &vcpu->pv_time,
    				&vcpu->hv_clock,
    				sizeof(vcpu->hv_clock.version));
    
    	smp_wmb();
    
    	/* retain PVCLOCK_GUEST_STOPPED if set in guest copy */
    	vcpu->hv_clock.flags |= (guest_hv_clock.flags & PVCLOCK_GUEST_STOPPED);
    
    	if (vcpu->pvclock_set_guest_stopped_request) {
    		vcpu->hv_clock.flags |= PVCLOCK_GUEST_STOPPED;
    		vcpu->pvclock_set_guest_stopped_request = false;
    	}
    
    	trace_kvm_pvclock_update(v->vcpu_id, &vcpu->hv_clock);
    
    	kvm_write_guest_cached(v->kvm, &vcpu->pv_time,
    				&vcpu->hv_clock,
    				sizeof(vcpu->hv_clock));
    
    	smp_wmb();
    
    	vcpu->hv_clock.version++;
    	kvm_write_guest_cached(v->kvm, &vcpu->pv_time,
    				&vcpu->hv_clock,
    				sizeof(vcpu->hv_clock.version));
    }
    
    static int kvm_guest_time_update(struct kvm_vcpu *v)
    {
    	unsigned long flags, tgt_tsc_khz;
    	struct kvm_vcpu_arch *vcpu = &v->arch;
    	struct kvm_arch *ka = &v->kvm->arch;
    	s64 kernel_ns;
    	u64 tsc_timestamp, host_tsc;
    	u8 pvclock_flags;
    	bool use_master_clock;
    
    	kernel_ns = 0;
    	host_tsc = 0;
    
    	/*
    	 * If the host uses TSC clock, then passthrough TSC as stable
    	 * to the guest.
    	 */
    	spin_lock(&ka->pvclock_gtod_sync_lock);
    	use_master_clock = ka->use_master_clock;
    	if (use_master_clock) {
    		host_tsc = ka->master_cycle_now;
    		kernel_ns = ka->master_kernel_ns;
    	}
    	spin_unlock(&ka->pvclock_gtod_sync_lock);
    
    	/* Keep irq disabled to prevent changes to the clock */
    	local_irq_save(flags);
    	tgt_tsc_khz = __this_cpu_read(cpu_tsc_khz);
    	if (unlikely(tgt_tsc_khz == 0)) {
    		local_irq_restore(flags);
    		kvm_make_request(KVM_REQ_CLOCK_UPDATE, v);
    		return 1;
    	}
    	if (!use_master_clock) {
    		host_tsc = rdtsc();
    		kernel_ns = ktime_get_boot_ns();
    	}
    
    	tsc_timestamp = kvm_read_l1_tsc(v, host_tsc);
    
    	/*
    	 * We may have to catch up the TSC to match elapsed wall clock
    	 * time for two reasons, even if kvmclock is used.
    	 *   1) CPU could have been running below the maximum TSC rate
    	 *   2) Broken TSC compensation resets the base at each VCPU
    	 *      entry to avoid unknown leaps of TSC even when running
    	 *      again on the same CPU.  This may cause apparent elapsed
    	 *      time to disappear, and the guest to stand still or run
    	 *	very slowly.
    	 */
    	if (vcpu->tsc_catchup) {
    		u64 tsc = compute_guest_tsc(v, kernel_ns);
    		if (tsc > tsc_timestamp) {
    			adjust_tsc_offset_guest(v, tsc - tsc_timestamp);
    			tsc_timestamp = tsc;
    		}
    	}
    
    	local_irq_restore(flags);
    
    	/* With all the info we got, fill in the values */
    
    	if (kvm_has_tsc_control)
    		tgt_tsc_khz = kvm_scale_tsc(v, tgt_tsc_khz);
    
    	if (unlikely(vcpu->hw_tsc_khz != tgt_tsc_khz)) {
    		kvm_get_time_scale(NSEC_PER_SEC, tgt_tsc_khz * 1000LL,
    				   &vcpu->hv_clock.tsc_shift,
    				   &vcpu->hv_clock.tsc_to_system_mul);
    		vcpu->hw_tsc_khz = tgt_tsc_khz;
    	}
    
    	vcpu->hv_clock.tsc_timestamp = tsc_timestamp;
    	vcpu->hv_clock.system_time = kernel_ns + v->kvm->arch.kvmclock_offset;
    	vcpu->last_guest_tsc = tsc_timestamp;
    
    	/* If the host uses TSC clocksource, then it is stable */
    	pvclock_flags = 0;
    	if (use_master_clock)
    		pvclock_flags |= PVCLOCK_TSC_STABLE_BIT;
    
    	vcpu->hv_clock.flags = pvclock_flags;
    
    	if (vcpu->pv_time_enabled)
    		kvm_setup_pvclock_page(v);
    	if (v == kvm_get_vcpu(v->kvm, 0))
    		kvm_hv_setup_tsc_page(v->kvm, &vcpu->hv_clock);
    	return 0;
    }
    
    /*
     * kvmclock updates which are isolated to a given vcpu, such as
     * vcpu->cpu migration, should not allow system_timestamp from
     * the rest of the vcpus to remain static. Otherwise ntp frequency
     * correction applies to one vcpu's system_timestamp but not
     * the others.
     *
     * So in those cases, request a kvmclock update for all vcpus.
     * We need to rate-limit these requests though, as they can
     * considerably slow guests that have a large number of vcpus.
     * The time for a remote vcpu to update its kvmclock is bound
     * by the delay we use to rate-limit the updates.
     */
    
    #define KVMCLOCK_UPDATE_DELAY msecs_to_jiffies(100)
    
    static void kvmclock_update_fn(struct work_struct *work)
    {
    	int i;
    	struct delayed_work *dwork = to_delayed_work(work);
    	struct kvm_arch *ka = container_of(dwork, struct kvm_arch,
    					   kvmclock_update_work);
    	struct kvm *kvm = container_of(ka, struct kvm, arch);
    	struct kvm_vcpu *vcpu;
    
    	kvm_for_each_vcpu(i, vcpu, kvm) {
    		kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
    		kvm_vcpu_kick(vcpu);
    	}
    }
    
    static void kvm_gen_kvmclock_update(struct kvm_vcpu *v)
    {
    	struct kvm *kvm = v->kvm;
    
    	kvm_make_request(KVM_REQ_CLOCK_UPDATE, v);
    	schedule_delayed_work(&kvm->arch.kvmclock_update_work,
    					KVMCLOCK_UPDATE_DELAY);
    }
    
    #define KVMCLOCK_SYNC_PERIOD (300 * HZ)
    
    static void kvmclock_sync_fn(struct work_struct *work)
    {
    	struct delayed_work *dwork = to_delayed_work(work);
    	struct kvm_arch *ka = container_of(dwork, struct kvm_arch,
    					   kvmclock_sync_work);
    	struct kvm *kvm = container_of(ka, struct kvm, arch);
    
    	if (!kvmclock_periodic_sync)
    		return;
    
    	schedule_delayed_work(&kvm->arch.kvmclock_update_work, 0);
    	schedule_delayed_work(&kvm->arch.kvmclock_sync_work,
    					KVMCLOCK_SYNC_PERIOD);
    }
    
    static int set_msr_mce(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
    {
    	u64 mcg_cap = vcpu->arch.mcg_cap;
    	unsigned bank_num = mcg_cap & 0xff;
    	u32 msr = msr_info->index;
    	u64 data = msr_info->data;
    
    	switch (msr) {
    	case MSR_IA32_MCG_STATUS:
    		vcpu->arch.mcg_status = data;
    		break;
    	case MSR_IA32_MCG_CTL:
    		if (!(mcg_cap & MCG_CTL_P) &&
    		    (data || !msr_info->host_initiated))
    			return 1;
    		if (data != 0 && data != ~(u64)0)
    			return 1;
    		vcpu->arch.mcg_ctl = data;
    		break;
    	default:
    		if (msr >= MSR_IA32_MC0_CTL &&
    		    msr < MSR_IA32_MCx_CTL(bank_num)) {
    			u32 offset = msr - MSR_IA32_MC0_CTL;
    			/* only 0 or all 1s can be written to IA32_MCi_CTL
    			 * some Linux kernels though clear bit 10 in bank 4 to
    			 * workaround a BIOS/GART TBL issue on AMD K8s, ignore
    			 * this to avoid an uncatched #GP in the guest
    			 */
    			if ((offset & 0x3) == 0 &&
    			    data != 0 && (data | (1 << 10)) != ~(u64)0)
    				return -1;
    			if (!msr_info->host_initiated &&
    				(offset & 0x3) == 1 && data != 0)
    				return -1;
    			vcpu->arch.mce_banks[offset] = data;
    			break;
    		}
    		return 1;
    	}
    	return 0;
    }
    
    static int xen_hvm_config(struct kvm_vcpu *vcpu, u64 data)
    {
    	struct kvm *kvm = vcpu->kvm;
    	int lm = is_long_mode(vcpu);
    	u8 *blob_addr = lm ? (u8 *)(long)kvm->arch.xen_hvm_config.blob_addr_64
    		: (u8 *)(long)kvm->arch.xen_hvm_config.blob_addr_32;
    	u8 blob_size = lm ? kvm->arch.xen_hvm_config.blob_size_64
    		: kvm->arch.xen_hvm_config.blob_size_32;
    	u32 page_num = data & ~PAGE_MASK;
    	u64 page_addr = data & PAGE_MASK;
    	u8 *page;
    	int r;
    
    	r = -E2BIG;
    	if (page_num >= blob_size)
    		goto out;
    	r = -ENOMEM;
    	page = memdup_user(blob_addr + (page_num * PAGE_SIZE), PAGE_SIZE);
    	if (IS_ERR(page)) {
    		r = PTR_ERR(page);
    		goto out;
    	}
    	if (kvm_vcpu_write_guest(vcpu, page_addr, page, PAGE_SIZE))
    		goto out_free;
    	r = 0;
    out_free:
    	kfree(page);
    out:
    	return r;
    }
    
    static int kvm_pv_enable_async_pf(struct kvm_vcpu *vcpu, u64 data)
    {
    	gpa_t gpa = data & ~0x3f;
    
    	/* Bits 3:5 are reserved, Should be zero */
    	if (data & 0x38)
    		return 1;
    
    	vcpu->arch.apf.msr_val = data;
    
    	if (!(data & KVM_ASYNC_PF_ENABLED)) {
    		kvm_clear_async_pf_completion_queue(vcpu);
    		kvm_async_pf_hash_reset(vcpu);
    		return 0;
    	}
    
    	if (kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.apf.data, gpa,
    					sizeof(u32)))
    		return 1;
    
    	vcpu->arch.apf.send_user_only = !(data & KVM_ASYNC_PF_SEND_ALWAYS);
    	vcpu->arch.apf.delivery_as_pf_vmexit = data & KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT;
    	kvm_async_pf_wakeup_all(vcpu);
    	return 0;
    }
    
    static void kvmclock_reset(struct kvm_vcpu *vcpu)
    {
    	vcpu->arch.pv_time_enabled = false;
    }
    
    static void kvm_vcpu_flush_tlb(struct kvm_vcpu *vcpu, bool invalidate_gpa)
    {
    	++vcpu->stat.tlb_flush;
    	kvm_x86_ops->tlb_flush(vcpu, invalidate_gpa);
    }
    
    static void record_steal_time(struct kvm_vcpu *vcpu)
    {
    	if (!(vcpu->arch.st.msr_val & KVM_MSR_ENABLED))
    		return;
    
    	if (unlikely(kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
    		&vcpu->arch.st.steal, sizeof(struct kvm_steal_time))))
    		return;
    
    	/*
    	 * Doing a TLB flush here, on the guest's behalf, can avoid
    	 * expensive IPIs.
    	 */
    	if (xchg(&vcpu->arch.st.steal.preempted, 0) & KVM_VCPU_FLUSH_TLB)
    		kvm_vcpu_flush_tlb(vcpu, false);
    
    	if (vcpu->arch.st.steal.version & 1)
    		vcpu->arch.st.steal.version += 1;  /* first time write, random junk */
    
    	vcpu->arch.st.steal.version += 1;
    
    	kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
    		&vcpu->arch.st.steal, sizeof(struct kvm_steal_time));
    
    	smp_wmb();
    
    	vcpu->arch.st.steal.steal += current->sched_info.run_delay -
    		vcpu->arch.st.last_steal;
    	vcpu->arch.st.last_steal = current->sched_info.run_delay;
    
    	kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
    		&vcpu->arch.st.steal, sizeof(struct kvm_steal_time));
    
    	smp_wmb();
    
    	vcpu->arch.st.steal.version += 1;
    
    	kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.st.stime,
    		&vcpu->arch.st.steal, sizeof(struct kvm_steal_time));
    }
    
    int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
    {
    	bool pr = false;
    	u32 msr = msr_info->index;
    	u64 data = msr_info->data;
    
    	switch (msr) {
    	case MSR_AMD64_NB_CFG:
    	case MSR_IA32_UCODE_WRITE:
    	case MSR_VM_HSAVE_PA:
    	case MSR_AMD64_PATCH_LOADER:
    	case MSR_AMD64_BU_CFG2:
    	case MSR_AMD64_DC_CFG:
    		break;
    
    	case MSR_IA32_UCODE_REV:
    		if (msr_info->host_initiated)
    			vcpu->arch.microcode_version = data;
    		break;
    	case MSR_EFER:
    		return set_efer(vcpu, data);
    	case MSR_K7_HWCR:
    		data &= ~(u64)0x40;	/* ignore flush filter disable */
    		data &= ~(u64)0x100;	/* ignore ignne emulation enable */
    		data &= ~(u64)0x8;	/* ignore TLB cache disable */
    		data &= ~(u64)0x40000;  /* ignore Mc status write enable */
    		if (data != 0) {
    			vcpu_unimpl(vcpu, "unimplemented HWCR wrmsr: 0x%llx\n",
    				    data);
    			return 1;
    		}
    		break;
    	case MSR_FAM10H_MMIO_CONF_BASE:
    		if (data != 0) {
    			vcpu_unimpl(vcpu, "unimplemented MMIO_CONF_BASE wrmsr: "
    				    "0x%llx\n", data);
    			return 1;
    		}
    		break;
    	case MSR_IA32_DEBUGCTLMSR:
    		if (!data) {
    			/* We support the non-activated case already */
    			break;
    		} else if (data & ~(DEBUGCTLMSR_LBR | DEBUGCTLMSR_BTF)) {
    			/* Values other than LBR and BTF are vendor-specific,
    			   thus reserved and should throw a #GP */
    			return 1;
    		}
    		vcpu_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTLMSR 0x%llx, nop\n",
    			    __func__, data);
    		break;
    	case 0x200 ... 0x2ff:
    		return kvm_mtrr_set_msr(vcpu, msr, data);
    	case MSR_IA32_APICBASE:
    		return kvm_set_apic_base(vcpu, msr_info);
    	case APIC_BASE_MSR ... APIC_BASE_MSR + 0x3ff:
    		return kvm_x2apic_msr_write(vcpu, msr, data);
    	case MSR_IA32_TSCDEADLINE:
    		kvm_set_lapic_tscdeadline_msr(vcpu, data);
    		break;
    	case MSR_IA32_TSC_ADJUST:
    		if (guest_cpuid_has(vcpu, X86_FEATURE_TSC_ADJUST)) {
    			if (!msr_info->host_initiated) {
    				s64 adj = data - vcpu->arch.ia32_tsc_adjust_msr;
    				adjust_tsc_offset_guest(vcpu, adj);
    			}
    			vcpu->arch.ia32_tsc_adjust_msr = data;
    		}
    		break;
    	case MSR_IA32_MISC_ENABLE:
    		vcpu->arch.ia32_misc_enable_msr = data;
    		break;
    	case MSR_IA32_SMBASE:
    		if (!msr_info->host_initiated)
    			return 1;
    		vcpu->arch.smbase = data;
    		break;
    	case MSR_IA32_TSC:
    		kvm_write_tsc(vcpu, msr_info);
    		break;
    	case MSR_SMI_COUNT:
    		if (!msr_info->host_initiated)
    			return 1;
    		vcpu->arch.smi_count = data;
    		break;
    	case MSR_KVM_WALL_CLOCK_NEW:
    	case MSR_KVM_WALL_CLOCK:
    		vcpu->kvm->arch.wall_clock = data;
    		kvm_write_wall_clock(vcpu->kvm, data);
    		break;
    	case MSR_KVM_SYSTEM_TIME_NEW:
    	case MSR_KVM_SYSTEM_TIME: {
    		struct kvm_arch *ka = &vcpu->kvm->arch;
    
    		kvmclock_reset(vcpu);
    
    		if (vcpu->vcpu_id == 0 && !msr_info->host_initiated) {
    			bool tmp = (msr == MSR_KVM_SYSTEM_TIME);
    
    			if (ka->boot_vcpu_runs_old_kvmclock != tmp)
    				kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
    
    			ka->boot_vcpu_runs_old_kvmclock = tmp;
    		}
    
    		vcpu->arch.time = data;
    		kvm_make_request(KVM_REQ_GLOBAL_CLOCK_UPDATE, vcpu);
    
    		/* we verify if the enable bit is set... */
    		if (!(data & 1))
    			break;
    
    		if (kvm_gfn_to_hva_cache_init(vcpu->kvm,
    		     &vcpu->arch.pv_time, data & ~1ULL,
    		     sizeof(struct pvclock_vcpu_time_info)))
    			vcpu->arch.pv_time_enabled = false;
    		else
    			vcpu->arch.pv_time_enabled = true;
    
    		break;
    	}
    	case MSR_KVM_ASYNC_PF_EN:
    		if (kvm_pv_enable_async_pf(vcpu, data))
    			return 1;
    		break;
    	case MSR_KVM_STEAL_TIME:
    
    		if (unlikely(!sched_info_on()))
    			return 1;
    
    		if (data & KVM_STEAL_RESERVED_MASK)
    			return 1;
    
    		if (kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.st.stime,
    						data & KVM_STEAL_VALID_BITS,
    						sizeof(struct kvm_steal_time)))
    			return 1;
    
    		vcpu->arch.st.msr_val = data;
    
    		if (!(data & KVM_MSR_ENABLED))
    			break;
    
    		kvm_make_request(KVM_REQ_STEAL_UPDATE, vcpu);
    
    		break;
    	case MSR_KVM_PV_EOI_EN:
    		if (kvm_lapic_enable_pv_eoi(vcpu, data))
    			return 1;
    		break;
    
    	case MSR_IA32_MCG_CTL:
    	case MSR_IA32_MCG_STATUS:
    	case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_CTL(KVM_MAX_MCE_BANKS) - 1:
    		return set_msr_mce(vcpu, msr_info);
    
    	case MSR_K7_PERFCTR0 ... MSR_K7_PERFCTR3:
    	case MSR_P6_PERFCTR0 ... MSR_P6_PERFCTR1:
    		pr = true; /* fall through */
    	case MSR_K7_EVNTSEL0 ... MSR_K7_EVNTSEL3:
    	case MSR_P6_EVNTSEL0 ... MSR_P6_EVNTSEL1:
    		if (kvm_pmu_is_valid_msr(vcpu, msr))
    			return kvm_pmu_set_msr(vcpu, msr_info);
    
    		if (pr || data != 0)
    			vcpu_unimpl(vcpu, "disabled perfctr wrmsr: "
    				    "0x%x data 0x%llx\n", msr, data);
    		break;
    	case MSR_K7_CLK_CTL:
    		/*
    		 * Ignore all writes to this no longer documented MSR.
    		 * Writes are only relevant for old K7 processors,
    		 * all pre-dating SVM, but a recommended workaround from
    		 * AMD for these chips. It is possible to specify the
    		 * affected processor models on the command line, hence
    		 * the need to ignore the workaround.
    		 */
    		break;
    	case HV_X64_MSR_GUEST_OS_ID ... HV_X64_MSR_SINT15:
    	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
    	case HV_X64_MSR_CRASH_CTL:
    	case HV_X64_MSR_STIMER0_CONFIG ... HV_X64_MSR_STIMER3_COUNT:
    	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
    	case HV_X64_MSR_TSC_EMULATION_CONTROL:
    	case HV_X64_MSR_TSC_EMULATION_STATUS:
    		return kvm_hv_set_msr_common(vcpu, msr, data,
    					     msr_info->host_initiated);
    	case MSR_IA32_BBL_CR_CTL3:
    		/* Drop writes to this legacy MSR -- see rdmsr
    		 * counterpart for further detail.
    		 */
    		if (report_ignored_msrs)
    			vcpu_unimpl(vcpu, "ignored wrmsr: 0x%x data 0x%llx\n",
    				msr, data);
    		break;
    	case MSR_AMD64_OSVW_ID_LENGTH:
    		if (!guest_cpuid_has(vcpu, X86_FEATURE_OSVW))
    			return 1;
    		vcpu->arch.osvw.length = data;
    		break;
    	case MSR_AMD64_OSVW_STATUS:
    		if (!guest_cpuid_has(vcpu, X86_FEATURE_OSVW))
    			return 1;
    		vcpu->arch.osvw.status = data;
    		break;
    	case MSR_PLATFORM_INFO:
    		if (!msr_info->host_initiated ||
    		    (!(data & MSR_PLATFORM_INFO_CPUID_FAULT) &&
    		     cpuid_fault_enabled(vcpu)))
    			return 1;
    		vcpu->arch.msr_platform_info = data;
    		break;
    	case MSR_MISC_FEATURES_ENABLES:
    		if (data & ~MSR_MISC_FEATURES_ENABLES_CPUID_FAULT ||
    		    (data & MSR_MISC_FEATURES_ENABLES_CPUID_FAULT &&
    		     !supports_cpuid_fault(vcpu)))
    			return 1;
    		vcpu->arch.msr_misc_features_enables = data;
    		break;
    	default:
    		if (msr && (msr == vcpu->kvm->arch.xen_hvm_config.msr))
    			return xen_hvm_config(vcpu, data);
    		if (kvm_pmu_is_valid_msr(vcpu, msr))
    			return kvm_pmu_set_msr(vcpu, msr_info);
    		if (!ignore_msrs) {
    			vcpu_debug_ratelimited(vcpu, "unhandled wrmsr: 0x%x data 0x%llx\n",
    				    msr, data);
    			return 1;
    		} else {
    			if (report_ignored_msrs)
    				vcpu_unimpl(vcpu,
    					"ignored wrmsr: 0x%x data 0x%llx\n",
    					msr, data);
    			break;
    		}
    	}
    	return 0;
    }
    EXPORT_SYMBOL_GPL(kvm_set_msr_common);
    
    
    /*
     * Reads an msr value (of 'msr_index') into 'pdata'.
     * Returns 0 on success, non-0 otherwise.
     * Assumes vcpu_load() was already called.
     */
    int kvm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr)
    {
    	return kvm_x86_ops->get_msr(vcpu, msr);
    }
    EXPORT_SYMBOL_GPL(kvm_get_msr);
    
    static int get_msr_mce(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
    {
    	u64 data;
    	u64 mcg_cap = vcpu->arch.mcg_cap;
    	unsigned bank_num = mcg_cap & 0xff;
    
    	switch (msr) {
    	case MSR_IA32_P5_MC_ADDR:
    	case MSR_IA32_P5_MC_TYPE:
    		data = 0;
    		break;
    	case MSR_IA32_MCG_CAP:
    		data = vcpu->arch.mcg_cap;
    		break;
    	case MSR_IA32_MCG_CTL:
    		if (!(mcg_cap & MCG_CTL_P) && !host)
    			return 1;
    		data = vcpu->arch.mcg_ctl;
    		break;
    	case MSR_IA32_MCG_STATUS:
    		data = vcpu->arch.mcg_status;
    		break;
    	default:
    		if (msr >= MSR_IA32_MC0_CTL &&
    		    msr < MSR_IA32_MCx_CTL(bank_num)) {
    			u32 offset = msr - MSR_IA32_MC0_CTL;
    			data = vcpu->arch.mce_banks[offset];
    			break;
    		}
    		return 1;
    	}
    	*pdata = data;
    	return 0;
    }
    
    int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
    {
    	switch (msr_info->index) {
    	case MSR_IA32_PLATFORM_ID:
    	case MSR_IA32_EBL_CR_POWERON:
    	case MSR_IA32_DEBUGCTLMSR:
    	case MSR_IA32_LASTBRANCHFROMIP:
    	case MSR_IA32_LASTBRANCHTOIP:
    	case MSR_IA32_LASTINTFROMIP:
    	case MSR_IA32_LASTINTTOIP:
    	case MSR_K8_SYSCFG:
    	case MSR_K8_TSEG_ADDR:
    	case MSR_K8_TSEG_MASK:
    	case MSR_K7_HWCR:
    	case MSR_VM_HSAVE_PA:
    	case MSR_K8_INT_PENDING_MSG:
    	case MSR_AMD64_NB_CFG:
    	case MSR_FAM10H_MMIO_CONF_BASE:
    	case MSR_AMD64_BU_CFG2:
    	case MSR_IA32_PERF_CTL:
    	case MSR_AMD64_DC_CFG:
    		msr_info->data = 0;
    		break;
    	case MSR_F15H_PERF_CTL0 ... MSR_F15H_PERF_CTR5:
    	case MSR_K7_EVNTSEL0 ... MSR_K7_EVNTSEL3:
    	case MSR_K7_PERFCTR0 ... MSR_K7_PERFCTR3:
    	case MSR_P6_PERFCTR0 ... MSR_P6_PERFCTR1:
    	case MSR_P6_EVNTSEL0 ... MSR_P6_EVNTSEL1:
    		if (kvm_pmu_is_valid_msr(vcpu, msr_info->index))
    			return kvm_pmu_get_msr(vcpu, msr_info->index, &msr_info->data);
    		msr_info->data = 0;
    		break;
    	case MSR_IA32_UCODE_REV:
    		msr_info->data = vcpu->arch.microcode_version;
    		break;
    	case MSR_IA32_TSC:
    		msr_info->data = kvm_scale_tsc(vcpu, rdtsc()) + vcpu->arch.tsc_offset;
    		break;
    	case MSR_MTRRcap:
    	case 0x200 ... 0x2ff:
    		return kvm_mtrr_get_msr(vcpu, msr_info->index, &msr_info->data);
    	case 0xcd: /* fsb frequency */
    		msr_info->data = 3;
    		break;
    		/*
    		 * MSR_EBC_FREQUENCY_ID
    		 * Conservative value valid for even the basic CPU models.
    		 * Models 0,1: 000 in bits 23:21 indicating a bus speed of
    		 * 100MHz, model 2 000 in bits 18:16 indicating 100MHz,
    		 * and 266MHz for model 3, or 4. Set Core Clock
    		 * Frequency to System Bus Frequency Ratio to 1 (bits
    		 * 31:24) even though these are only valid for CPU
    		 * models > 2, however guests may end up dividing or
    		 * multiplying by zero otherwise.
    		 */
    	case MSR_EBC_FREQUENCY_ID:
    		msr_info->data = 1 << 24;
    		break;
    	case MSR_IA32_APICBASE:
    		msr_info->data = kvm_get_apic_base(vcpu);
    		break;
    	case APIC_BASE_MSR ... APIC_BASE_MSR + 0x3ff:
    		return kvm_x2apic_msr_read(vcpu, msr_info->index, &msr_info->data);
    		break;
    	case MSR_IA32_TSCDEADLINE:
    		msr_info->data = kvm_get_lapic_tscdeadline_msr(vcpu);
    		break;
    	case MSR_IA32_TSC_ADJUST:
    		msr_info->data = (u64)vcpu->arch.ia32_tsc_adjust_msr;
    		break;
    	case MSR_IA32_MISC_ENABLE:
    		msr_info->data = vcpu->arch.ia32_misc_enable_msr;
    		break;
    	case MSR_IA32_SMBASE:
    		if (!msr_info->host_initiated)
    			return 1;
    		msr_info->data = vcpu->arch.smbase;
    		break;
    	case MSR_SMI_COUNT:
    		msr_info->data = vcpu->arch.smi_count;
    		break;
    	case MSR_IA32_PERF_STATUS:
    		/* TSC increment by tick */
    		msr_info->data = 1000ULL;
    		/* CPU multiplier */
    		msr_info->data |= (((uint64_t)4ULL) << 40);
    		break;
    	case MSR_EFER:
    		msr_info->data = vcpu->arch.efer;
    		break;
    	case MSR_KVM_WALL_CLOCK:
    	case MSR_KVM_WALL_CLOCK_NEW:
    		msr_info->data = vcpu->kvm->arch.wall_clock;
    		break;
    	case MSR_KVM_SYSTEM_TIME:
    	case MSR_KVM_SYSTEM_TIME_NEW:
    		msr_info->data = vcpu->arch.time;
    		break;
    	case MSR_KVM_ASYNC_PF_EN:
    		msr_info->data = vcpu->arch.apf.msr_val;
    		break;
    	case MSR_KVM_STEAL_TIME:
    		msr_info->data = vcpu->arch.st.msr_val;
    		break;
    	case MSR_KVM_PV_EOI_EN:
    		msr_info->data = vcpu->arch.pv_eoi.msr_val;
    		break;
    	case MSR_IA32_P5_MC_ADDR:
    	case MSR_IA32_P5_MC_TYPE:
    	case MSR_IA32_MCG_CAP:
    	case MSR_IA32_MCG_CTL:
    	case MSR_IA32_MCG_STATUS:
    	case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_CTL(KVM_MAX_MCE_BANKS) - 1:
    		return get_msr_mce(vcpu, msr_info->index, &msr_info->data,
    				   msr_info->host_initiated);
    	case MSR_K7_CLK_CTL:
    		/*
    		 * Provide expected ramp-up count for K7. All other
    		 * are set to zero, indicating minimum divisors for
    		 * every field.
    		 *
    		 * This prevents guest kernels on AMD host with CPU
    		 * type 6, model 8 and higher from exploding due to
    		 * the rdmsr failing.
    		 */
    		msr_info->data = 0x20000000;
    		break;
    	case HV_X64_MSR_GUEST_OS_ID ... HV_X64_MSR_SINT15:
    	case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
    	case HV_X64_MSR_CRASH_CTL:
    	case HV_X64_MSR_STIMER0_CONFIG ... HV_X64_MSR_STIMER3_COUNT:
    	case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
    	case HV_X64_MSR_TSC_EMULATION_CONTROL:
    	case HV_X64_MSR_TSC_EMULATION_STATUS:
    		return kvm_hv_get_msr_common(vcpu,
    					     msr_info->index, &msr_info->data,
    					     msr_info->host_initiated);
    		break;
    	case MSR_IA32_BBL_CR_CTL3:
    		/* This legacy MSR exists but isn't fully documented in current
    		 * silicon.  It is however accessed by winxp in very narrow
    		 * scenarios where it sets bit #19, itself documented as
    		 * a "reserved" bit.  Best effort attempt to source coherent
    		 * read data here should the balance of the register be
    		 * interpreted by the guest:
    		 *
    		 * L2 cache control register 3: 64GB range, 256KB size,
    		 * enabled, latency 0x1, configured
    		 */
    		msr_info->data = 0xbe702111;
    		break;
    	case MSR_AMD64_OSVW_ID_LENGTH:
    		if (!guest_cpuid_has(vcpu, X86_FEATURE_OSVW))
    			return 1;
    		msr_info->data = vcpu->arch.osvw.length;
    		break;
    	case MSR_AMD64_OSVW_STATUS:
    		if (!guest_cpuid_has(vcpu, X86_FEATURE_OSVW))
    			return 1;
    		msr_info->data = vcpu->arch.osvw.status;
    		break;
    	case MSR_PLATFORM_INFO:
    		if (!msr_info->host_initiated &&
    		    !vcpu->kvm->arch.guest_can_read_msr_platform_info)
    			return 1;
    		msr_info->data = vcpu->arch.msr_platform_info;
    		break;
    	case MSR_MISC_FEATURES_ENABLES:
    		msr_info->data = vcpu->arch.msr_misc_features_enables;
    		break;
    	default:
    		if (kvm_pmu_is_valid_msr(vcpu, msr_info->index))
    			return kvm_pmu_get_msr(vcpu, msr_info->index, &msr_info->data);
    		if (!ignore_msrs) {
    			vcpu_debug_ratelimited(vcpu, "unhandled rdmsr: 0x%x\n",
    					       msr_info->index);
    			return 1;
    		} else {
    			if (report_ignored_msrs)
    				vcpu_unimpl(vcpu, "ignored rdmsr: 0x%x\n",
    					msr_info->index);
    			msr_info->data = 0;
    		}
    		break;
    	}
    	return 0;
    }
    EXPORT_SYMBOL_GPL(kvm_get_msr_common);
    
    /*
     * Read or write a bunch of msrs. All parameters are kernel addresses.
     *
     * @return number of msrs set successfully.
     */
    static int __msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs *msrs,
    		    struct kvm_msr_entry *entries,
    		    int (*do_msr)(struct kvm_vcpu *vcpu,
    				  unsigned index, u64 *data))
    {
    	int i;
    
    	for (i = 0; i < msrs->nmsrs; ++i)
    		if (do_msr(vcpu, entries[i].index, &entries[i].data))
    			break;
    
    	return i;
    }
    
    /*
     * Read or write a bunch of msrs. Parameters are user addresses.
     *
     * @return number of msrs set successfully.
     */
    static int msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs __user *user_msrs,
    		  int (*do_msr)(struct kvm_vcpu *vcpu,
    				unsigned index, u64 *data),
    		  int writeback)
    {
    	struct kvm_msrs msrs;
    	struct kvm_msr_entry *entries;
    	int r, n;
    	unsigned size;
    
    	r = -EFAULT;
    	if (copy_from_user(&msrs, user_msrs, sizeof msrs))
    		goto out;
    
    	r = -E2BIG;
    	if (msrs.nmsrs >= MAX_IO_MSRS)
    		goto out;
    
    	size = sizeof(struct kvm_msr_entry) * msrs.nmsrs;
    	entries = memdup_user(user_msrs->entries, size);
    	if (IS_ERR(entries)) {
    		r = PTR_ERR(entries);
    		goto out;
    	}
    
    	r = n = __msr_io(vcpu, &msrs, entries, do_msr);
    	if (r < 0)
    		goto out_free;
    
    	r = -EFAULT;
    	if (writeback && copy_to_user(user_msrs->entries, entries, size))
    		goto out_free;
    
    	r = n;
    
    out_free:
    	kfree(entries);
    out:
    	return r;
    }
    
    static inline bool kvm_can_mwait_in_guest(void)
    {
    	return boot_cpu_has(X86_FEATURE_MWAIT) &&
    		!boot_cpu_has_bug(X86_BUG_MONITOR) &&
    		boot_cpu_has(X86_FEATURE_ARAT);
    }
    
    int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
    {
    	int r = 0;
    
    	switch (ext) {
    	case KVM_CAP_IRQCHIP:
    	case KVM_CAP_HLT:
    	case KVM_CAP_MMU_SHADOW_CACHE_CONTROL:
    	case KVM_CAP_SET_TSS_ADDR:
    	case KVM_CAP_EXT_CPUID:
    	case KVM_CAP_EXT_EMUL_CPUID:
    	case KVM_CAP_CLOCKSOURCE:
    	case KVM_CAP_PIT:
    	case KVM_CAP_NOP_IO_DELAY:
    	case KVM_CAP_MP_STATE:
    	case KVM_CAP_SYNC_MMU:
    	case KVM_CAP_USER_NMI:
    	case KVM_CAP_REINJECT_CONTROL:
    	case KVM_CAP_IRQ_INJECT_STATUS:
    	case KVM_CAP_IOEVENTFD:
    	case KVM_CAP_IOEVENTFD_NO_LENGTH:
    	case KVM_CAP_PIT2:
    	case KVM_CAP_PIT_STATE2:
    	case KVM_CAP_SET_IDENTITY_MAP_ADDR:
    	case KVM_CAP_XEN_HVM:
    	case KVM_CAP_VCPU_EVENTS:
    	case KVM_CAP_HYPERV:
    	case KVM_CAP_HYPERV_VAPIC:
    	case KVM_CAP_HYPERV_SPIN:
    	case KVM_CAP_HYPERV_SYNIC:
    	case KVM_CAP_HYPERV_SYNIC2:
    	case KVM_CAP_HYPERV_VP_INDEX:
    	case KVM_CAP_HYPERV_EVENTFD:
    	case KVM_CAP_HYPERV_TLBFLUSH:
    	case KVM_CAP_PCI_SEGMENT:
    	case KVM_CAP_DEBUGREGS:
    	case KVM_CAP_X86_ROBUST_SINGLESTEP:
    	case KVM_CAP_XSAVE:
    	case KVM_CAP_ASYNC_PF:
    	case KVM_CAP_GET_TSC_KHZ:
    	case KVM_CAP_KVMCLOCK_CTRL:
    	case KVM_CAP_READONLY_MEM:
    	case KVM_CAP_HYPERV_TIME:
    	case KVM_CAP_IOAPIC_POLARITY_IGNORED:
    	case KVM_CAP_TSC_DEADLINE_TIMER:
    	case KVM_CAP_ENABLE_CAP_VM:
    	case KVM_CAP_DISABLE_QUIRKS:
    	case KVM_CAP_SET_BOOT_CPU_ID:
     	case KVM_CAP_SPLIT_IRQCHIP:
    	case KVM_CAP_IMMEDIATE_EXIT:
    	case KVM_CAP_GET_MSR_FEATURES:
    	case KVM_CAP_MSR_PLATFORM_INFO:
    		r = 1;
    		break;
    	case KVM_CAP_SYNC_REGS:
    		r = KVM_SYNC_X86_VALID_FIELDS;
    		break;
    	case KVM_CAP_ADJUST_CLOCK:
    		r = KVM_CLOCK_TSC_STABLE;
    		break;
    	case KVM_CAP_X86_DISABLE_EXITS:
    		r |=  KVM_X86_DISABLE_EXITS_HLT | KVM_X86_DISABLE_EXITS_PAUSE;
    		if(kvm_can_mwait_in_guest())
    			r |= KVM_X86_DISABLE_EXITS_MWAIT;
    		break;
    	case KVM_CAP_X86_SMM:
    		/* SMBASE is usually relocated above 1M on modern chipsets,
    		 * and SMM handlers might indeed rely on 4G segment limits,
    		 * so do not report SMM to be available if real mode is
    		 * emulated via vm86 mode.  Still, do not go to great lengths
    		 * to avoid userspace's usage of the feature, because it is a
    		 * fringe case that is not enabled except via specific settings
    		 * of the module parameters.
    		 */
    		r = kvm_x86_ops->has_emulated_msr(MSR_IA32_SMBASE);
    		break;
    	case KVM_CAP_VAPIC:
    		r = !kvm_x86_ops->cpu_has_accelerated_tpr();
    		break;
    	case KVM_CAP_NR_VCPUS:
    		r = KVM_SOFT_MAX_VCPUS;
    		break;
    	case KVM_CAP_MAX_VCPUS:
    		r = KVM_MAX_VCPUS;
    		break;
    	case KVM_CAP_NR_MEMSLOTS:
    		r = KVM_USER_MEM_SLOTS;
    		break;
    	case KVM_CAP_PV_MMU:	/* obsolete */
    		r = 0;
    		break;
    	case KVM_CAP_MCE:
    		r = KVM_MAX_MCE_BANKS;
    		break;
    	case KVM_CAP_XCRS:
    		r = boot_cpu_has(X86_FEATURE_XSAVE);
    		break;
    	case KVM_CAP_TSC_CONTROL:
    		r = kvm_has_tsc_control;
    		break;
    	case KVM_CAP_X2APIC_API:
    		r = KVM_X2APIC_API_VALID_FLAGS;
    		break;
    	case KVM_CAP_NESTED_STATE:
    		r = kvm_x86_ops->get_nested_state ?
    			kvm_x86_ops->get_nested_state(NULL, 0, 0) : 0;
    		break;
    	default:
    		break;
    	}
    	return r;
    
    }
    
    long kvm_arch_dev_ioctl(struct file *filp,
    			unsigned int ioctl, unsigned long arg)
    {
    	void __user *argp = (void __user *)arg;
    	long r;
    
    	switch (ioctl) {
    	case KVM_GET_MSR_INDEX_LIST: {
    		struct kvm_msr_list __user *user_msr_list = argp;
    		struct kvm_msr_list msr_list;
    		unsigned n;
    
    		r = -EFAULT;
    		if (copy_from_user(&msr_list, user_msr_list, sizeof msr_list))
    			goto out;
    		n = msr_list.nmsrs;
    		msr_list.nmsrs = num_msrs_to_save + num_emulated_msrs;
    		if (copy_to_user(user_msr_list, &msr_list, sizeof msr_list))
    			goto out;
    		r = -E2BIG;
    		if (n < msr_list.nmsrs)
    			goto out;
    		r = -EFAULT;
    		if (copy_to_user(user_msr_list->indices, &msrs_to_save,
    				 num_msrs_to_save * sizeof(u32)))
    			goto out;
    		if (copy_to_user(user_msr_list->indices + num_msrs_to_save,
    				 &emulated_msrs,
    				 num_emulated_msrs * sizeof(u32)))
    			goto out;
    		r = 0;
    		break;
    	}
    	case KVM_GET_SUPPORTED_CPUID:
    	case KVM_GET_EMULATED_CPUID: {
    		struct kvm_cpuid2 __user *cpuid_arg = argp;
    		struct kvm_cpuid2 cpuid;
    
    		r = -EFAULT;
    		if (copy_from_user(&cpuid, cpuid_arg, sizeof cpuid))
    			goto out;
    
    		r = kvm_dev_ioctl_get_cpuid(&cpuid, cpuid_arg->entries,
    					    ioctl);
    		if (r)
    			goto out;
    
    		r = -EFAULT;
    		if (copy_to_user(cpuid_arg, &cpuid, sizeof cpuid))
    			goto out;
    		r = 0;
    		break;
    	}
    	case KVM_X86_GET_MCE_CAP_SUPPORTED: {
    		r = -EFAULT;
    		if (copy_to_user(argp, &kvm_mce_cap_supported,
    				 sizeof(kvm_mce_cap_supported)))
    			goto out;
    		r = 0;
    		break;
    	case KVM_GET_MSR_FEATURE_INDEX_LIST: {
    		struct kvm_msr_list __user *user_msr_list = argp;
    		struct kvm_msr_list msr_list;
    		unsigned int n;
    
    		r = -EFAULT;
    		if (copy_from_user(&msr_list, user_msr_list, sizeof(msr_list)))
    			goto out;
    		n = msr_list.nmsrs;
    		msr_list.nmsrs = num_msr_based_features;
    		if (copy_to_user(user_msr_list, &msr_list, sizeof(msr_list)))
    			goto out;
    		r = -E2BIG;
    		if (n < msr_list.nmsrs)
    			goto out;
    		r = -EFAULT;
    		if (copy_to_user(user_msr_list->indices, &msr_based_features,
    				 num_msr_based_features * sizeof(u32)))
    			goto out;
    		r = 0;
    		break;
    	}
    	case KVM_GET_MSRS:
    		r = msr_io(NULL, argp, do_get_msr_feature, 1);
    		break;
    	}
    	default:
    		r = -EINVAL;
    	}
    out:
    	return r;
    }
    
    static void wbinvd_ipi(void *garbage)
    {
    	wbinvd();
    }
    
    static bool need_emulate_wbinvd(struct kvm_vcpu *vcpu)
    {
    	return kvm_arch_has_noncoherent_dma(vcpu->kvm);
    }
    
    void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
    {
    	/* Address WBINVD may be executed by guest */
    	if (need_emulate_wbinvd(vcpu)) {
    		if (kvm_x86_ops->has_wbinvd_exit())
    			cpumask_set_cpu(cpu, vcpu->arch.wbinvd_dirty_mask);
    		else if (vcpu->cpu != -1 && vcpu->cpu != cpu)
    			smp_call_function_single(vcpu->cpu,
    					wbinvd_ipi, NULL, 1);
    	}
    
    	kvm_x86_ops->vcpu_load(vcpu, cpu);
    
    	/* Apply any externally detected TSC adjustments (due to suspend) */
    	if (unlikely(vcpu->arch.tsc_offset_adjustment)) {
    		adjust_tsc_offset_host(vcpu, vcpu->arch.tsc_offset_adjustment);
    		vcpu->arch.tsc_offset_adjustment = 0;
    		kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
    	}
    
    	if (unlikely(vcpu->cpu != cpu) || kvm_check_tsc_unstable()) {
    		s64 tsc_delta = !vcpu->arch.last_host_tsc ? 0 :
    				rdtsc() - vcpu->arch.last_host_tsc;
    		if (tsc_delta < 0)
    			mark_tsc_unstable("KVM discovered backwards TSC");
    
    		if (kvm_check_tsc_unstable()) {
    			u64 offset = kvm_compute_tsc_offset(vcpu,
    						vcpu->arch.last_guest_tsc);
    			kvm_vcpu_write_tsc_offset(vcpu, offset);
    			vcpu->arch.tsc_catchup = 1;
    		}
    
    		if (kvm_lapic_hv_timer_in_use(vcpu))
    			kvm_lapic_restart_hv_timer(vcpu);
    
    		/*
    		 * On a host with synchronized TSC, there is no need to update
    		 * kvmclock on vcpu->cpu migration
    		 */
    		if (!vcpu->kvm->arch.use_master_clock || vcpu->cpu == -1)
    			kvm_make_request(KVM_REQ_GLOBAL_CLOCK_UPDATE, vcpu);
    		if (vcpu->cpu != cpu)
    			kvm_make_request(KVM_REQ_MIGRATE_TIMER, vcpu);
    		vcpu->cpu = cpu;
    	}
    
    	kvm_make_request(KVM_REQ_STEAL_UPDATE, vcpu);
    }
    
    static void kvm_steal_time_set_preempted(struct kvm_vcpu *vcpu)
    {
    	if (!(vcpu->arch.st.msr_val & KVM_MSR_ENABLED))
    		return;
    
    	vcpu->arch.st.steal.preempted = KVM_VCPU_PREEMPTED;
    
    	kvm_write_guest_offset_cached(vcpu->kvm, &vcpu->arch.st.stime,
    			&vcpu->arch.st.steal.preempted,
    			offsetof(struct kvm_steal_time, preempted),
    			sizeof(vcpu->arch.st.steal.preempted));
    }
    
    void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
    {
    	int idx;
    
    	if (vcpu->preempted)
    		vcpu->arch.preempted_in_kernel = !kvm_x86_ops->get_cpl(vcpu);
    
    	/*
    	 * Disable page faults because we're in atomic context here.
    	 * kvm_write_guest_offset_cached() would call might_fault()
    	 * that relies on pagefault_disable() to tell if there's a
    	 * bug. NOTE: the write to guest memory may not go through if
    	 * during postcopy live migration or if there's heavy guest
    	 * paging.
    	 */
    	pagefault_disable();
    	/*
    	 * kvm_memslots() will be called by
    	 * kvm_write_guest_offset_cached() so take the srcu lock.
    	 */
    	idx = srcu_read_lock(&vcpu->kvm->srcu);
    	kvm_steal_time_set_preempted(vcpu);
    	srcu_read_unlock(&vcpu->kvm->srcu, idx);
    	pagefault_enable();
    	kvm_x86_ops->vcpu_put(vcpu);
    	vcpu->arch.last_host_tsc = rdtsc();
    	/*
    	 * If userspace has set any breakpoints or watchpoints, dr6 is restored
    	 * on every vmexit, but if not, we might have a stale dr6 from the
    	 * guest. do_debug expects dr6 to be cleared after it runs, do the same.
    	 */
    	set_debugreg(0, 6);
    }
    
    static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu,
    				    struct kvm_lapic_state *s)
    {
    	if (vcpu->arch.apicv_active)
    		kvm_x86_ops->sync_pir_to_irr(vcpu);
    
    	return kvm_apic_get_state(vcpu, s);
    }
    
    static int kvm_vcpu_ioctl_set_lapic(struct kvm_vcpu *vcpu,
    				    struct kvm_lapic_state *s)
    {
    	int r;
    
    	r = kvm_apic_set_state(vcpu, s);
    	if (r)
    		return r;
    	update_cr8_intercept(vcpu);
    
    	return 0;
    }
    
    static int kvm_cpu_accept_dm_intr(struct kvm_vcpu *vcpu)
    {
    	return (!lapic_in_kernel(vcpu) ||
    		kvm_apic_accept_pic_intr(vcpu));
    }
    
    /*
     * if userspace requested an interrupt window, check that the
     * interrupt window is open.
     *
     * No need to exit to userspace if we already have an interrupt queued.
     */
    static int kvm_vcpu_ready_for_interrupt_injection(struct kvm_vcpu *vcpu)
    {
    	return kvm_arch_interrupt_allowed(vcpu) &&
    		!kvm_cpu_has_interrupt(vcpu) &&
    		!kvm_event_needs_reinjection(vcpu) &&
    		kvm_cpu_accept_dm_intr(vcpu);
    }
    
    static int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
    				    struct kvm_interrupt *irq)
    {
    	if (irq->irq >= KVM_NR_INTERRUPTS)
    		return -EINVAL;
    
    	if (!irqchip_in_kernel(vcpu->kvm)) {
    		kvm_queue_interrupt(vcpu, irq->irq, false);
    		kvm_make_request(KVM_REQ_EVENT, vcpu);
    		return 0;
    	}
    
    	/*
    	 * With in-kernel LAPIC, we only use this to inject EXTINT, so
    	 * fail for in-kernel 8259.
    	 */
    	if (pic_in_kernel(vcpu->kvm))
    		return -ENXIO;
    
    	if (vcpu->arch.pending_external_vector != -1)
    		return -EEXIST;
    
    	vcpu->arch.pending_external_vector = irq->irq;
    	kvm_make_request(KVM_REQ_EVENT, vcpu);
    	return 0;
    }
    
    static int kvm_vcpu_ioctl_nmi(struct kvm_vcpu *vcpu)
    {
    	kvm_inject_nmi(vcpu);
    
    	return 0;
    }
    
    static int kvm_vcpu_ioctl_smi(struct kvm_vcpu *vcpu)
    {
    	kvm_make_request(KVM_REQ_SMI, vcpu);
    
    	return 0;
    }
    
    static int vcpu_ioctl_tpr_access_reporting(struct kvm_vcpu *vcpu,
    					   struct kvm_tpr_access_ctl *tac)
    {
    	if (tac->flags)
    		return -EINVAL;
    	vcpu->arch.tpr_access_reporting = !!tac->enabled;
    	return 0;
    }
    
    static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu,
    					u64 mcg_cap)
    {
    	int r;
    	unsigned bank_num = mcg_cap & 0xff, bank;
    
    	r = -EINVAL;
    	if (!bank_num || bank_num >= KVM_MAX_MCE_BANKS)
    		goto out;
    	if (mcg_cap & ~(kvm_mce_cap_supported | 0xff | 0xff0000))
    		goto out;
    	r = 0;
    	vcpu->arch.mcg_cap = mcg_cap;
    	/* Init IA32_MCG_CTL to all 1s */
    	if (mcg_cap & MCG_CTL_P)
    		vcpu->arch.mcg_ctl = ~(u64)0;
    	/* Init IA32_MCi_CTL to all 1s */
    	for (bank = 0; bank < bank_num; bank++)
    		vcpu->arch.mce_banks[bank*4] = ~(u64)0;
    
    	if (kvm_x86_ops->setup_mce)
    		kvm_x86_ops->setup_mce(vcpu);
    out:
    	return r;
    }
    
    static int kvm_vcpu_ioctl_x86_set_mce(struct kvm_vcpu *vcpu,
    				      struct kvm_x86_mce *mce)
    {
    	u64 mcg_cap = vcpu->arch.mcg_cap;
    	unsigned bank_num = mcg_cap & 0xff;
    	u64 *banks = vcpu->arch.mce_banks;
    
    	if (mce->bank >= bank_num || !(mce->status & MCI_STATUS_VAL))
    		return -EINVAL;
    	/*
    	 * if IA32_MCG_CTL is not all 1s, the uncorrected error
    	 * reporting is disabled
    	 */
    	if ((mce->status & MCI_STATUS_UC) && (mcg_cap & MCG_CTL_P) &&
    	    vcpu->arch.mcg_ctl != ~(u64)0)
    		return 0;
    	banks += 4 * mce->bank;
    	/*
    	 * if IA32_MCi_CTL is not all 1s, the uncorrected error
    	 * reporting is disabled for the bank
    	 */
    	if ((mce->status & MCI_STATUS_UC) && banks[0] != ~(u64)0)
    		return 0;
    	if (mce->status & MCI_STATUS_UC) {
    		if ((vcpu->arch.mcg_status & MCG_STATUS_MCIP) ||
    		    !kvm_read_cr4_bits(vcpu, X86_CR4_MCE)) {
    			kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
    			return 0;
    		}
    		if (banks[1] & MCI_STATUS_VAL)
    			mce->status |= MCI_STATUS_OVER;
    		banks[2] = mce->addr;
    		banks[3] = mce->misc;
    		vcpu->arch.mcg_status = mce->mcg_status;
    		banks[1] = mce->status;
    		kvm_queue_exception(vcpu, MC_VECTOR);
    	} else if (!(banks[1] & MCI_STATUS_VAL)
    		   || !(banks[1] & MCI_STATUS_UC)) {
    		if (banks[1] & MCI_STATUS_VAL)
    			mce->status |= MCI_STATUS_OVER;
    		banks[2] = mce->addr;
    		banks[3] = mce->misc;
    		banks[1] = mce->status;
    	} else
    		banks[1] |= MCI_STATUS_OVER;
    	return 0;
    }
    
    static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu,
    					       struct kvm_vcpu_events *events)
    {
    	process_nmi(vcpu);
    	/*
    	 * FIXME: pass injected and pending separately.  This is only
    	 * needed for nested virtualization, whose state cannot be
    	 * migrated yet.  For now we can combine them.
    	 */
    	events->exception.injected =
    		(vcpu->arch.exception.pending ||
    		 vcpu->arch.exception.injected) &&
    		!kvm_exception_is_soft(vcpu->arch.exception.nr);
    	events->exception.nr = vcpu->arch.exception.nr;
    	events->exception.has_error_code = vcpu->arch.exception.has_error_code;
    	events->exception.pad = 0;
    	events->exception.error_code = vcpu->arch.exception.error_code;
    
    	events->interrupt.injected =
    		vcpu->arch.interrupt.injected && !vcpu->arch.interrupt.soft;
    	events->interrupt.nr = vcpu->arch.interrupt.nr;
    	events->interrupt.soft = 0;
    	events->interrupt.shadow = kvm_x86_ops->get_interrupt_shadow(vcpu);
    
    	events->nmi.injected = vcpu->arch.nmi_injected;
    	events->nmi.pending = vcpu->arch.nmi_pending != 0;
    	events->nmi.masked = kvm_x86_ops->get_nmi_mask(vcpu);
    	events->nmi.pad = 0;
    
    	events->sipi_vector = 0; /* never valid when reporting to user space */
    
    	events->smi.smm = is_smm(vcpu);
    	events->smi.pending = vcpu->arch.smi_pending;
    	events->smi.smm_inside_nmi =
    		!!(vcpu->arch.hflags & HF_SMM_INSIDE_NMI_MASK);
    	events->smi.latched_init = kvm_lapic_latched_init(vcpu);
    
    	events->flags = (KVM_VCPUEVENT_VALID_NMI_PENDING
    			 | KVM_VCPUEVENT_VALID_SHADOW
    			 | KVM_VCPUEVENT_VALID_SMM);
    	memset(&events->reserved, 0, sizeof(events->reserved));
    }
    
    static void kvm_set_hflags(struct kvm_vcpu *vcpu, unsigned emul_flags);
    
    static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu,
    					      struct kvm_vcpu_events *events)
    {
    	if (events->flags & ~(KVM_VCPUEVENT_VALID_NMI_PENDING
    			      | KVM_VCPUEVENT_VALID_SIPI_VECTOR
    			      | KVM_VCPUEVENT_VALID_SHADOW
    			      | KVM_VCPUEVENT_VALID_SMM))
    		return -EINVAL;
    
    	if (events->exception.injected &&
    	    (events->exception.nr > 31 || events->exception.nr == NMI_VECTOR ||
    	     is_guest_mode(vcpu)))
    		return -EINVAL;
    
    	/* INITs are latched while in SMM */
    	if (events->flags & KVM_VCPUEVENT_VALID_SMM &&
    	    (events->smi.smm || events->smi.pending) &&
    	    vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED)
    		return -EINVAL;
    
    	process_nmi(vcpu);
    	vcpu->arch.exception.injected = false;
    	vcpu->arch.exception.pending = events->exception.injected;
    	vcpu->arch.exception.nr = events->exception.nr;
    	vcpu->arch.exception.has_error_code = events->exception.has_error_code;
    	vcpu->arch.exception.error_code = events->exception.error_code;
    
    	vcpu->arch.interrupt.injected = events->interrupt.injected;
    	vcpu->arch.interrupt.nr = events->interrupt.nr;
    	vcpu->arch.interrupt.soft = events->interrupt.soft;
    	if (events->flags & KVM_VCPUEVENT_VALID_SHADOW)
    		kvm_x86_ops->set_interrupt_shadow(vcpu,
    						  events->interrupt.shadow);
    
    	vcpu->arch.nmi_injected = events->nmi.injected;
    	if (events->flags & KVM_VCPUEVENT_VALID_NMI_PENDING)
    		vcpu->arch.nmi_pending = events->nmi.pending;
    	kvm_x86_ops->set_nmi_mask(vcpu, events->nmi.masked);
    
    	if (events->flags & KVM_VCPUEVENT_VALID_SIPI_VECTOR &&
    	    lapic_in_kernel(vcpu))
    		vcpu->arch.apic->sipi_vector = events->sipi_vector;
    
    	if (events->flags & KVM_VCPUEVENT_VALID_SMM) {
    		u32 hflags = vcpu->arch.hflags;
    		if (events->smi.smm)
    			hflags |= HF_SMM_MASK;
    		else
    			hflags &= ~HF_SMM_MASK;
    		kvm_set_hflags(vcpu, hflags);
    
    		vcpu->arch.smi_pending = events->smi.pending;
    
    		if (events->smi.smm) {
    			if (events->smi.smm_inside_nmi)
    				vcpu->arch.hflags |= HF_SMM_INSIDE_NMI_MASK;
    			else
    				vcpu->arch.hflags &= ~HF_SMM_INSIDE_NMI_MASK;
    			if (lapic_in_kernel(vcpu)) {
    				if (events->smi.latched_init)
    					set_bit(KVM_APIC_INIT, &vcpu->arch.apic->pending_events);
    				else
    					clear_bit(KVM_APIC_INIT, &vcpu->arch.apic->pending_events);
    			}
    		}
    	}
    
    	kvm_make_request(KVM_REQ_EVENT, vcpu);
    
    	return 0;
    }
    
    static void kvm_vcpu_ioctl_x86_get_debugregs(struct kvm_vcpu *vcpu,
    					     struct kvm_debugregs *dbgregs)
    {
    	unsigned long val;
    
    	memcpy(dbgregs->db, vcpu->arch.db, sizeof(vcpu->arch.db));
    	kvm_get_dr(vcpu, 6, &val);
    	dbgregs->dr6 = val;
    	dbgregs->dr7 = vcpu->arch.dr7;
    	dbgregs->flags = 0;
    	memset(&dbgregs->reserved, 0, sizeof(dbgregs->reserved));
    }
    
    static int kvm_vcpu_ioctl_x86_set_debugregs(struct kvm_vcpu *vcpu,
    					    struct kvm_debugregs *dbgregs)
    {
    	if (dbgregs->flags)
    		return -EINVAL;
    
    	if (dbgregs->dr6 & ~0xffffffffull)
    		return -EINVAL;
    	if (dbgregs->dr7 & ~0xffffffffull)
    		return -EINVAL;
    
    	memcpy(vcpu->arch.db, dbgregs->db, sizeof(vcpu->arch.db));
    	kvm_update_dr0123(vcpu);
    	vcpu->arch.dr6 = dbgregs->dr6;
    	kvm_update_dr6(vcpu);
    	vcpu->arch.dr7 = dbgregs->dr7;
    	kvm_update_dr7(vcpu);
    
    	return 0;
    }
    
    #define XSTATE_COMPACTION_ENABLED (1ULL << 63)
    
    static void fill_xsave(u8 *dest, struct kvm_vcpu *vcpu)
    {
    	struct xregs_state *xsave = &vcpu->arch.guest_fpu.state.xsave;
    	u64 xstate_bv = xsave->header.xfeatures;
    	u64 valid;
    
    	/*
    	 * Copy legacy XSAVE area, to avoid complications with CPUID
    	 * leaves 0 and 1 in the loop below.
    	 */
    	memcpy(dest, xsave, XSAVE_HDR_OFFSET);
    
    	/* Set XSTATE_BV */
    	xstate_bv &= vcpu->arch.guest_supported_xcr0 | XFEATURE_MASK_FPSSE;
    	*(u64 *)(dest + XSAVE_HDR_OFFSET) = xstate_bv;
    
    	/*
    	 * Copy each region from the possibly compacted offset to the
    	 * non-compacted offset.
    	 */
    	valid = xstate_bv & ~XFEATURE_MASK_FPSSE;
    	while (valid) {
    		u64 feature = valid & -valid;
    		int index = fls64(feature) - 1;
    		void *src = get_xsave_addr(xsave, feature);
    
    		if (src) {
    			u32 size, offset, ecx, edx;
    			cpuid_count(XSTATE_CPUID, index,
    				    &size, &offset, &ecx, &edx);
    			if (feature == XFEATURE_MASK_PKRU)
    				memcpy(dest + offset, &vcpu->arch.pkru,
    				       sizeof(vcpu->arch.pkru));
    			else
    				memcpy(dest + offset, src, size);
    
    		}
    
    		valid -= feature;
    	}
    }
    
    static void load_xsave(struct kvm_vcpu *vcpu, u8 *src)
    {
    	struct xregs_state *xsave = &vcpu->arch.guest_fpu.state.xsave;
    	u64 xstate_bv = *(u64 *)(src + XSAVE_HDR_OFFSET);
    	u64 valid;
    
    	/*
    	 * Copy legacy XSAVE area, to avoid complications with CPUID
    	 * leaves 0 and 1 in the loop below.
    	 */
    	memcpy(xsave, src, XSAVE_HDR_OFFSET);
    
    	/* Set XSTATE_BV and possibly XCOMP_BV.  */
    	xsave->header.xfeatures = xstate_bv;
    	if (boot_cpu_has(X86_FEATURE_XSAVES))
    		xsave->header.xcomp_bv = host_xcr0 | XSTATE_COMPACTION_ENABLED;
    
    	/*
    	 * Copy each region from the non-compacted offset to the
    	 * possibly compacted offset.
    	 */
    	valid = xstate_bv & ~XFEATURE_MASK_FPSSE;
    	while (valid) {
    		u64 feature = valid & -valid;
    		int index = fls64(feature) - 1;
    		void *dest = get_xsave_addr(xsave, feature);
    
    		if (dest) {
    			u32 size, offset, ecx, edx;
    			cpuid_count(XSTATE_CPUID, index,
    				    &size, &offset, &ecx, &edx);
    			if (feature == XFEATURE_MASK_PKRU)
    				memcpy(&vcpu->arch.pkru, src + offset,
    				       sizeof(vcpu->arch.pkru));
    			else
    				memcpy(dest, src + offset, size);
    		}
    
    		valid -= feature;
    	}
    }
    
    static void kvm_vcpu_ioctl_x86_get_xsave(struct kvm_vcpu *vcpu,
    					 struct kvm_xsave *guest_xsave)
    {
    	if (boot_cpu_has(X86_FEATURE_XSAVE)) {
    		memset(guest_xsave, 0, sizeof(struct kvm_xsave));
    		fill_xsave((u8 *) guest_xsave->region, vcpu);
    	} else {
    		memcpy(guest_xsave->region,
    			&vcpu->arch.guest_fpu.state.fxsave,
    			sizeof(struct fxregs_state));
    		*(u64 *)&guest_xsave->region[XSAVE_HDR_OFFSET / sizeof(u32)] =
    			XFEATURE_MASK_FPSSE;
    	}
    }
    
    #define XSAVE_MXCSR_OFFSET 24
    
    static int kvm_vcpu_ioctl_x86_set_xsave(struct kvm_vcpu *vcpu,
    					struct kvm_xsave *guest_xsave)
    {
    	u64 xstate_bv =
    		*(u64 *)&guest_xsave->region[XSAVE_HDR_OFFSET / sizeof(u32)];
    	u32 mxcsr = *(u32 *)&guest_xsave->region[XSAVE_MXCSR_OFFSET / sizeof(u32)];
    
    	if (boot_cpu_has(X86_FEATURE_XSAVE)) {
    		/*
    		 * Here we allow setting states that are not present in
    		 * CPUID leaf 0xD, index 0, EDX:EAX.  This is for compatibility
    		 * with old userspace.
    		 */
    		if (xstate_bv & ~kvm_supported_xcr0() ||
    			mxcsr & ~mxcsr_feature_mask)
    			return -EINVAL;
    		load_xsave(vcpu, (u8 *)guest_xsave->region);
    	} else {
    		if (xstate_bv & ~XFEATURE_MASK_FPSSE ||
    			mxcsr & ~mxcsr_feature_mask)
    			return -EINVAL;
    		memcpy(&vcpu->arch.guest_fpu.state.fxsave,
    			guest_xsave->region, sizeof(struct fxregs_state));
    	}
    	return 0;
    }
    
    static void kvm_vcpu_ioctl_x86_get_xcrs(struct kvm_vcpu *vcpu,
    					struct kvm_xcrs *guest_xcrs)
    {
    	if (!boot_cpu_has(X86_FEATURE_XSAVE)) {
    		guest_xcrs->nr_xcrs = 0;
    		return;
    	}
    
    	guest_xcrs->nr_xcrs = 1;
    	guest_xcrs->flags = 0;
    	guest_xcrs->xcrs[0].xcr = XCR_XFEATURE_ENABLED_MASK;
    	guest_xcrs->xcrs[0].value = vcpu->arch.xcr0;
    }
    
    static int kvm_vcpu_ioctl_x86_set_xcrs(struct kvm_vcpu *vcpu,
    				       struct kvm_xcrs *guest_xcrs)
    {
    	int i, r = 0;
    
    	if (!boot_cpu_has(X86_FEATURE_XSAVE))
    		return -EINVAL;
    
    	if (guest_xcrs->nr_xcrs > KVM_MAX_XCRS || guest_xcrs->flags)
    		return -EINVAL;
    
    	for (i = 0; i < guest_xcrs->nr_xcrs; i++)
    		/* Only support XCR0 currently */
    		if (guest_xcrs->xcrs[i].xcr == XCR_XFEATURE_ENABLED_MASK) {
    			r = __kvm_set_xcr(vcpu, XCR_XFEATURE_ENABLED_MASK,
    				guest_xcrs->xcrs[i].value);
    			break;
    		}
    	if (r)
    		r = -EINVAL;
    	return r;
    }
    
    /*
     * kvm_set_guest_paused() indicates to the guest kernel that it has been
     * stopped by the hypervisor.  This function will be called from the host only.
     * EINVAL is returned when the host attempts to set the flag for a guest that
     * does not support pv clocks.
     */
    static int kvm_set_guest_paused(struct kvm_vcpu *vcpu)
    {
    	if (!vcpu->arch.pv_time_enabled)
    		return -EINVAL;
    	vcpu->arch.pvclock_set_guest_stopped_request = true;
    	kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
    	return 0;
    }
    
    static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
    				     struct kvm_enable_cap *cap)
    {
    	if (cap->flags)
    		return -EINVAL;
    
    	switch (cap->cap) {
    	case KVM_CAP_HYPERV_SYNIC2:
    		if (cap->args[0])
    			return -EINVAL;
    	case KVM_CAP_HYPERV_SYNIC:
    		if (!irqchip_in_kernel(vcpu->kvm))
    			return -EINVAL;
    		return kvm_hv_activate_synic(vcpu, cap->cap ==
    					     KVM_CAP_HYPERV_SYNIC2);
    	default:
    		return -EINVAL;
    	}
    }
    
    long kvm_arch_vcpu_ioctl(struct file *filp,
    			 unsigned int ioctl, unsigned long arg)
    {
    	struct kvm_vcpu *vcpu = filp->private_data;
    	void __user *argp = (void __user *)arg;
    	int r;
    	union {
    		struct kvm_lapic_state *lapic;
    		struct kvm_xsave *xsave;
    		struct kvm_xcrs *xcrs;
    		void *buffer;
    	} u;
    
    	vcpu_load(vcpu);
    
    	u.buffer = NULL;
    	switch (ioctl) {
    	case KVM_GET_LAPIC: {
    		r = -EINVAL;
    		if (!lapic_in_kernel(vcpu))
    			goto out;
    		u.lapic = kzalloc(sizeof(struct kvm_lapic_state), GFP_KERNEL);
    
    		r = -ENOMEM;
    		if (!u.lapic)
    			goto out;
    		r = kvm_vcpu_ioctl_get_lapic(vcpu, u.lapic);
    		if (r)
    			goto out;
    		r = -EFAULT;
    		if (copy_to_user(argp, u.lapic, sizeof(struct kvm_lapic_state)))
    			goto out;
    		r = 0;
    		break;
    	}
    	case KVM_SET_LAPIC: {
    		r = -EINVAL;
    		if (!lapic_in_kernel(vcpu))
    			goto out;
    		u.lapic = memdup_user(argp, sizeof(*u.lapic));
    		if (IS_ERR(u.lapic)) {
    			r = PTR_ERR(u.lapic);
    			goto out_nofree;
    		}
    
    		r = kvm_vcpu_ioctl_set_lapic(vcpu, u.lapic);
    		break;
    	}
    	case KVM_INTERRUPT: {
    		struct kvm_interrupt irq;
    
    		r = -EFAULT;
    		if (copy_from_user(&irq, argp, sizeof irq))
    			goto out;
    		r = kvm_vcpu_ioctl_interrupt(vcpu, &irq);
    		break;
    	}
    	case KVM_NMI: {
    		r = kvm_vcpu_ioctl_nmi(vcpu);
    		break;
    	}
    	case KVM_SMI: {
    		r = kvm_vcpu_ioctl_smi(vcpu);
    		break;
    	}
    	case KVM_SET_CPUID: {
    		struct kvm_cpuid __user *cpuid_arg = argp;
    		struct kvm_cpuid cpuid;
    
    		r = -EFAULT;
    		if (copy_from_user(&cpuid, cpuid_arg, sizeof cpuid))
    			goto out;
    		r = kvm_vcpu_ioctl_set_cpuid(vcpu, &cpuid, cpuid_arg->entries);
    		break;
    	}
    	case KVM_SET_CPUID2: {
    		struct kvm_cpuid2 __user *cpuid_arg = argp;
    		struct kvm_cpuid2 cpuid;
    
    		r = -EFAULT;
    		if (copy_from_user(&cpuid, cpuid_arg, sizeof cpuid))
    			goto out;
    		r = kvm_vcpu_ioctl_set_cpuid2(vcpu, &cpuid,
    					      cpuid_arg->entries);
    		break;
    	}
    	case KVM_GET_CPUID2: {
    		struct kvm_cpuid2 __user *cpuid_arg = argp;
    		struct kvm_cpuid2 cpuid;
    
    		r = -EFAULT;
    		if (copy_from_user(&cpuid, cpuid_arg, sizeof cpuid))
    			goto out;
    		r = kvm_vcpu_ioctl_get_cpuid2(vcpu, &cpuid,
    					      cpuid_arg->entries);
    		if (r)
    			goto out;
    		r = -EFAULT;
    		if (copy_to_user(cpuid_arg, &cpuid, sizeof cpuid))
    			goto out;
    		r = 0;
    		break;
    	}
    	case KVM_GET_MSRS: {
    		int idx = srcu_read_lock(&vcpu->kvm->srcu);
    		r = msr_io(vcpu, argp, do_get_msr, 1);
    		srcu_read_unlock(&vcpu->kvm->srcu, idx);
    		break;
    	}
    	case KVM_SET_MSRS: {
    		int idx = srcu_read_lock(&vcpu->kvm->srcu);
    		r = msr_io(vcpu, argp, do_set_msr, 0);
    		srcu_read_unlock(&vcpu->kvm->srcu, idx);
    		break;
    	}
    	case KVM_TPR_ACCESS_REPORTING: {
    		struct kvm_tpr_access_ctl tac;
    
    		r = -EFAULT;
    		if (copy_from_user(&tac, argp, sizeof tac))
    			goto out;
    		r = vcpu_ioctl_tpr_access_reporting(vcpu, &tac);
    		if (r)
    			goto out;
    		r = -EFAULT;
    		if (copy_to_user(argp, &tac, sizeof tac))
    			goto out;
    		r = 0;
    		break;
    	};
    	case KVM_SET_VAPIC_ADDR: {
    		struct kvm_vapic_addr va;
    		int idx;
    
    		r = -EINVAL;
    		if (!lapic_in_kernel(vcpu))
    			goto out;
    		r = -EFAULT;
    		if (copy_from_user(&va, argp, sizeof va))
    			goto out;
    		idx = srcu_read_lock(&vcpu->kvm->srcu);
    		r = kvm_lapic_set_vapic_addr(vcpu, va.vapic_addr);
    		srcu_read_unlock(&vcpu->kvm->srcu, idx);
    		break;
    	}
    	case KVM_X86_SETUP_MCE: {
    		u64 mcg_cap;
    
    		r = -EFAULT;
    		if (copy_from_user(&mcg_cap, argp, sizeof mcg_cap))
    			goto out;
    		r = kvm_vcpu_ioctl_x86_setup_mce(vcpu, mcg_cap);
    		break;
    	}
    	case KVM_X86_SET_MCE: {
    		struct kvm_x86_mce mce;
    
    		r = -EFAULT;
    		if (copy_from_user(&mce, argp, sizeof mce))
    			goto out;
    		r = kvm_vcpu_ioctl_x86_set_mce(vcpu, &mce);
    		break;
    	}
    	case KVM_GET_VCPU_EVENTS: {
    		struct kvm_vcpu_events events;
    
    		kvm_vcpu_ioctl_x86_get_vcpu_events(vcpu, &events);
    
    		r = -EFAULT;
    		if (copy_to_user(argp, &events, sizeof(struct kvm_vcpu_events)))
    			break;
    		r = 0;
    		break;
    	}
    	case KVM_SET_VCPU_EVENTS: {
    		struct kvm_vcpu_events events;
    
    		r = -EFAULT;
    		if (copy_from_user(&events, argp, sizeof(struct kvm_vcpu_events)))
    			break;
    
    		r = kvm_vcpu_ioctl_x86_set_vcpu_events(vcpu, &events);
    		break;
    	}
    	case KVM_GET_DEBUGREGS: {
    		struct kvm_debugregs dbgregs;
    
    		kvm_vcpu_ioctl_x86_get_debugregs(vcpu, &dbgregs);
    
    		r = -EFAULT;
    		if (copy_to_user(argp, &dbgregs,
    				 sizeof(struct kvm_debugregs)))
    			break;
    		r = 0;
    		break;
    	}
    	case KVM_SET_DEBUGREGS: {
    		struct kvm_debugregs dbgregs;
    
    		r = -EFAULT;
    		if (copy_from_user(&dbgregs, argp,
    				   sizeof(struct kvm_debugregs)))
    			break;
    
    		r = kvm_vcpu_ioctl_x86_set_debugregs(vcpu, &dbgregs);
    		break;
    	}
    	case KVM_GET_XSAVE: {
    		u.xsave = kzalloc(sizeof(struct kvm_xsave), GFP_KERNEL);
    		r = -ENOMEM;
    		if (!u.xsave)
    			break;
    
    		kvm_vcpu_ioctl_x86_get_xsave(vcpu, u.xsave);
    
    		r = -EFAULT;
    		if (copy_to_user(argp, u.xsave, sizeof(struct kvm_xsave)))
    			break;
    		r = 0;
    		break;
    	}
    	case KVM_SET_XSAVE: {
    		u.xsave = memdup_user(argp, sizeof(*u.xsave));
    		if (IS_ERR(u.xsave)) {
    			r = PTR_ERR(u.xsave);
    			goto out_nofree;
    		}
    
    		r = kvm_vcpu_ioctl_x86_set_xsave(vcpu, u.xsave);
    		break;
    	}
    	case KVM_GET_XCRS: {
    		u.xcrs = kzalloc(sizeof(struct kvm_xcrs), GFP_KERNEL);
    		r = -ENOMEM;
    		if (!u.xcrs)
    			break;
    
    		kvm_vcpu_ioctl_x86_get_xcrs(vcpu, u.xcrs);
    
    		r = -EFAULT;
    		if (copy_to_user(argp, u.xcrs,
    				 sizeof(struct kvm_xcrs)))
    			break;
    		r = 0;
    		break;
    	}
    	case KVM_SET_XCRS: {
    		u.xcrs = memdup_user(argp, sizeof(*u.xcrs));
    		if (IS_ERR(u.xcrs)) {
    			r = PTR_ERR(u.xcrs);
    			goto out_nofree;
    		}
    
    		r = kvm_vcpu_ioctl_x86_set_xcrs(vcpu, u.xcrs);
    		break;
    	}
    	case KVM_SET_TSC_KHZ: {
    		u32 user_tsc_khz;
    
    		r = -EINVAL;
    		user_tsc_khz = (u32)arg;
    
    		if (user_tsc_khz >= kvm_max_guest_tsc_khz)
    			goto out;
    
    		if (user_tsc_khz == 0)
    			user_tsc_khz = tsc_khz;
    
    		if (!kvm_set_tsc_khz(vcpu, user_tsc_khz))
    			r = 0;
    
    		goto out;
    	}
    	case KVM_GET_TSC_KHZ: {
    		r = vcpu->arch.virtual_tsc_khz;
    		goto out;
    	}
    	case KVM_KVMCLOCK_CTRL: {
    		r = kvm_set_guest_paused(vcpu);
    		goto out;
    	}
    	case KVM_ENABLE_CAP: {
    		struct kvm_enable_cap cap;
    
    		r = -EFAULT;
    		if (copy_from_user(&cap, argp, sizeof(cap)))
    			goto out;
    		r = kvm_vcpu_ioctl_enable_cap(vcpu, &cap);
    		break;
    	}
    	case KVM_GET_NESTED_STATE: {
    		struct kvm_nested_state __user *user_kvm_nested_state = argp;
    		u32 user_data_size;
    
    		r = -EINVAL;
    		if (!kvm_x86_ops->get_nested_state)
    			break;
    
    		BUILD_BUG_ON(sizeof(user_data_size) != sizeof(user_kvm_nested_state->size));
    		if (get_user(user_data_size, &user_kvm_nested_state->size))
    			return -EFAULT;
    
    		r = kvm_x86_ops->get_nested_state(vcpu, user_kvm_nested_state,
    						  user_data_size);
    		if (r < 0)
    			return r;
    
    		if (r > user_data_size) {
    			if (put_user(r, &user_kvm_nested_state->size))
    				return -EFAULT;
    			return -E2BIG;
    		}
    		r = 0;
    		break;
    	}
    	case KVM_SET_NESTED_STATE: {
    		struct kvm_nested_state __user *user_kvm_nested_state = argp;
    		struct kvm_nested_state kvm_state;
    
    		r = -EINVAL;
    		if (!kvm_x86_ops->set_nested_state)
    			break;
    
    		if (copy_from_user(&kvm_state, user_kvm_nested_state, sizeof(kvm_state)))
    			return -EFAULT;
    
    		if (kvm_state.size < sizeof(kvm_state))
    			return -EINVAL;
    
    		if (kvm_state.flags &
    		    ~(KVM_STATE_NESTED_RUN_PENDING | KVM_STATE_NESTED_GUEST_MODE))
    			return -EINVAL;
    
    		/* nested_run_pending implies guest_mode.  */
    		if (kvm_state.flags == KVM_STATE_NESTED_RUN_PENDING)
    			return -EINVAL;
    
    		r = kvm_x86_ops->set_nested_state(vcpu, user_kvm_nested_state, &kvm_state);
    		break;
    	}
    	default:
    		r = -EINVAL;
    	}
    out:
    	kfree(u.buffer);
    out_nofree:
    	vcpu_put(vcpu);
    	return r;
    }
    
    vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
    {
    	return VM_FAULT_SIGBUS;
    }
    
    static int kvm_vm_ioctl_set_tss_addr(struct kvm *kvm, unsigned long addr)
    {
    	int ret;
    
    	if (addr > (unsigned int)(-3 * PAGE_SIZE))
    		return -EINVAL;
    	ret = kvm_x86_ops->set_tss_addr(kvm, addr);
    	return ret;
    }
    
    static int kvm_vm_ioctl_set_identity_map_addr(struct kvm *kvm,
    					      u64 ident_addr)
    {
    	return kvm_x86_ops->set_identity_map_addr(kvm, ident_addr);
    }
    
    static int kvm_vm_ioctl_set_nr_mmu_pages(struct kvm *kvm,
    					  u32 kvm_nr_mmu_pages)
    {
    	if (kvm_nr_mmu_pages < KVM_MIN_ALLOC_MMU_PAGES)
    		return -EINVAL;
    
    	mutex_lock(&kvm->slots_lock);
    
    	kvm_mmu_change_mmu_pages(kvm, kvm_nr_mmu_pages);
    	kvm->arch.n_requested_mmu_pages = kvm_nr_mmu_pages;
    
    	mutex_unlock(&kvm->slots_lock);
    	return 0;
    }
    
    static int kvm_vm_ioctl_get_nr_mmu_pages(struct kvm *kvm)
    {
    	return kvm->arch.n_max_mmu_pages;
    }
    
    static int kvm_vm_ioctl_get_irqchip(struct kvm *kvm, struct kvm_irqchip *chip)
    {
    	struct kvm_pic *pic = kvm->arch.vpic;
    	int r;
    
    	r = 0;
    	switch (chip->chip_id) {
    	case KVM_IRQCHIP_PIC_MASTER:
    		memcpy(&chip->chip.pic, &pic->pics[0],
    			sizeof(struct kvm_pic_state));
    		break;
    	case KVM_IRQCHIP_PIC_SLAVE:
    		memcpy(&chip->chip.pic, &pic->pics[1],
    			sizeof(struct kvm_pic_state));
    		break;
    	case KVM_IRQCHIP_IOAPIC:
    		kvm_get_ioapic(kvm, &chip->chip.ioapic);
    		break;
    	default:
    		r = -EINVAL;
    		break;
    	}
    	return r;
    }
    
    static int kvm_vm_ioctl_set_irqchip(struct kvm *kvm, struct kvm_irqchip *chip)
    {
    	struct kvm_pic *pic = kvm->arch.vpic;
    	int r;
    
    	r = 0;
    	switch (chip->chip_id) {
    	case KVM_IRQCHIP_PIC_MASTER:
    		spin_lock(&pic->lock);
    		memcpy(&pic->pics[0], &chip->chip.pic,
    			sizeof(struct kvm_pic_state));
    		spin_unlock(&pic->lock);
    		break;
    	case KVM_IRQCHIP_PIC_SLAVE:
    		spin_lock(&pic->lock);
    		memcpy(&pic->pics[1], &chip->chip.pic,
    			sizeof(struct kvm_pic_state));
    		spin_unlock(&pic->lock);
    		break;
    	case KVM_IRQCHIP_IOAPIC:
    		kvm_set_ioapic(kvm, &chip->chip.ioapic);
    		break;
    	default:
    		r = -EINVAL;
    		break;
    	}
    	kvm_pic_update_irq(pic);
    	return r;
    }
    
    static int kvm_vm_ioctl_get_pit(struct kvm *kvm, struct kvm_pit_state *ps)
    {
    	struct kvm_kpit_state *kps = &kvm->arch.vpit->pit_state;
    
    	BUILD_BUG_ON(sizeof(*ps) != sizeof(kps->channels));
    
    	mutex_lock(&kps->lock);
    	memcpy(ps, &kps->channels, sizeof(*ps));
    	mutex_unlock(&kps->lock);
    	return 0;
    }
    
    static int kvm_vm_ioctl_set_pit(struct kvm *kvm, struct kvm_pit_state *ps)
    {
    	int i;
    	struct kvm_pit *pit = kvm->arch.vpit;
    
    	mutex_lock(&pit->pit_state.lock);
    	memcpy(&pit->pit_state.channels, ps, sizeof(*ps));
    	for (i = 0; i < 3; i++)
    		kvm_pit_load_count(pit, i, ps->channels[i].count, 0);
    	mutex_unlock(&pit->pit_state.lock);
    	return 0;
    }
    
    static int kvm_vm_ioctl_get_pit2(struct kvm *kvm, struct kvm_pit_state2 *ps)
    {
    	mutex_lock(&kvm->arch.vpit->pit_state.lock);
    	memcpy(ps->channels, &kvm->arch.vpit->pit_state.channels,
    		sizeof(ps->channels));
    	ps->flags = kvm->arch.vpit->pit_state.flags;
    	mutex_unlock(&kvm->arch.vpit->pit_state.lock);
    	memset(&ps->reserved, 0, sizeof(ps->reserved));
    	return 0;
    }
    
    static int kvm_vm_ioctl_set_pit2(struct kvm *kvm, struct kvm_pit_state2 *ps)
    {
    	int start = 0;
    	int i;
    	u32 prev_legacy, cur_legacy;
    	struct kvm_pit *pit = kvm->arch.vpit;
    
    	mutex_lock(&pit->pit_state.lock);
    	prev_legacy = pit->pit_state.flags & KVM_PIT_FLAGS_HPET_LEGACY;
    	cur_legacy = ps->flags & KVM_PIT_FLAGS_HPET_LEGACY;
    	if (!prev_legacy && cur_legacy)
    		start = 1;
    	memcpy(&pit->pit_state.channels, &ps->channels,
    	       sizeof(pit->pit_state.channels));
    	pit->pit_state.flags = ps->flags;
    	for (i = 0; i < 3; i++)
    		kvm_pit_load_count(pit, i, pit->pit_state.channels[i].count,
    				   start && i == 0);
    	mutex_unlock(&pit->pit_state.lock);
    	return 0;
    }
    
    static int kvm_vm_ioctl_reinject(struct kvm *kvm,
    				 struct kvm_reinject_control *control)
    {
    	struct kvm_pit *pit = kvm->arch.vpit;
    
    	if (!pit)
    		return -ENXIO;
    
    	/* pit->pit_state.lock was overloaded to prevent userspace from getting
    	 * an inconsistent state after running multiple KVM_REINJECT_CONTROL
    	 * ioctls in parallel.  Use a separate lock if that ioctl isn't rare.
    	 */
    	mutex_lock(&pit->pit_state.lock);
    	kvm_pit_set_reinject(pit, control->pit_reinject);
    	mutex_unlock(&pit->pit_state.lock);
    
    	return 0;
    }
    
    /**
     * kvm_vm_ioctl_get_dirty_log - get and clear the log of dirty pages in a slot
     * @kvm: kvm instance
     * @log: slot id and address to which we copy the log
     *
     * Steps 1-4 below provide general overview of dirty page logging. See
     * kvm_get_dirty_log_protect() function description for additional details.
     *
     * We call kvm_get_dirty_log_protect() to handle steps 1-3, upon return we
     * always flush the TLB (step 4) even if previous step failed  and the dirty
     * bitmap may be corrupt. Regardless of previous outcome the KVM logging API
     * does not preclude user space subsequent dirty log read. Flushing TLB ensures
     * writes will be marked dirty for next log read.
     *
     *   1. Take a snapshot of the bit and clear it if needed.
     *   2. Write protect the corresponding page.
     *   3. Copy the snapshot to the userspace.
     *   4. Flush TLB's if needed.
     */
    int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
    {
    	bool is_dirty = false;
    	int r;
    
    	mutex_lock(&kvm->slots_lock);
    
    	/*
    	 * Flush potentially hardware-cached dirty pages to dirty_bitmap.
    	 */
    	if (kvm_x86_ops->flush_log_dirty)
    		kvm_x86_ops->flush_log_dirty(kvm);
    
    	r = kvm_get_dirty_log_protect(kvm, log, &is_dirty);
    
    	/*
    	 * All the TLBs can be flushed out of mmu lock, see the comments in
    	 * kvm_mmu_slot_remove_write_access().
    	 */
    	lockdep_assert_held(&kvm->slots_lock);
    	if (is_dirty)
    		kvm_flush_remote_tlbs(kvm);
    
    	mutex_unlock(&kvm->slots_lock);
    	return r;
    }
    
    int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_event,
    			bool line_status)
    {
    	if (!irqchip_in_kernel(kvm))
    		return -ENXIO;
    
    	irq_event->status = kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID,
    					irq_event->irq, irq_event->level,
    					line_status);
    	return 0;
    }
    
    static int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
    				   struct kvm_enable_cap *cap)
    {
    	int r;
    
    	if (cap->flags)
    		return -EINVAL;
    
    	switch (cap->cap) {
    	case KVM_CAP_DISABLE_QUIRKS:
    		kvm->arch.disabled_quirks = cap->args[0];
    		r = 0;
    		break;
    	case KVM_CAP_SPLIT_IRQCHIP: {
    		mutex_lock(&kvm->lock);
    		r = -EINVAL;
    		if (cap->args[0] > MAX_NR_RESERVED_IOAPIC_PINS)
    			goto split_irqchip_unlock;
    		r = -EEXIST;
    		if (irqchip_in_kernel(kvm))
    			goto split_irqchip_unlock;
    		if (kvm->created_vcpus)
    			goto split_irqchip_unlock;
    		r = kvm_setup_empty_irq_routing(kvm);
    		if (r)
    			goto split_irqchip_unlock;
    		/* Pairs with irqchip_in_kernel. */
    		smp_wmb();
    		kvm->arch.irqchip_mode = KVM_IRQCHIP_SPLIT;
    		kvm->arch.nr_reserved_ioapic_pins = cap->args[0];
    		r = 0;
    split_irqchip_unlock:
    		mutex_unlock(&kvm->lock);
    		break;
    	}
    	case KVM_CAP_X2APIC_API:
    		r = -EINVAL;
    		if (cap->args[0] & ~KVM_X2APIC_API_VALID_FLAGS)
    			break;
    
    		if (cap->args[0] & KVM_X2APIC_API_USE_32BIT_IDS)
    			kvm->arch.x2apic_format = true;
    		if (cap->args[0] & KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK)
    			kvm->arch.x2apic_broadcast_quirk_disabled = true;
    
    		r = 0;
    		break;
    	case KVM_CAP_X86_DISABLE_EXITS:
    		r = -EINVAL;
    		if (cap->args[0] & ~KVM_X86_DISABLE_VALID_EXITS)
    			break;
    
    		if ((cap->args[0] & KVM_X86_DISABLE_EXITS_MWAIT) &&
    			kvm_can_mwait_in_guest())
    			kvm->arch.mwait_in_guest = true;
    		if (cap->args[0] & KVM_X86_DISABLE_EXITS_HLT)
    			kvm->arch.hlt_in_guest = true;
    		if (cap->args[0] & KVM_X86_DISABLE_EXITS_PAUSE)
    			kvm->arch.pause_in_guest = true;
    		r = 0;
    		break;
    	case KVM_CAP_MSR_PLATFORM_INFO:
    		kvm->arch.guest_can_read_msr_platform_info = cap->args[0];
    		r = 0;
    		break;
    	default:
    		r = -EINVAL;
    		break;
    	}
    	return r;
    }
    
    long kvm_arch_vm_ioctl(struct file *filp,
    		       unsigned int ioctl, unsigned long arg)
    {
    	struct kvm *kvm = filp->private_data;
    	void __user *argp = (void __user *)arg;
    	int r = -ENOTTY;
    	/*
    	 * This union makes it completely explicit to gcc-3.x
    	 * that these two variables' stack usage should be
    	 * combined, not added together.
    	 */
    	union {
    		struct kvm_pit_state ps;
    		struct kvm_pit_state2 ps2;
    		struct kvm_pit_config pit_config;
    	} u;
    
    	switch (ioctl) {
    	case KVM_SET_TSS_ADDR:
    		r = kvm_vm_ioctl_set_tss_addr(kvm, arg);
    		break;
    	case KVM_SET_IDENTITY_MAP_ADDR: {
    		u64 ident_addr;
    
    		mutex_lock(&kvm->lock);
    		r = -EINVAL;
    		if (kvm->created_vcpus)
    			goto set_identity_unlock;
    		r = -EFAULT;
    		if (copy_from_user(&ident_addr, argp, sizeof ident_addr))
    			goto set_identity_unlock;
    		r = kvm_vm_ioctl_set_identity_map_addr(kvm, ident_addr);
    set_identity_unlock:
    		mutex_unlock(&kvm->lock);
    		break;
    	}
    	case KVM_SET_NR_MMU_PAGES:
    		r = kvm_vm_ioctl_set_nr_mmu_pages(kvm, arg);
    		break;
    	case KVM_GET_NR_MMU_PAGES:
    		r = kvm_vm_ioctl_get_nr_mmu_pages(kvm);
    		break;
    	case KVM_CREATE_IRQCHIP: {
    		mutex_lock(&kvm->lock);
    
    		r = -EEXIST;
    		if (irqchip_in_kernel(kvm))
    			goto create_irqchip_unlock;
    
    		r = -EINVAL;
    		if (kvm->created_vcpus)
    			goto create_irqchip_unlock;
    
    		r = kvm_pic_init(kvm);
    		if (r)
    			goto create_irqchip_unlock;
    
    		r = kvm_ioapic_init(kvm);
    		if (r) {
    			kvm_pic_destroy(kvm);
    			goto create_irqchip_unlock;
    		}
    
    		r = kvm_setup_default_irq_routing(kvm);
    		if (r) {
    			kvm_ioapic_destroy(kvm);
    			kvm_pic_destroy(kvm);
    			goto create_irqchip_unlock;
    		}
    		/* Write kvm->irq_routing before enabling irqchip_in_kernel. */
    		smp_wmb();
    		kvm->arch.irqchip_mode = KVM_IRQCHIP_KERNEL;
    	create_irqchip_unlock:
    		mutex_unlock(&kvm->lock);
    		break;
    	}
    	case KVM_CREATE_PIT:
    		u.pit_config.flags = KVM_PIT_SPEAKER_DUMMY;
    		goto create_pit;
    	case KVM_CREATE_PIT2:
    		r = -EFAULT;
    		if (copy_from_user(&u.pit_config, argp,
    				   sizeof(struct kvm_pit_config)))
    			goto out;
    	create_pit:
    		mutex_lock(&kvm->lock);
    		r = -EEXIST;
    		if (kvm->arch.vpit)
    			goto create_pit_unlock;
    		r = -ENOMEM;
    		kvm->arch.vpit = kvm_create_pit(kvm, u.pit_config.flags);
    		if (kvm->arch.vpit)
    			r = 0;
    	create_pit_unlock:
    		mutex_unlock(&kvm->lock);
    		break;
    	case KVM_GET_IRQCHIP: {
    		/* 0: PIC master, 1: PIC slave, 2: IOAPIC */
    		struct kvm_irqchip *chip;
    
    		chip = memdup_user(argp, sizeof(*chip));
    		if (IS_ERR(chip)) {
    			r = PTR_ERR(chip);
    			goto out;
    		}
    
    		r = -ENXIO;
    		if (!irqchip_kernel(kvm))
    			goto get_irqchip_out;
    		r = kvm_vm_ioctl_get_irqchip(kvm, chip);
    		if (r)
    			goto get_irqchip_out;
    		r = -EFAULT;
    		if (copy_to_user(argp, chip, sizeof *chip))
    			goto get_irqchip_out;
    		r = 0;
    	get_irqchip_out:
    		kfree(chip);
    		break;
    	}
    	case KVM_SET_IRQCHIP: {
    		/* 0: PIC master, 1: PIC slave, 2: IOAPIC */
    		struct kvm_irqchip *chip;
    
    		chip = memdup_user(argp, sizeof(*chip));
    		if (IS_ERR(chip)) {
    			r = PTR_ERR(chip);
    			goto out;
    		}
    
    		r = -ENXIO;
    		if (!irqchip_kernel(kvm))
    			goto set_irqchip_out;
    		r = kvm_vm_ioctl_set_irqchip(kvm, chip);
    		if (r)
    			goto set_irqchip_out;
    		r = 0;
    	set_irqchip_out:
    		kfree(chip);
    		break;
    	}
    	case KVM_GET_PIT: {
    		r = -EFAULT;
    		if (copy_from_user(&u.ps, argp, sizeof(struct kvm_pit_state)))
    			goto out;
    		r = -ENXIO;
    		if (!kvm->arch.vpit)
    			goto out;
    		r = kvm_vm_ioctl_get_pit(kvm, &u.ps);
    		if (r)
    			goto out;
    		r = -EFAULT;
    		if (copy_to_user(argp, &u.ps, sizeof(struct kvm_pit_state)))
    			goto out;
    		r = 0;
    		break;
    	}
    	case KVM_SET_PIT: {
    		r = -EFAULT;
    		if (copy_from_user(&u.ps, argp, sizeof u.ps))
    			goto out;
    		r = -ENXIO;
    		if (!kvm->arch.vpit)
    			goto out;
    		r = kvm_vm_ioctl_set_pit(kvm, &u.ps);
    		break;
    	}
    	case KVM_GET_PIT2: {
    		r = -ENXIO;
    		if (!kvm->arch.vpit)
    			goto out;
    		r = kvm_vm_ioctl_get_pit2(kvm, &u.ps2);
    		if (r)
    			goto out;
    		r = -EFAULT;
    		if (copy_to_user(argp, &u.ps2, sizeof(u.ps2)))
    			goto out;
    		r = 0;
    		break;
    	}
    	case KVM_SET_PIT2: {
    		r = -EFAULT;
    		if (copy_from_user(&u.ps2, argp, sizeof(u.ps2)))
    			goto out;
    		r = -ENXIO;
    		if (!kvm->arch.vpit)
    			goto out;
    		r = kvm_vm_ioctl_set_pit2(kvm, &u.ps2);
    		break;
    	}
    	case KVM_REINJECT_CONTROL: {
    		struct kvm_reinject_control control;
    		r =  -EFAULT;
    		if (copy_from_user(&control, argp, sizeof(control)))
    			goto out;
    		r = kvm_vm_ioctl_reinject(kvm, &control);
    		break;
    	}
    	case KVM_SET_BOOT_CPU_ID:
    		r = 0;
    		mutex_lock(&kvm->lock);
    		if (kvm->created_vcpus)
    			r = -EBUSY;
    		else
    			kvm->arch.bsp_vcpu_id = arg;
    		mutex_unlock(&kvm->lock);
    		break;
    	case KVM_XEN_HVM_CONFIG: {
    		struct kvm_xen_hvm_config xhc;
    		r = -EFAULT;
    		if (copy_from_user(&xhc, argp, sizeof(xhc)))
    			goto out;
    		r = -EINVAL;
    		if (xhc.flags)
    			goto out;
    		memcpy(&kvm->arch.xen_hvm_config, &xhc, sizeof(xhc));
    		r = 0;
    		break;
    	}
    	case KVM_SET_CLOCK: {
    		struct kvm_clock_data user_ns;
    		u64 now_ns;
    
    		r = -EFAULT;
    		if (copy_from_user(&user_ns, argp, sizeof(user_ns)))
    			goto out;
    
    		r = -EINVAL;
    		if (user_ns.flags)
    			goto out;
    
    		r = 0;
    		/*
    		 * TODO: userspace has to take care of races with VCPU_RUN, so
    		 * kvm_gen_update_masterclock() can be cut down to locked
    		 * pvclock_update_vm_gtod_copy().
    		 */
    		kvm_gen_update_masterclock(kvm);
    		now_ns = get_kvmclock_ns(kvm);
    		kvm->arch.kvmclock_offset += user_ns.clock - now_ns;
    		kvm_make_all_cpus_request(kvm, KVM_REQ_CLOCK_UPDATE);
    		break;
    	}
    	case KVM_GET_CLOCK: {
    		struct kvm_clock_data user_ns;
    		u64 now_ns;
    
    		now_ns = get_kvmclock_ns(kvm);
    		user_ns.clock = now_ns;
    		user_ns.flags = kvm->arch.use_master_clock ? KVM_CLOCK_TSC_STABLE : 0;
    		memset(&user_ns.pad, 0, sizeof(user_ns.pad));
    
    		r = -EFAULT;
    		if (copy_to_user(argp, &user_ns, sizeof(user_ns)))
    			goto out;
    		r = 0;
    		break;
    	}
    	case KVM_ENABLE_CAP: {
    		struct kvm_enable_cap cap;
    
    		r = -EFAULT;
    		if (copy_from_user(&cap, argp, sizeof(cap)))
    			goto out;
    		r = kvm_vm_ioctl_enable_cap(kvm, &cap);
    		break;
    	}
    	case KVM_MEMORY_ENCRYPT_OP: {
    		r = -ENOTTY;
    		if (kvm_x86_ops->mem_enc_op)
    			r = kvm_x86_ops->mem_enc_op(kvm, argp);
    		break;
    	}
    	case KVM_MEMORY_ENCRYPT_REG_REGION: {
    		struct kvm_enc_region region;
    
    		r = -EFAULT;
    		if (copy_from_user(&region, argp, sizeof(region)))
    			goto out;
    
    		r = -ENOTTY;
    		if (kvm_x86_ops->mem_enc_reg_region)
    			r = kvm_x86_ops->mem_enc_reg_region(kvm, &region);
    		break;
    	}
    	case KVM_MEMORY_ENCRYPT_UNREG_REGION: {
    		struct kvm_enc_region region;
    
    		r = -EFAULT;
    		if (copy_from_user(&region, argp, sizeof(region)))
    			goto out;
    
    		r = -ENOTTY;
    		if (kvm_x86_ops->mem_enc_unreg_region)
    			r = kvm_x86_ops->mem_enc_unreg_region(kvm, &region);
    		break;
    	}
    	case KVM_HYPERV_EVENTFD: {
    		struct kvm_hyperv_eventfd hvevfd;
    
    		r = -EFAULT;
    		if (copy_from_user(&hvevfd, argp, sizeof(hvevfd)))
    			goto out;
    		r = kvm_vm_ioctl_hv_eventfd(kvm, &hvevfd);
    		break;
    	}
    	default:
    		r = -ENOTTY;
    	}
    out:
    	return r;
    }
    
    static void kvm_init_msr_list(void)
    {
    	u32 dummy[2];
    	unsigned i, j;
    
    	for (i = j = 0; i < ARRAY_SIZE(msrs_to_save); i++) {
    		if (rdmsr_safe(msrs_to_save[i], &dummy[0], &dummy[1]) < 0)
    			continue;
    
    		/*
    		 * Even MSRs that are valid in the host may not be exposed
    		 * to the guests in some cases.
    		 */
    		switch (msrs_to_save[i]) {
    		case MSR_IA32_BNDCFGS:
    			if (!kvm_x86_ops->mpx_supported())
    				continue;
    			break;
    		case MSR_TSC_AUX:
    			if (!kvm_x86_ops->rdtscp_supported())
    				continue;
    			break;
    		default:
    			break;
    		}
    
    		if (j < i)
    			msrs_to_save[j] = msrs_to_save[i];
    		j++;
    	}
    	num_msrs_to_save = j;
    
    	for (i = j = 0; i < ARRAY_SIZE(emulated_msrs); i++) {
    		if (!kvm_x86_ops->has_emulated_msr(emulated_msrs[i]))
    			continue;
    
    		if (j < i)
    			emulated_msrs[j] = emulated_msrs[i];
    		j++;
    	}
    	num_emulated_msrs = j;
    
    	for (i = j = 0; i < ARRAY_SIZE(msr_based_features); i++) {
    		struct kvm_msr_entry msr;
    
    		msr.index = msr_based_features[i];
    		if (kvm_get_msr_feature(&msr))
    			continue;
    
    		if (j < i)
    			msr_based_features[j] = msr_based_features[i];
    		j++;
    	}
    	num_msr_based_features = j;
    }
    
    static int vcpu_mmio_write(struct kvm_vcpu *vcpu, gpa_t addr, int len,
    			   const void *v)
    {
    	int handled = 0;
    	int n;
    
    	do {
    		n = min(len, 8);
    		if (!(lapic_in_kernel(vcpu) &&
    		      !kvm_iodevice_write(vcpu, &vcpu->arch.apic->dev, addr, n, v))
    		    && kvm_io_bus_write(vcpu, KVM_MMIO_BUS, addr, n, v))
    			break;
    		handled += n;
    		addr += n;
    		len -= n;
    		v += n;
    	} while (len);
    
    	return handled;
    }
    
    static int vcpu_mmio_read(struct kvm_vcpu *vcpu, gpa_t addr, int len, void *v)
    {
    	int handled = 0;
    	int n;
    
    	do {
    		n = min(len, 8);
    		if (!(lapic_in_kernel(vcpu) &&
    		      !kvm_iodevice_read(vcpu, &vcpu->arch.apic->dev,
    					 addr, n, v))
    		    && kvm_io_bus_read(vcpu, KVM_MMIO_BUS, addr, n, v))
    			break;
    		trace_kvm_mmio(KVM_TRACE_MMIO_READ, n, addr, v);
    		handled += n;
    		addr += n;
    		len -= n;
    		v += n;
    	} while (len);
    
    	return handled;
    }
    
    static void kvm_set_segment(struct kvm_vcpu *vcpu,
    			struct kvm_segment *var, int seg)
    {
    	kvm_x86_ops->set_segment(vcpu, var, seg);
    }
    
    void kvm_get_segment(struct kvm_vcpu *vcpu,
    		     struct kvm_segment *var, int seg)
    {
    	kvm_x86_ops->get_segment(vcpu, var, seg);
    }
    
    gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access,
    			   struct x86_exception *exception)
    {
    	gpa_t t_gpa;
    
    	BUG_ON(!mmu_is_nested(vcpu));
    
    	/* NPT walks are always user-walks */
    	access |= PFERR_USER_MASK;
    	t_gpa  = vcpu->arch.mmu.gva_to_gpa(vcpu, gpa, access, exception);
    
    	return t_gpa;
    }
    
    gpa_t kvm_mmu_gva_to_gpa_read(struct kvm_vcpu *vcpu, gva_t gva,
    			      struct x86_exception *exception)
    {
    	u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0;
    	return vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, access, exception);
    }
    
     gpa_t kvm_mmu_gva_to_gpa_fetch(struct kvm_vcpu *vcpu, gva_t gva,
    				struct x86_exception *exception)
    {
    	u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0;
    	access |= PFERR_FETCH_MASK;
    	return vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, access, exception);
    }
    
    gpa_t kvm_mmu_gva_to_gpa_write(struct kvm_vcpu *vcpu, gva_t gva,
    			       struct x86_exception *exception)
    {
    	u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0;
    	access |= PFERR_WRITE_MASK;
    	return vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, access, exception);
    }
    
    /* uses this to access any guest's mapped memory without checking CPL */
    gpa_t kvm_mmu_gva_to_gpa_system(struct kvm_vcpu *vcpu, gva_t gva,
    				struct x86_exception *exception)
    {
    	return vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, 0, exception);
    }
    
    static int kvm_read_guest_virt_helper(gva_t addr, void *val, unsigned int bytes,
    				      struct kvm_vcpu *vcpu, u32 access,
    				      struct x86_exception *exception)
    {
    	void *data = val;
    	int r = X86EMUL_CONTINUE;
    
    	while (bytes) {
    		gpa_t gpa = vcpu->arch.walk_mmu->gva_to_gpa(vcpu, addr, access,
    							    exception);
    		unsigned offset = addr & (PAGE_SIZE-1);
    		unsigned toread = min(bytes, (unsigned)PAGE_SIZE - offset);
    		int ret;
    
    		if (gpa == UNMAPPED_GVA)
    			return X86EMUL_PROPAGATE_FAULT;
    		ret = kvm_vcpu_read_guest_page(vcpu, gpa >> PAGE_SHIFT, data,
    					       offset, toread);
    		if (ret < 0) {
    			r = X86EMUL_IO_NEEDED;
    			goto out;
    		}
    
    		bytes -= toread;
    		data += toread;
    		addr += toread;
    	}
    out:
    	return r;
    }
    
    /* used for instruction fetching */
    static int kvm_fetch_guest_virt(struct x86_emulate_ctxt *ctxt,
    				gva_t addr, void *val, unsigned int bytes,
    				struct x86_exception *exception)
    {
    	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
    	u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0;
    	unsigned offset;
    	int ret;
    
    	/* Inline kvm_read_guest_virt_helper for speed.  */
    	gpa_t gpa = vcpu->arch.walk_mmu->gva_to_gpa(vcpu, addr, access|PFERR_FETCH_MASK,
    						    exception);
    	if (unlikely(gpa == UNMAPPED_GVA))
    		return X86EMUL_PROPAGATE_FAULT;
    
    	offset = addr & (PAGE_SIZE-1);
    	if (WARN_ON(offset + bytes > PAGE_SIZE))
    		bytes = (unsigned)PAGE_SIZE - offset;
    	ret = kvm_vcpu_read_guest_page(vcpu, gpa >> PAGE_SHIFT, val,
    				       offset, bytes);
    	if (unlikely(ret < 0))
    		return X86EMUL_IO_NEEDED;
    
    	return X86EMUL_CONTINUE;
    }
    
    int kvm_read_guest_virt(struct kvm_vcpu *vcpu,
    			       gva_t addr, void *val, unsigned int bytes,
    			       struct x86_exception *exception)
    {
    	u32 access = (kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0;
    
    	return kvm_read_guest_virt_helper(addr, val, bytes, vcpu, access,
    					  exception);
    }
    EXPORT_SYMBOL_GPL(kvm_read_guest_virt);
    
    static int emulator_read_std(struct x86_emulate_ctxt *ctxt,
    			     gva_t addr, void *val, unsigned int bytes,
    			     struct x86_exception *exception, bool system)
    {
    	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
    	u32 access = 0;
    
    	if (!system && kvm_x86_ops->get_cpl(vcpu) == 3)
    		access |= PFERR_USER_MASK;
    
    	return kvm_read_guest_virt_helper(addr, val, bytes, vcpu, access, exception);
    }
    
    static int kvm_read_guest_phys_system(struct x86_emulate_ctxt *ctxt,
    		unsigned long addr, void *val, unsigned int bytes)
    {
    	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
    	int r = kvm_vcpu_read_guest(vcpu, addr, val, bytes);
    
    	return r < 0 ? X86EMUL_IO_NEEDED : X86EMUL_CONTINUE;
    }
    
    static int kvm_write_guest_virt_helper(gva_t addr, void *val, unsigned int bytes,
    				      struct kvm_vcpu *vcpu, u32 access,
    				      struct x86_exception *exception)
    {
    	void *data = val;
    	int r = X86EMUL_CONTINUE;
    
    	while (bytes) {
    		gpa_t gpa =  vcpu->arch.walk_mmu->gva_to_gpa(vcpu, addr,
    							     access,
    							     exception);
    		unsigned offset = addr & (PAGE_SIZE-1);
    		unsigned towrite = min(bytes, (unsigned)PAGE_SIZE - offset);
    		int ret;
    
    		if (gpa == UNMAPPED_GVA)
    			return X86EMUL_PROPAGATE_FAULT;
    		ret = kvm_vcpu_write_guest(vcpu, gpa, data, towrite);
    		if (ret < 0) {
    			r = X86EMUL_IO_NEEDED;
    			goto out;
    		}
    
    		bytes -= towrite;
    		data += towrite;
    		addr += towrite;
    	}
    out:
    	return r;
    }
    
    static int emulator_write_std(struct x86_emulate_ctxt *ctxt, gva_t addr, void *val,
    			      unsigned int bytes, struct x86_exception *exception,
    			      bool system)
    {
    	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
    	u32 access = PFERR_WRITE_MASK;
    
    	if (!system && kvm_x86_ops->get_cpl(vcpu) == 3)
    		access |= PFERR_USER_MASK;
    
    	return kvm_write_guest_virt_helper(addr, val, bytes, vcpu,
    					   access, exception);
    }
    
    int kvm_write_guest_virt_system(struct kvm_vcpu *vcpu, gva_t addr, void *val,
    				unsigned int bytes, struct x86_exception *exception)
    {
    	/* kvm_write_guest_virt_system can pull in tons of pages. */
    	vcpu->arch.l1tf_flush_l1d = true;
    
    	return kvm_write_guest_virt_helper(addr, val, bytes, vcpu,
    					   PFERR_WRITE_MASK, exception);
    }
    EXPORT_SYMBOL_GPL(kvm_write_guest_virt_system);
    
    int handle_ud(struct kvm_vcpu *vcpu)
    {
    	int emul_type = EMULTYPE_TRAP_UD;
    	enum emulation_result er;
    	char sig[5]; /* ud2; .ascii "kvm" */
    	struct x86_exception e;
    
    	if (force_emulation_prefix &&
    	    kvm_read_guest_virt(vcpu, kvm_get_linear_rip(vcpu),
    				sig, sizeof(sig), &e) == 0 &&
    	    memcmp(sig, "\xf\xbkvm", sizeof(sig)) == 0) {
    		kvm_rip_write(vcpu, kvm_rip_read(vcpu) + sizeof(sig));
    		emul_type = 0;
    	}
    
    	er = kvm_emulate_instruction(vcpu, emul_type);
    	if (er == EMULATE_USER_EXIT)
    		return 0;
    	if (er != EMULATE_DONE)
    		kvm_queue_exception(vcpu, UD_VECTOR);
    	return 1;
    }
    EXPORT_SYMBOL_GPL(handle_ud);
    
    static int vcpu_is_mmio_gpa(struct kvm_vcpu *vcpu, unsigned long gva,
    			    gpa_t gpa, bool write)
    {
    	/* For APIC access vmexit */
    	if ((gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
    		return 1;
    
    	if (vcpu_match_mmio_gpa(vcpu, gpa)) {
    		trace_vcpu_match_mmio(gva, gpa, write, true);
    		return 1;
    	}
    
    	return 0;
    }
    
    static int vcpu_mmio_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva,
    				gpa_t *gpa, struct x86_exception *exception,
    				bool write)
    {
    	u32 access = ((kvm_x86_ops->get_cpl(vcpu) == 3) ? PFERR_USER_MASK : 0)
    		| (write ? PFERR_WRITE_MASK : 0);
    
    	/*
    	 * currently PKRU is only applied to ept enabled guest so
    	 * there is no pkey in EPT page table for L1 guest or EPT
    	 * shadow page table for L2 guest.
    	 */
    	if (vcpu_match_mmio_gva(vcpu, gva)
    	    && !permission_fault(vcpu, vcpu->arch.walk_mmu,
    				 vcpu->arch.access, 0, access)) {
    		*gpa = vcpu->arch.mmio_gfn << PAGE_SHIFT |
    					(gva & (PAGE_SIZE - 1));
    		trace_vcpu_match_mmio(gva, *gpa, write, false);
    		return 1;
    	}
    
    	*gpa = vcpu->arch.walk_mmu->gva_to_gpa(vcpu, gva, access, exception);
    
    	if (*gpa == UNMAPPED_GVA)
    		return -1;
    
    	return vcpu_is_mmio_gpa(vcpu, gva, *gpa, write);
    }
    
    int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
    			const void *val, int bytes)
    {
    	int ret;
    
    	ret = kvm_vcpu_write_guest(vcpu, gpa, val, bytes);
    	if (ret < 0)
    		return 0;
    	kvm_page_track_write(vcpu, gpa, val, bytes);
    	return 1;
    }
    
    struct read_write_emulator_ops {
    	int (*read_write_prepare)(struct kvm_vcpu *vcpu, void *val,
    				  int bytes);
    	int (*read_write_emulate)(struct kvm_vcpu *vcpu, gpa_t gpa,
    				  void *val, int bytes);
    	int (*read_write_mmio)(struct kvm_vcpu *vcpu, gpa_t gpa,
    			       int bytes, void *val);
    	int (*read_write_exit_mmio)(struct kvm_vcpu *vcpu, gpa_t gpa,
    				    void *val, int bytes);
    	bool write;
    };
    
    static int read_prepare(struct kvm_vcpu *vcpu, void *val, int bytes)
    {
    	if (vcpu->mmio_read_completed) {
    		trace_kvm_mmio(KVM_TRACE_MMIO_READ, bytes,
    			       vcpu->mmio_fragments[0].gpa, val);
    		vcpu->mmio_read_completed = 0;
    		return 1;
    	}
    
    	return 0;
    }
    
    static int read_emulate(struct kvm_vcpu *vcpu, gpa_t gpa,
    			void *val, int bytes)
    {
    	return !kvm_vcpu_read_guest(vcpu, gpa, val, bytes);
    }
    
    static int write_emulate(struct kvm_vcpu *vcpu, gpa_t gpa,
    			 void *val, int bytes)
    {
    	return emulator_write_phys(vcpu, gpa, val, bytes);
    }
    
    static int write_mmio(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes, void *val)
    {
    	trace_kvm_mmio(KVM_TRACE_MMIO_WRITE, bytes, gpa, val);
    	return vcpu_mmio_write(vcpu, gpa, bytes, val);
    }
    
    static int read_exit_mmio(struct kvm_vcpu *vcpu, gpa_t gpa,
    			  void *val, int bytes)
    {
    	trace_kvm_mmio(KVM_TRACE_MMIO_READ_UNSATISFIED, bytes, gpa, NULL);
    	return X86EMUL_IO_NEEDED;
    }
    
    static int write_exit_mmio(struct kvm_vcpu *vcpu, gpa_t gpa,
    			   void *val, int bytes)
    {
    	struct kvm_mmio_fragment *frag = &vcpu->mmio_fragments[0];
    
    	memcpy(vcpu->run->mmio.data, frag->data, min(8u, frag->len));
    	return X86EMUL_CONTINUE;
    }
    
    static const struct read_write_emulator_ops read_emultor = {
    	.read_write_prepare = read_prepare,
    	.read_write_emulate = read_emulate,
    	.read_write_mmio = vcpu_mmio_read,
    	.read_write_exit_mmio = read_exit_mmio,
    };
    
    static const struct read_write_emulator_ops write_emultor = {
    	.read_write_emulate = write_emulate,
    	.read_write_mmio = write_mmio,
    	.read_write_exit_mmio = write_exit_mmio,
    	.write = true,
    };
    
    static int emulator_read_write_onepage(unsigned long addr, void *val,
    				       unsigned int bytes,
    				       struct x86_exception *exception,
    				       struct kvm_vcpu *vcpu,
    				       const struct read_write_emulator_ops *ops)
    {
    	gpa_t gpa;
    	int handled, ret;
    	bool write = ops->write;
    	struct kvm_mmio_fragment *frag;
    	struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt;
    
    	/*
    	 * If the exit was due to a NPF we may already have a GPA.
    	 * If the GPA is present, use it to avoid the GVA to GPA table walk.
    	 * Note, this cannot be used on string operations since string
    	 * operation using rep will only have the initial GPA from the NPF
    	 * occurred.
    	 */
    	if (vcpu->arch.gpa_available &&
    	    emulator_can_use_gpa(ctxt) &&
    	    (addr & ~PAGE_MASK) == (vcpu->arch.gpa_val & ~PAGE_MASK)) {
    		gpa = vcpu->arch.gpa_val;
    		ret = vcpu_is_mmio_gpa(vcpu, addr, gpa, write);
    	} else {
    		ret = vcpu_mmio_gva_to_gpa(vcpu, addr, &gpa, exception, write);
    		if (ret < 0)
    			return X86EMUL_PROPAGATE_FAULT;
    	}
    
    	if (!ret && ops->read_write_emulate(vcpu, gpa, val, bytes))
    		return X86EMUL_CONTINUE;
    
    	/*
    	 * Is this MMIO handled locally?
    	 */
    	handled = ops->read_write_mmio(vcpu, gpa, bytes, val);
    	if (handled == bytes)
    		return X86EMUL_CONTINUE;
    
    	gpa += handled;
    	bytes -= handled;
    	val += handled;
    
    	WARN_ON(vcpu->mmio_nr_fragments >= KVM_MAX_MMIO_FRAGMENTS);
    	frag = &vcpu->mmio_fragments[vcpu->mmio_nr_fragments++];
    	frag->gpa = gpa;
    	frag->data = val;
    	frag->len = bytes;
    	return X86EMUL_CONTINUE;
    }
    
    static int emulator_read_write(struct x86_emulate_ctxt *ctxt,
    			unsigned long addr,
    			void *val, unsigned int bytes,
    			struct x86_exception *exception,
    			const struct read_write_emulator_ops *ops)
    {
    	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
    	gpa_t gpa;
    	int rc;
    
    	if (ops->read_write_prepare &&
    		  ops->read_write_prepare(vcpu, val, bytes))
    		return X86EMUL_CONTINUE;
    
    	vcpu->mmio_nr_fragments = 0;
    
    	/* Crossing a page boundary? */
    	if (((addr + bytes - 1) ^ addr) & PAGE_MASK) {
    		int now;
    
    		now = -addr & ~PAGE_MASK;
    		rc = emulator_read_write_onepage(addr, val, now, exception,
    						 vcpu, ops);
    
    		if (rc != X86EMUL_CONTINUE)
    			return rc;
    		addr += now;
    		if (ctxt->mode != X86EMUL_MODE_PROT64)
    			addr = (u32)addr;
    		val += now;
    		bytes -= now;
    	}
    
    	rc = emulator_read_write_onepage(addr, val, bytes, exception,
    					 vcpu, ops);
    	if (rc != X86EMUL_CONTINUE)
    		return rc;
    
    	if (!vcpu->mmio_nr_fragments)
    		return rc;
    
    	gpa = vcpu->mmio_fragments[0].gpa;
    
    	vcpu->mmio_needed = 1;
    	vcpu->mmio_cur_fragment = 0;
    
    	vcpu->run->mmio.len = min(8u, vcpu->mmio_fragments[0].len);
    	vcpu->run->mmio.is_write = vcpu->mmio_is_write = ops->write;
    	vcpu->run->exit_reason = KVM_EXIT_MMIO;
    	vcpu->run->mmio.phys_addr = gpa;
    
    	return ops->read_write_exit_mmio(vcpu, gpa, val, bytes);
    }
    
    static int emulator_read_emulated(struct x86_emulate_ctxt *ctxt,
    				  unsigned long addr,
    				  void *val,
    				  unsigned int bytes,
    				  struct x86_exception *exception)
    {
    	return emulator_read_write(ctxt, addr, val, bytes,
    				   exception, &read_emultor);
    }
    
    static int emulator_write_emulated(struct x86_emulate_ctxt *ctxt,
    			    unsigned long addr,
    			    const void *val,
    			    unsigned int bytes,
    			    struct x86_exception *exception)
    {
    	return emulator_read_write(ctxt, addr, (void *)val, bytes,
    				   exception, &write_emultor);
    }
    
    #define CMPXCHG_TYPE(t, ptr, old, new) \
    	(cmpxchg((t *)(ptr), *(t *)(old), *(t *)(new)) == *(t *)(old))
    
    #ifdef CONFIG_X86_64
    #  define CMPXCHG64(ptr, old, new) CMPXCHG_TYPE(u64, ptr, old, new)
    #else
    #  define CMPXCHG64(ptr, old, new) \
    	(cmpxchg64((u64 *)(ptr), *(u64 *)(old), *(u64 *)(new)) == *(u64 *)(old))
    #endif
    
    static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt,
    				     unsigned long addr,
    				     const void *old,
    				     const void *new,
    				     unsigned int bytes,
    				     struct x86_exception *exception)
    {
    	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
    	gpa_t gpa;
    	struct page *page;
    	char *kaddr;
    	bool exchanged;
    
    	/* guests cmpxchg8b have to be emulated atomically */
    	if (bytes > 8 || (bytes & (bytes - 1)))
    		goto emul_write;
    
    	gpa = kvm_mmu_gva_to_gpa_write(vcpu, addr, NULL);
    
    	if (gpa == UNMAPPED_GVA ||
    	    (gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
    		goto emul_write;
    
    	if (((gpa + bytes - 1) & PAGE_MASK) != (gpa & PAGE_MASK))
    		goto emul_write;
    
    	page = kvm_vcpu_gfn_to_page(vcpu, gpa >> PAGE_SHIFT);
    	if (is_error_page(page))
    		goto emul_write;
    
    	kaddr = kmap_atomic(page);
    	kaddr += offset_in_page(gpa);
    	switch (bytes) {
    	case 1:
    		exchanged = CMPXCHG_TYPE(u8, kaddr, old, new);
    		break;
    	case 2:
    		exchanged = CMPXCHG_TYPE(u16, kaddr, old, new);
    		break;
    	case 4:
    		exchanged = CMPXCHG_TYPE(u32, kaddr, old, new);
    		break;
    	case 8:
    		exchanged = CMPXCHG64(kaddr, old, new);
    		break;
    	default:
    		BUG();
    	}
    	kunmap_atomic(kaddr);
    	kvm_release_page_dirty(page);
    
    	if (!exchanged)
    		return X86EMUL_CMPXCHG_FAILED;
    
    	kvm_vcpu_mark_page_dirty(vcpu, gpa >> PAGE_SHIFT);
    	kvm_page_track_write(vcpu, gpa, new, bytes);
    
    	return X86EMUL_CONTINUE;
    
    emul_write:
    	printk_once(KERN_WARNING "kvm: emulating exchange as write\n");
    
    	return emulator_write_emulated(ctxt, addr, new, bytes, exception);
    }
    
    static int kernel_pio(struct kvm_vcpu *vcpu, void *pd)
    {
    	int r = 0, i;
    
    	for (i = 0; i < vcpu->arch.pio.count; i++) {
    		if (vcpu->arch.pio.in)
    			r = kvm_io_bus_read(vcpu, KVM_PIO_BUS, vcpu->arch.pio.port,
    					    vcpu->arch.pio.size, pd);
    		else
    			r = kvm_io_bus_write(vcpu, KVM_PIO_BUS,
    					     vcpu->arch.pio.port, vcpu->arch.pio.size,
    					     pd);
    		if (r)
    			break;
    		pd += vcpu->arch.pio.size;
    	}
    	return r;
    }
    
    static int emulator_pio_in_out(struct kvm_vcpu *vcpu, int size,
    			       unsigned short port, void *val,
    			       unsigned int count, bool in)
    {
    	vcpu->arch.pio.port = port;
    	vcpu->arch.pio.in = in;
    	vcpu->arch.pio.count  = count;
    	vcpu->arch.pio.size = size;
    
    	if (!kernel_pio(vcpu, vcpu->arch.pio_data)) {
    		vcpu->arch.pio.count = 0;
    		return 1;
    	}
    
    	vcpu->run->exit_reason = KVM_EXIT_IO;
    	vcpu->run->io.direction = in ? KVM_EXIT_IO_IN : KVM_EXIT_IO_OUT;
    	vcpu->run->io.size = size;
    	vcpu->run->io.data_offset = KVM_PIO_PAGE_OFFSET * PAGE_SIZE;
    	vcpu->run->io.count = count;
    	vcpu->run->io.port = port;
    
    	return 0;
    }
    
    static int emulator_pio_in_emulated(struct x86_emulate_ctxt *ctxt,
    				    int size, unsigned short port, void *val,
    				    unsigned int count)
    {
    	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
    	int ret;
    
    	if (vcpu->arch.pio.count)
    		goto data_avail;
    
    	memset(vcpu->arch.pio_data, 0, size * count);
    
    	ret = emulator_pio_in_out(vcpu, size, port, val, count, true);
    	if (ret) {
    data_avail:
    		memcpy(val, vcpu->arch.pio_data, size * count);
    		trace_kvm_pio(KVM_PIO_IN, port, size, count, vcpu->arch.pio_data);
    		vcpu->arch.pio.count = 0;
    		return 1;
    	}
    
    	return 0;
    }
    
    static int emulator_pio_out_emulated(struct x86_emulate_ctxt *ctxt,
    				     int size, unsigned short port,
    				     const void *val, unsigned int count)
    {
    	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
    
    	memcpy(vcpu->arch.pio_data, val, size * count);
    	trace_kvm_pio(KVM_PIO_OUT, port, size, count, vcpu->arch.pio_data);
    	return emulator_pio_in_out(vcpu, size, port, (void *)val, count, false);
    }
    
    static unsigned long get_segment_base(struct kvm_vcpu *vcpu, int seg)
    {
    	return kvm_x86_ops->get_segment_base(vcpu, seg);
    }
    
    static void emulator_invlpg(struct x86_emulate_ctxt *ctxt, ulong address)
    {
    	kvm_mmu_invlpg(emul_to_vcpu(ctxt), address);
    }
    
    static int kvm_emulate_wbinvd_noskip(struct kvm_vcpu *vcpu)
    {
    	if (!need_emulate_wbinvd(vcpu))
    		return X86EMUL_CONTINUE;
    
    	if (kvm_x86_ops->has_wbinvd_exit()) {
    		int cpu = get_cpu();
    
    		cpumask_set_cpu(cpu, vcpu->arch.wbinvd_dirty_mask);
    		smp_call_function_many(vcpu->arch.wbinvd_dirty_mask,
    				wbinvd_ipi, NULL, 1);
    		put_cpu();
    		cpumask_clear(vcpu->arch.wbinvd_dirty_mask);
    	} else
    		wbinvd();
    	return X86EMUL_CONTINUE;
    }
    
    int kvm_emulate_wbinvd(struct kvm_vcpu *vcpu)
    {
    	kvm_emulate_wbinvd_noskip(vcpu);
    	return kvm_skip_emulated_instruction(vcpu);
    }
    EXPORT_SYMBOL_GPL(kvm_emulate_wbinvd);
    
    
    
    static void emulator_wbinvd(struct x86_emulate_ctxt *ctxt)
    {
    	kvm_emulate_wbinvd_noskip(emul_to_vcpu(ctxt));
    }
    
    static int emulator_get_dr(struct x86_emulate_ctxt *ctxt, int dr,
    			   unsigned long *dest)
    {
    	return kvm_get_dr(emul_to_vcpu(ctxt), dr, dest);
    }
    
    static int emulator_set_dr(struct x86_emulate_ctxt *ctxt, int dr,
    			   unsigned long value)
    {
    
    	return __kvm_set_dr(emul_to_vcpu(ctxt), dr, value);
    }
    
    static u64 mk_cr_64(u64 curr_cr, u32 new_val)
    {
    	return (curr_cr & ~((1ULL << 32) - 1)) | new_val;
    }
    
    static unsigned long emulator_get_cr(struct x86_emulate_ctxt *ctxt, int cr)
    {
    	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
    	unsigned long value;
    
    	switch (cr) {
    	case 0:
    		value = kvm_read_cr0(vcpu);
    		break;
    	case 2:
    		value = vcpu->arch.cr2;
    		break;
    	case 3:
    		value = kvm_read_cr3(vcpu);
    		break;
    	case 4:
    		value = kvm_read_cr4(vcpu);
    		break;
    	case 8:
    		value = kvm_get_cr8(vcpu);
    		break;
    	default:
    		kvm_err("%s: unexpected cr %u\n", __func__, cr);
    		return 0;
    	}
    
    	return value;
    }
    
    static int emulator_set_cr(struct x86_emulate_ctxt *ctxt, int cr, ulong val)
    {
    	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
    	int res = 0;
    
    	switch (cr) {
    	case 0:
    		res = kvm_set_cr0(vcpu, mk_cr_64(kvm_read_cr0(vcpu), val));
    		break;
    	case 2:
    		vcpu->arch.cr2 = val;
    		break;
    	case 3:
    		res = kvm_set_cr3(vcpu, val);
    		break;
    	case 4:
    		res = kvm_set_cr4(vcpu, mk_cr_64(kvm_read_cr4(vcpu), val));
    		break;
    	case 8:
    		res = kvm_set_cr8(vcpu, val);
    		break;
    	default:
    		kvm_err("%s: unexpected cr %u\n", __func__, cr);
    		res = -1;
    	}
    
    	return res;
    }
    
    static int emulator_get_cpl(struct x86_emulate_ctxt *ctxt)
    {
    	return kvm_x86_ops->get_cpl(emul_to_vcpu(ctxt));
    }
    
    static void emulator_get_gdt(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt)
    {
    	kvm_x86_ops->get_gdt(emul_to_vcpu(ctxt), dt);
    }
    
    static void emulator_get_idt(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt)
    {
    	kvm_x86_ops->get_idt(emul_to_vcpu(ctxt), dt);
    }
    
    static void emulator_set_gdt(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt)
    {
    	kvm_x86_ops->set_gdt(emul_to_vcpu(ctxt), dt);
    }
    
    static void emulator_set_idt(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt)
    {
    	kvm_x86_ops->set_idt(emul_to_vcpu(ctxt), dt);
    }
    
    static unsigned long emulator_get_cached_segment_base(
    	struct x86_emulate_ctxt *ctxt, int seg)
    {
    	return get_segment_base(emul_to_vcpu(ctxt), seg);
    }
    
    static bool emulator_get_segment(struct x86_emulate_ctxt *ctxt, u16 *selector,
    				 struct desc_struct *desc, u32 *base3,
    				 int seg)
    {
    	struct kvm_segment var;
    
    	kvm_get_segment(emul_to_vcpu(ctxt), &var, seg);
    	*selector = var.selector;
    
    	if (var.unusable) {
    		memset(desc, 0, sizeof(*desc));
    		if (base3)
    			*base3 = 0;
    		return false;
    	}
    
    	if (var.g)
    		var.limit >>= 12;
    	set_desc_limit(desc, var.limit);
    	set_desc_base(desc, (unsigned long)var.base);
    #ifdef CONFIG_X86_64
    	if (base3)
    		*base3 = var.base >> 32;
    #endif
    	desc->type = var.type;
    	desc->s = var.s;
    	desc->dpl = var.dpl;
    	desc->p = var.present;
    	desc->avl = var.avl;
    	desc->l = var.l;
    	desc->d = var.db;
    	desc->g = var.g;
    
    	return true;
    }
    
    static void emulator_set_segment(struct x86_emulate_ctxt *ctxt, u16 selector,
    				 struct desc_struct *desc, u32 base3,
    				 int seg)
    {
    	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
    	struct kvm_segment var;
    
    	var.selector = selector;
    	var.base = get_desc_base(desc);
    #ifdef CONFIG_X86_64
    	var.base |= ((u64)base3) << 32;
    #endif
    	var.limit = get_desc_limit(desc);
    	if (desc->g)
    		var.limit = (var.limit << 12) | 0xfff;
    	var.type = desc->type;
    	var.dpl = desc->dpl;
    	var.db = desc->d;
    	var.s = desc->s;
    	var.l = desc->l;
    	var.g = desc->g;
    	var.avl = desc->avl;
    	var.present = desc->p;
    	var.unusable = !var.present;
    	var.padding = 0;
    
    	kvm_set_segment(vcpu, &var, seg);
    	return;
    }
    
    static int emulator_get_msr(struct x86_emulate_ctxt *ctxt,
    			    u32 msr_index, u64 *pdata)
    {
    	struct msr_data msr;
    	int r;
    
    	msr.index = msr_index;
    	msr.host_initiated = false;
    	r = kvm_get_msr(emul_to_vcpu(ctxt), &msr);
    	if (r)
    		return r;
    
    	*pdata = msr.data;
    	return 0;
    }
    
    static int emulator_set_msr(struct x86_emulate_ctxt *ctxt,
    			    u32 msr_index, u64 data)
    {
    	struct msr_data msr;
    
    	msr.data = data;
    	msr.index = msr_index;
    	msr.host_initiated = false;
    	return kvm_set_msr(emul_to_vcpu(ctxt), &msr);
    }
    
    static u64 emulator_get_smbase(struct x86_emulate_ctxt *ctxt)
    {
    	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
    
    	return vcpu->arch.smbase;
    }
    
    static void emulator_set_smbase(struct x86_emulate_ctxt *ctxt, u64 smbase)
    {
    	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
    
    	vcpu->arch.smbase = smbase;
    }
    
    static int emulator_check_pmc(struct x86_emulate_ctxt *ctxt,
    			      u32 pmc)
    {
    	return kvm_pmu_is_valid_msr_idx(emul_to_vcpu(ctxt), pmc);
    }
    
    static int emulator_read_pmc(struct x86_emulate_ctxt *ctxt,
    			     u32 pmc, u64 *pdata)
    {
    	return kvm_pmu_rdpmc(emul_to_vcpu(ctxt), pmc, pdata);
    }
    
    static void emulator_halt(struct x86_emulate_ctxt *ctxt)
    {
    	emul_to_vcpu(ctxt)->arch.halt_request = 1;
    }
    
    static int emulator_intercept(struct x86_emulate_ctxt *ctxt,
    			      struct x86_instruction_info *info,
    			      enum x86_intercept_stage stage)
    {
    	return kvm_x86_ops->check_intercept(emul_to_vcpu(ctxt), info, stage);
    }
    
    static bool emulator_get_cpuid(struct x86_emulate_ctxt *ctxt,
    			u32 *eax, u32 *ebx, u32 *ecx, u32 *edx, bool check_limit)
    {
    	return kvm_cpuid(emul_to_vcpu(ctxt), eax, ebx, ecx, edx, check_limit);
    }
    
    static ulong emulator_read_gpr(struct x86_emulate_ctxt *ctxt, unsigned reg)
    {
    	return kvm_register_read(emul_to_vcpu(ctxt), reg);
    }
    
    static void emulator_write_gpr(struct x86_emulate_ctxt *ctxt, unsigned reg, ulong val)
    {
    	kvm_register_write(emul_to_vcpu(ctxt), reg, val);
    }
    
    static void emulator_set_nmi_mask(struct x86_emulate_ctxt *ctxt, bool masked)
    {
    	kvm_x86_ops->set_nmi_mask(emul_to_vcpu(ctxt), masked);
    }
    
    static unsigned emulator_get_hflags(struct x86_emulate_ctxt *ctxt)
    {
    	return emul_to_vcpu(ctxt)->arch.hflags;
    }
    
    static void emulator_set_hflags(struct x86_emulate_ctxt *ctxt, unsigned emul_flags)
    {
    	kvm_set_hflags(emul_to_vcpu(ctxt), emul_flags);
    }
    
    static int emulator_pre_leave_smm(struct x86_emulate_ctxt *ctxt, u64 smbase)
    {
    	return kvm_x86_ops->pre_leave_smm(emul_to_vcpu(ctxt), smbase);
    }
    
    static const struct x86_emulate_ops emulate_ops = {
    	.read_gpr            = emulator_read_gpr,
    	.write_gpr           = emulator_write_gpr,
    	.read_std            = emulator_read_std,
    	.write_std           = emulator_write_std,
    	.read_phys           = kvm_read_guest_phys_system,
    	.fetch               = kvm_fetch_guest_virt,
    	.read_emulated       = emulator_read_emulated,
    	.write_emulated      = emulator_write_emulated,
    	.cmpxchg_emulated    = emulator_cmpxchg_emulated,
    	.invlpg              = emulator_invlpg,
    	.pio_in_emulated     = emulator_pio_in_emulated,
    	.pio_out_emulated    = emulator_pio_out_emulated,
    	.get_segment         = emulator_get_segment,
    	.set_segment         = emulator_set_segment,
    	.get_cached_segment_base = emulator_get_cached_segment_base,
    	.get_gdt             = emulator_get_gdt,
    	.get_idt	     = emulator_get_idt,
    	.set_gdt             = emulator_set_gdt,
    	.set_idt	     = emulator_set_idt,
    	.get_cr              = emulator_get_cr,
    	.set_cr              = emulator_set_cr,
    	.cpl                 = emulator_get_cpl,
    	.get_dr              = emulator_get_dr,
    	.set_dr              = emulator_set_dr,
    	.get_smbase          = emulator_get_smbase,
    	.set_smbase          = emulator_set_smbase,
    	.set_msr             = emulator_set_msr,
    	.get_msr             = emulator_get_msr,
    	.check_pmc	     = emulator_check_pmc,
    	.read_pmc            = emulator_read_pmc,
    	.halt                = emulator_halt,
    	.wbinvd              = emulator_wbinvd,
    	.fix_hypercall       = emulator_fix_hypercall,
    	.intercept           = emulator_intercept,
    	.get_cpuid           = emulator_get_cpuid,
    	.set_nmi_mask        = emulator_set_nmi_mask,
    	.get_hflags          = emulator_get_hflags,
    	.set_hflags          = emulator_set_hflags,
    	.pre_leave_smm       = emulator_pre_leave_smm,
    };
    
    static void toggle_interruptibility(struct kvm_vcpu *vcpu, u32 mask)
    {
    	u32 int_shadow = kvm_x86_ops->get_interrupt_shadow(vcpu);
    	/*
    	 * an sti; sti; sequence only disable interrupts for the first
    	 * instruction. So, if the last instruction, be it emulated or
    	 * not, left the system with the INT_STI flag enabled, it
    	 * means that the last instruction is an sti. We should not
    	 * leave the flag on in this case. The same goes for mov ss
    	 */
    	if (int_shadow & mask)
    		mask = 0;
    	if (unlikely(int_shadow || mask)) {
    		kvm_x86_ops->set_interrupt_shadow(vcpu, mask);
    		if (!mask)
    			kvm_make_request(KVM_REQ_EVENT, vcpu);
    	}
    }
    
    static bool inject_emulated_exception(struct kvm_vcpu *vcpu)
    {
    	struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt;
    	if (ctxt->exception.vector == PF_VECTOR)
    		return kvm_propagate_fault(vcpu, &ctxt->exception);
    
    	if (ctxt->exception.error_code_valid)
    		kvm_queue_exception_e(vcpu, ctxt->exception.vector,
    				      ctxt->exception.error_code);
    	else
    		kvm_queue_exception(vcpu, ctxt->exception.vector);
    	return false;
    }
    
    static void init_emulate_ctxt(struct kvm_vcpu *vcpu)
    {
    	struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt;
    	int cs_db, cs_l;
    
    	kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);
    
    	ctxt->eflags = kvm_get_rflags(vcpu);
    	ctxt->tf = (ctxt->eflags & X86_EFLAGS_TF) != 0;
    
    	ctxt->eip = kvm_rip_read(vcpu);
    	ctxt->mode = (!is_protmode(vcpu))		? X86EMUL_MODE_REAL :
    		     (ctxt->eflags & X86_EFLAGS_VM)	? X86EMUL_MODE_VM86 :
    		     (cs_l && is_long_mode(vcpu))	? X86EMUL_MODE_PROT64 :
    		     cs_db				? X86EMUL_MODE_PROT32 :
    							  X86EMUL_MODE_PROT16;
    	BUILD_BUG_ON(HF_GUEST_MASK != X86EMUL_GUEST_MASK);
    	BUILD_BUG_ON(HF_SMM_MASK != X86EMUL_SMM_MASK);
    	BUILD_BUG_ON(HF_SMM_INSIDE_NMI_MASK != X86EMUL_SMM_INSIDE_NMI_MASK);
    
    	init_decode_cache(ctxt);
    	vcpu->arch.emulate_regs_need_sync_from_vcpu = false;
    }
    
    int kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip)
    {
    	struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt;
    	int ret;
    
    	init_emulate_ctxt(vcpu);
    
    	ctxt->op_bytes = 2;
    	ctxt->ad_bytes = 2;
    	ctxt->_eip = ctxt->eip + inc_eip;
    	ret = emulate_int_real(ctxt, irq);
    
    	if (ret != X86EMUL_CONTINUE)
    		return EMULATE_FAIL;
    
    	ctxt->eip = ctxt->_eip;
    	kvm_rip_write(vcpu, ctxt->eip);
    	kvm_set_rflags(vcpu, ctxt->eflags);
    
    	return EMULATE_DONE;
    }
    EXPORT_SYMBOL_GPL(kvm_inject_realmode_interrupt);
    
    static int handle_emulation_failure(struct kvm_vcpu *vcpu, int emulation_type)
    {
    	int r = EMULATE_DONE;
    
    	++vcpu->stat.insn_emulation_fail;
    	trace_kvm_emulate_insn_failed(vcpu);
    
    	if (emulation_type & EMULTYPE_NO_UD_ON_FAIL)
    		return EMULATE_FAIL;
    
    	if (!is_guest_mode(vcpu) && kvm_x86_ops->get_cpl(vcpu) == 0) {
    		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
    		vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION;
    		vcpu->run->internal.ndata = 0;
    		r = EMULATE_USER_EXIT;
    	}
    
    	kvm_queue_exception(vcpu, UD_VECTOR);
    
    	return r;
    }
    
    static bool reexecute_instruction(struct kvm_vcpu *vcpu, gva_t cr2,
    				  bool write_fault_to_shadow_pgtable,
    				  int emulation_type)
    {
    	gpa_t gpa = cr2;
    	kvm_pfn_t pfn;
    
    	if (!(emulation_type & EMULTYPE_ALLOW_RETRY))
    		return false;
    
    	if (WARN_ON_ONCE(is_guest_mode(vcpu)))
    		return false;
    
    	if (!vcpu->arch.mmu.direct_map) {
    		/*
    		 * Write permission should be allowed since only
    		 * write access need to be emulated.
    		 */
    		gpa = kvm_mmu_gva_to_gpa_write(vcpu, cr2, NULL);
    
    		/*
    		 * If the mapping is invalid in guest, let cpu retry
    		 * it to generate fault.
    		 */
    		if (gpa == UNMAPPED_GVA)
    			return true;
    	}
    
    	/*
    	 * Do not retry the unhandleable instruction if it faults on the
    	 * readonly host memory, otherwise it will goto a infinite loop:
    	 * retry instruction -> write #PF -> emulation fail -> retry
    	 * instruction -> ...
    	 */
    	pfn = gfn_to_pfn(vcpu->kvm, gpa_to_gfn(gpa));
    
    	/*
    	 * If the instruction failed on the error pfn, it can not be fixed,
    	 * report the error to userspace.
    	 */
    	if (is_error_noslot_pfn(pfn))
    		return false;
    
    	kvm_release_pfn_clean(pfn);
    
    	/* The instructions are well-emulated on direct mmu. */
    	if (vcpu->arch.mmu.direct_map) {
    		unsigned int indirect_shadow_pages;
    
    		spin_lock(&vcpu->kvm->mmu_lock);
    		indirect_shadow_pages = vcpu->kvm->arch.indirect_shadow_pages;
    		spin_unlock(&vcpu->kvm->mmu_lock);
    
    		if (indirect_shadow_pages)
    			kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(gpa));
    
    		return true;
    	}
    
    	/*
    	 * if emulation was due to access to shadowed page table
    	 * and it failed try to unshadow page and re-enter the
    	 * guest to let CPU execute the instruction.
    	 */
    	kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(gpa));
    
    	/*
    	 * If the access faults on its page table, it can not
    	 * be fixed by unprotecting shadow page and it should
    	 * be reported to userspace.
    	 */
    	return !write_fault_to_shadow_pgtable;
    }
    
    static bool retry_instruction(struct x86_emulate_ctxt *ctxt,
    			      unsigned long cr2,  int emulation_type)
    {
    	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
    	unsigned long last_retry_eip, last_retry_addr, gpa = cr2;
    
    	last_retry_eip = vcpu->arch.last_retry_eip;
    	last_retry_addr = vcpu->arch.last_retry_addr;
    
    	/*
    	 * If the emulation is caused by #PF and it is non-page_table
    	 * writing instruction, it means the VM-EXIT is caused by shadow
    	 * page protected, we can zap the shadow page and retry this
    	 * instruction directly.
    	 *
    	 * Note: if the guest uses a non-page-table modifying instruction
    	 * on the PDE that points to the instruction, then we will unmap
    	 * the instruction and go to an infinite loop. So, we cache the
    	 * last retried eip and the last fault address, if we meet the eip
    	 * and the address again, we can break out of the potential infinite
    	 * loop.
    	 */
    	vcpu->arch.last_retry_eip = vcpu->arch.last_retry_addr = 0;
    
    	if (!(emulation_type & EMULTYPE_ALLOW_RETRY))
    		return false;
    
    	if (WARN_ON_ONCE(is_guest_mode(vcpu)))
    		return false;
    
    	if (x86_page_table_writing_insn(ctxt))
    		return false;
    
    	if (ctxt->eip == last_retry_eip && last_retry_addr == cr2)
    		return false;
    
    	vcpu->arch.last_retry_eip = ctxt->eip;
    	vcpu->arch.last_retry_addr = cr2;
    
    	if (!vcpu->arch.mmu.direct_map)
    		gpa = kvm_mmu_gva_to_gpa_write(vcpu, cr2, NULL);
    
    	kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(gpa));
    
    	return true;
    }
    
    static int complete_emulated_mmio(struct kvm_vcpu *vcpu);
    static int complete_emulated_pio(struct kvm_vcpu *vcpu);
    
    static void kvm_smm_changed(struct kvm_vcpu *vcpu)
    {
    	if (!(vcpu->arch.hflags & HF_SMM_MASK)) {
    		/* This is a good place to trace that we are exiting SMM.  */
    		trace_kvm_enter_smm(vcpu->vcpu_id, vcpu->arch.smbase, false);
    
    		/* Process a latched INIT or SMI, if any.  */
    		kvm_make_request(KVM_REQ_EVENT, vcpu);
    	}
    
    	kvm_mmu_reset_context(vcpu);
    }
    
    static void kvm_set_hflags(struct kvm_vcpu *vcpu, unsigned emul_flags)
    {
    	unsigned changed = vcpu->arch.hflags ^ emul_flags;
    
    	vcpu->arch.hflags = emul_flags;
    
    	if (changed & HF_SMM_MASK)
    		kvm_smm_changed(vcpu);
    }
    
    static int kvm_vcpu_check_hw_bp(unsigned long addr, u32 type, u32 dr7,
    				unsigned long *db)
    {
    	u32 dr6 = 0;
    	int i;
    	u32 enable, rwlen;
    
    	enable = dr7;
    	rwlen = dr7 >> 16;
    	for (i = 0; i < 4; i++, enable >>= 2, rwlen >>= 4)
    		if ((enable & 3) && (rwlen & 15) == type && db[i] == addr)
    			dr6 |= (1 << i);
    	return dr6;
    }
    
    static void kvm_vcpu_do_singlestep(struct kvm_vcpu *vcpu, int *r)
    {
    	struct kvm_run *kvm_run = vcpu->run;
    
    	if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) {
    		kvm_run->debug.arch.dr6 = DR6_BS | DR6_FIXED_1 | DR6_RTM;
    		kvm_run->debug.arch.pc = vcpu->arch.singlestep_rip;
    		kvm_run->debug.arch.exception = DB_VECTOR;
    		kvm_run->exit_reason = KVM_EXIT_DEBUG;
    		*r = EMULATE_USER_EXIT;
    	} else {
    		/*
    		 * "Certain debug exceptions may clear bit 0-3.  The
    		 * remaining contents of the DR6 register are never
    		 * cleared by the processor".
    		 */
    		vcpu->arch.dr6 &= ~15;
    		vcpu->arch.dr6 |= DR6_BS | DR6_RTM;
    		kvm_queue_exception(vcpu, DB_VECTOR);
    	}
    }
    
    int kvm_skip_emulated_instruction(struct kvm_vcpu *vcpu)
    {
    	unsigned long rflags = kvm_x86_ops->get_rflags(vcpu);
    	int r = EMULATE_DONE;
    
    	kvm_x86_ops->skip_emulated_instruction(vcpu);
    
    	/*
    	 * rflags is the old, "raw" value of the flags.  The new value has
    	 * not been saved yet.
    	 *
    	 * This is correct even for TF set by the guest, because "the
    	 * processor will not generate this exception after the instruction
    	 * that sets the TF flag".
    	 */
    	if (unlikely(rflags & X86_EFLAGS_TF))
    		kvm_vcpu_do_singlestep(vcpu, &r);
    	return r == EMULATE_DONE;
    }
    EXPORT_SYMBOL_GPL(kvm_skip_emulated_instruction);
    
    static bool kvm_vcpu_check_breakpoint(struct kvm_vcpu *vcpu, int *r)
    {
    	if (unlikely(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP) &&
    	    (vcpu->arch.guest_debug_dr7 & DR7_BP_EN_MASK)) {
    		struct kvm_run *kvm_run = vcpu->run;
    		unsigned long eip = kvm_get_linear_rip(vcpu);
    		u32 dr6 = kvm_vcpu_check_hw_bp(eip, 0,
    					   vcpu->arch.guest_debug_dr7,
    					   vcpu->arch.eff_db);
    
    		if (dr6 != 0) {
    			kvm_run->debug.arch.dr6 = dr6 | DR6_FIXED_1 | DR6_RTM;
    			kvm_run->debug.arch.pc = eip;
    			kvm_run->debug.arch.exception = DB_VECTOR;
    			kvm_run->exit_reason = KVM_EXIT_DEBUG;
    			*r = EMULATE_USER_EXIT;
    			return true;
    		}
    	}
    
    	if (unlikely(vcpu->arch.dr7 & DR7_BP_EN_MASK) &&
    	    !(kvm_get_rflags(vcpu) & X86_EFLAGS_RF)) {
    		unsigned long eip = kvm_get_linear_rip(vcpu);
    		u32 dr6 = kvm_vcpu_check_hw_bp(eip, 0,
    					   vcpu->arch.dr7,
    					   vcpu->arch.db);
    
    		if (dr6 != 0) {
    			vcpu->arch.dr6 &= ~15;
    			vcpu->arch.dr6 |= dr6 | DR6_RTM;
    			kvm_queue_exception(vcpu, DB_VECTOR);
    			*r = EMULATE_DONE;
    			return true;
    		}
    	}
    
    	return false;
    }
    
    static bool is_vmware_backdoor_opcode(struct x86_emulate_ctxt *ctxt)
    {
    	switch (ctxt->opcode_len) {
    	case 1:
    		switch (ctxt->b) {
    		case 0xe4:	/* IN */
    		case 0xe5:
    		case 0xec:
    		case 0xed:
    		case 0xe6:	/* OUT */
    		case 0xe7:
    		case 0xee:
    		case 0xef:
    		case 0x6c:	/* INS */
    		case 0x6d:
    		case 0x6e:	/* OUTS */
    		case 0x6f:
    			return true;
    		}
    		break;
    	case 2:
    		switch (ctxt->b) {
    		case 0x33:	/* RDPMC */
    			return true;
    		}
    		break;
    	}
    
    	return false;
    }
    
    int x86_emulate_instruction(struct kvm_vcpu *vcpu,
    			    unsigned long cr2,
    			    int emulation_type,
    			    void *insn,
    			    int insn_len)
    {
    	int r;
    	struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt;
    	bool writeback = true;
    	bool write_fault_to_spt = vcpu->arch.write_fault_to_shadow_pgtable;
    
    	vcpu->arch.l1tf_flush_l1d = true;
    
    	/*
    	 * Clear write_fault_to_shadow_pgtable here to ensure it is
    	 * never reused.
    	 */
    	vcpu->arch.write_fault_to_shadow_pgtable = false;
    	kvm_clear_exception_queue(vcpu);
    
    	if (!(emulation_type & EMULTYPE_NO_DECODE)) {
    		init_emulate_ctxt(vcpu);
    
    		/*
    		 * We will reenter on the same instruction since
    		 * we do not set complete_userspace_io.  This does not
    		 * handle watchpoints yet, those would be handled in
    		 * the emulate_ops.
    		 */
    		if (!(emulation_type & EMULTYPE_SKIP) &&
    		    kvm_vcpu_check_breakpoint(vcpu, &r))
    			return r;
    
    		ctxt->interruptibility = 0;
    		ctxt->have_exception = false;
    		ctxt->exception.vector = -1;
    		ctxt->perm_ok = false;
    
    		ctxt->ud = emulation_type & EMULTYPE_TRAP_UD;
    
    		r = x86_decode_insn(ctxt, insn, insn_len);
    
    		trace_kvm_emulate_insn_start(vcpu);
    		++vcpu->stat.insn_emulation;
    		if (r != EMULATION_OK)  {
    			if (emulation_type & EMULTYPE_TRAP_UD)
    				return EMULATE_FAIL;
    			if (reexecute_instruction(vcpu, cr2, write_fault_to_spt,
    						emulation_type))
    				return EMULATE_DONE;
    			if (ctxt->have_exception && inject_emulated_exception(vcpu))
    				return EMULATE_DONE;
    			if (emulation_type & EMULTYPE_SKIP)
    				return EMULATE_FAIL;
    			return handle_emulation_failure(vcpu, emulation_type);
    		}
    	}
    
    	if ((emulation_type & EMULTYPE_VMWARE) &&
    	    !is_vmware_backdoor_opcode(ctxt))
    		return EMULATE_FAIL;
    
    	if (emulation_type & EMULTYPE_SKIP) {
    		kvm_rip_write(vcpu, ctxt->_eip);
    		if (ctxt->eflags & X86_EFLAGS_RF)
    			kvm_set_rflags(vcpu, ctxt->eflags & ~X86_EFLAGS_RF);
    		return EMULATE_DONE;
    	}
    
    	if (retry_instruction(ctxt, cr2, emulation_type))
    		return EMULATE_DONE;
    
    	/* this is needed for vmware backdoor interface to work since it
    	   changes registers values  during IO operation */
    	if (vcpu->arch.emulate_regs_need_sync_from_vcpu) {
    		vcpu->arch.emulate_regs_need_sync_from_vcpu = false;
    		emulator_invalidate_register_cache(ctxt);
    	}
    
    restart:
    	/* Save the faulting GPA (cr2) in the address field */
    	ctxt->exception.address = cr2;
    
    	r = x86_emulate_insn(ctxt);
    
    	if (r == EMULATION_INTERCEPTED)
    		return EMULATE_DONE;
    
    	if (r == EMULATION_FAILED) {
    		if (reexecute_instruction(vcpu, cr2, write_fault_to_spt,
    					emulation_type))
    			return EMULATE_DONE;
    
    		return handle_emulation_failure(vcpu, emulation_type);
    	}
    
    	if (ctxt->have_exception) {
    		r = EMULATE_DONE;
    		if (inject_emulated_exception(vcpu))
    			return r;
    	} else if (vcpu->arch.pio.count) {
    		if (!vcpu->arch.pio.in) {
    			/* FIXME: return into emulator if single-stepping.  */
    			vcpu->arch.pio.count = 0;
    		} else {
    			writeback = false;
    			vcpu->arch.complete_userspace_io = complete_emulated_pio;
    		}
    		r = EMULATE_USER_EXIT;
    	} else if (vcpu->mmio_needed) {
    		if (!vcpu->mmio_is_write)
    			writeback = false;
    		r = EMULATE_USER_EXIT;
    		vcpu->arch.complete_userspace_io = complete_emulated_mmio;
    	} else if (r == EMULATION_RESTART)
    		goto restart;
    	else
    		r = EMULATE_DONE;
    
    	if (writeback) {
    		unsigned long rflags = kvm_x86_ops->get_rflags(vcpu);
    		toggle_interruptibility(vcpu, ctxt->interruptibility);
    		vcpu->arch.emulate_regs_need_sync_to_vcpu = false;
    		kvm_rip_write(vcpu, ctxt->eip);
    		if (r == EMULATE_DONE &&
    		    (ctxt->tf || (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)))
    			kvm_vcpu_do_singlestep(vcpu, &r);
    		if (!ctxt->have_exception ||
    		    exception_type(ctxt->exception.vector) == EXCPT_TRAP)
    			__kvm_set_rflags(vcpu, ctxt->eflags);
    
    		/*
    		 * For STI, interrupts are shadowed; so KVM_REQ_EVENT will
    		 * do nothing, and it will be requested again as soon as
    		 * the shadow expires.  But we still need to check here,
    		 * because POPF has no interrupt shadow.
    		 */
    		if (unlikely((ctxt->eflags & ~rflags) & X86_EFLAGS_IF))
    			kvm_make_request(KVM_REQ_EVENT, vcpu);
    	} else
    		vcpu->arch.emulate_regs_need_sync_to_vcpu = true;
    
    	return r;
    }
    
    int kvm_emulate_instruction(struct kvm_vcpu *vcpu, int emulation_type)
    {
    	return x86_emulate_instruction(vcpu, 0, emulation_type, NULL, 0);
    }
    EXPORT_SYMBOL_GPL(kvm_emulate_instruction);
    
    int kvm_emulate_instruction_from_buffer(struct kvm_vcpu *vcpu,
    					void *insn, int insn_len)
    {
    	return x86_emulate_instruction(vcpu, 0, 0, insn, insn_len);
    }
    EXPORT_SYMBOL_GPL(kvm_emulate_instruction_from_buffer);
    
    static int kvm_fast_pio_out(struct kvm_vcpu *vcpu, int size,
    			    unsigned short port)
    {
    	unsigned long val = kvm_register_read(vcpu, VCPU_REGS_RAX);
    	int ret = emulator_pio_out_emulated(&vcpu->arch.emulate_ctxt,
    					    size, port, &val, 1);
    	/* do not return to emulator after return from userspace */
    	vcpu->arch.pio.count = 0;
    	return ret;
    }
    
    static int complete_fast_pio_in(struct kvm_vcpu *vcpu)
    {
    	unsigned long val;
    
    	/* We should only ever be called with arch.pio.count equal to 1 */
    	BUG_ON(vcpu->arch.pio.count != 1);
    
    	/* For size less than 4 we merge, else we zero extend */
    	val = (vcpu->arch.pio.size < 4) ? kvm_register_read(vcpu, VCPU_REGS_RAX)
    					: 0;
    
    	/*
    	 * Since vcpu->arch.pio.count == 1 let emulator_pio_in_emulated perform
    	 * the copy and tracing
    	 */
    	emulator_pio_in_emulated(&vcpu->arch.emulate_ctxt, vcpu->arch.pio.size,
    				 vcpu->arch.pio.port, &val, 1);
    	kvm_register_write(vcpu, VCPU_REGS_RAX, val);
    
    	return 1;
    }
    
    static int kvm_fast_pio_in(struct kvm_vcpu *vcpu, int size,
    			   unsigned short port)
    {
    	unsigned long val;
    	int ret;
    
    	/* For size less than 4 we merge, else we zero extend */
    	val = (size < 4) ? kvm_register_read(vcpu, VCPU_REGS_RAX) : 0;
    
    	ret = emulator_pio_in_emulated(&vcpu->arch.emulate_ctxt, size, port,
    				       &val, 1);
    	if (ret) {
    		kvm_register_write(vcpu, VCPU_REGS_RAX, val);
    		return ret;
    	}
    
    	vcpu->arch.complete_userspace_io = complete_fast_pio_in;
    
    	return 0;
    }
    
    int kvm_fast_pio(struct kvm_vcpu *vcpu, int size, unsigned short port, int in)
    {
    	int ret = kvm_skip_emulated_instruction(vcpu);
    
    	/*
    	 * TODO: we might be squashing a KVM_GUESTDBG_SINGLESTEP-triggered
    	 * KVM_EXIT_DEBUG here.
    	 */
    	if (in)
    		return kvm_fast_pio_in(vcpu, size, port) && ret;
    	else
    		return kvm_fast_pio_out(vcpu, size, port) && ret;
    }
    EXPORT_SYMBOL_GPL(kvm_fast_pio);
    
    static int kvmclock_cpu_down_prep(unsigned int cpu)
    {
    	__this_cpu_write(cpu_tsc_khz, 0);
    	return 0;
    }
    
    static void tsc_khz_changed(void *data)
    {
    	struct cpufreq_freqs *freq = data;
    	unsigned long khz = 0;
    
    	if (data)
    		khz = freq->new;
    	else if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC))
    		khz = cpufreq_quick_get(raw_smp_processor_id());
    	if (!khz)
    		khz = tsc_khz;
    	__this_cpu_write(cpu_tsc_khz, khz);
    }
    
    #ifdef CONFIG_X86_64
    static void kvm_hyperv_tsc_notifier(void)
    {
    	struct kvm *kvm;
    	struct kvm_vcpu *vcpu;
    	int cpu;
    
    	spin_lock(&kvm_lock);
    	list_for_each_entry(kvm, &vm_list, vm_list)
    		kvm_make_mclock_inprogress_request(kvm);
    
    	hyperv_stop_tsc_emulation();
    
    	/* TSC frequency always matches when on Hyper-V */
    	for_each_present_cpu(cpu)
    		per_cpu(cpu_tsc_khz, cpu) = tsc_khz;
    	kvm_max_guest_tsc_khz = tsc_khz;
    
    	list_for_each_entry(kvm, &vm_list, vm_list) {
    		struct kvm_arch *ka = &kvm->arch;
    
    		spin_lock(&ka->pvclock_gtod_sync_lock);
    
    		pvclock_update_vm_gtod_copy(kvm);
    
    		kvm_for_each_vcpu(cpu, vcpu, kvm)
    			kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
    
    		kvm_for_each_vcpu(cpu, vcpu, kvm)
    			kvm_clear_request(KVM_REQ_MCLOCK_INPROGRESS, vcpu);
    
    		spin_unlock(&ka->pvclock_gtod_sync_lock);
    	}
    	spin_unlock(&kvm_lock);
    }
    #endif
    
    static int kvmclock_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
    				     void *data)
    {
    	struct cpufreq_freqs *freq = data;
    	struct kvm *kvm;
    	struct kvm_vcpu *vcpu;
    	int i, send_ipi = 0;
    
    	/*
    	 * We allow guests to temporarily run on slowing clocks,
    	 * provided we notify them after, or to run on accelerating
    	 * clocks, provided we notify them before.  Thus time never
    	 * goes backwards.
    	 *
    	 * However, we have a problem.  We can't atomically update
    	 * the frequency of a given CPU from this function; it is
    	 * merely a notifier, which can be called from any CPU.
    	 * Changing the TSC frequency at arbitrary points in time
    	 * requires a recomputation of local variables related to
    	 * the TSC for each VCPU.  We must flag these local variables
    	 * to be updated and be sure the update takes place with the
    	 * new frequency before any guests proceed.
    	 *
    	 * Unfortunately, the combination of hotplug CPU and frequency
    	 * change creates an intractable locking scenario; the order
    	 * of when these callouts happen is undefined with respect to
    	 * CPU hotplug, and they can race with each other.  As such,
    	 * merely setting per_cpu(cpu_tsc_khz) = X during a hotadd is
    	 * undefined; you can actually have a CPU frequency change take
    	 * place in between the computation of X and the setting of the
    	 * variable.  To protect against this problem, all updates of
    	 * the per_cpu tsc_khz variable are done in an interrupt
    	 * protected IPI, and all callers wishing to update the value
    	 * must wait for a synchronous IPI to complete (which is trivial
    	 * if the caller is on the CPU already).  This establishes the
    	 * necessary total order on variable updates.
    	 *
    	 * Note that because a guest time update may take place
    	 * anytime after the setting of the VCPU's request bit, the
    	 * correct TSC value must be set before the request.  However,
    	 * to ensure the update actually makes it to any guest which
    	 * starts running in hardware virtualization between the set
    	 * and the acquisition of the spinlock, we must also ping the
    	 * CPU after setting the request bit.
    	 *
    	 */
    
    	if (val == CPUFREQ_PRECHANGE && freq->old > freq->new)
    		return 0;
    	if (val == CPUFREQ_POSTCHANGE && freq->old < freq->new)
    		return 0;
    
    	smp_call_function_single(freq->cpu, tsc_khz_changed, freq, 1);
    
    	spin_lock(&kvm_lock);
    	list_for_each_entry(kvm, &vm_list, vm_list) {
    		kvm_for_each_vcpu(i, vcpu, kvm) {
    			if (vcpu->cpu != freq->cpu)
    				continue;
    			kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
    			if (vcpu->cpu != smp_processor_id())
    				send_ipi = 1;
    		}
    	}
    	spin_unlock(&kvm_lock);
    
    	if (freq->old < freq->new && send_ipi) {
    		/*
    		 * We upscale the frequency.  Must make the guest
    		 * doesn't see old kvmclock values while running with
    		 * the new frequency, otherwise we risk the guest sees
    		 * time go backwards.
    		 *
    		 * In case we update the frequency for another cpu
    		 * (which might be in guest context) send an interrupt
    		 * to kick the cpu out of guest context.  Next time
    		 * guest context is entered kvmclock will be updated,
    		 * so the guest will not see stale values.
    		 */
    		smp_call_function_single(freq->cpu, tsc_khz_changed, freq, 1);
    	}
    	return 0;
    }
    
    static struct notifier_block kvmclock_cpufreq_notifier_block = {
    	.notifier_call  = kvmclock_cpufreq_notifier
    };
    
    static int kvmclock_cpu_online(unsigned int cpu)
    {
    	tsc_khz_changed(NULL);
    	return 0;
    }
    
    static void kvm_timer_init(void)
    {
    	max_tsc_khz = tsc_khz;
    
    	if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) {
    #ifdef CONFIG_CPU_FREQ
    		struct cpufreq_policy policy;
    		int cpu;
    
    		memset(&policy, 0, sizeof(policy));
    		cpu = get_cpu();
    		cpufreq_get_policy(&policy, cpu);
    		if (policy.cpuinfo.max_freq)
    			max_tsc_khz = policy.cpuinfo.max_freq;
    		put_cpu();
    #endif
    		cpufreq_register_notifier(&kvmclock_cpufreq_notifier_block,
    					  CPUFREQ_TRANSITION_NOTIFIER);
    	}
    	pr_debug("kvm: max_tsc_khz = %ld\n", max_tsc_khz);
    
    	cpuhp_setup_state(CPUHP_AP_X86_KVM_CLK_ONLINE, "x86/kvm/clk:online",
    			  kvmclock_cpu_online, kvmclock_cpu_down_prep);
    }
    
    DEFINE_PER_CPU(struct kvm_vcpu *, current_vcpu);
    EXPORT_PER_CPU_SYMBOL_GPL(current_vcpu);
    
    int kvm_is_in_guest(void)
    {
    	return __this_cpu_read(current_vcpu) != NULL;
    }
    
    static int kvm_is_user_mode(void)
    {
    	int user_mode = 3;
    
    	if (__this_cpu_read(current_vcpu))
    		user_mode = kvm_x86_ops->get_cpl(__this_cpu_read(current_vcpu));
    
    	return user_mode != 0;
    }
    
    static unsigned long kvm_get_guest_ip(void)
    {
    	unsigned long ip = 0;
    
    	if (__this_cpu_read(current_vcpu))
    		ip = kvm_rip_read(__this_cpu_read(current_vcpu));
    
    	return ip;
    }
    
    static struct perf_guest_info_callbacks kvm_guest_cbs = {
    	.is_in_guest		= kvm_is_in_guest,
    	.is_user_mode		= kvm_is_user_mode,
    	.get_guest_ip		= kvm_get_guest_ip,
    };
    
    static void kvm_set_mmio_spte_mask(void)
    {
    	u64 mask;
    	int maxphyaddr = boot_cpu_data.x86_phys_bits;
    
    	/*
    	 * Set the reserved bits and the present bit of an paging-structure
    	 * entry to generate page fault with PFER.RSV = 1.
    	 */
    
    	/*
    	 * Mask the uppermost physical address bit, which would be reserved as
    	 * long as the supported physical address width is less than 52.
    	 */
    	mask = 1ull << 51;
    
    	/* Set the present bit. */
    	mask |= 1ull;
    
    	/*
    	 * If reserved bit is not supported, clear the present bit to disable
    	 * mmio page fault.
    	 */
    	if (IS_ENABLED(CONFIG_X86_64) && maxphyaddr == 52)
    		mask &= ~1ull;
    
    	kvm_mmu_set_mmio_spte_mask(mask, mask);
    }
    
    #ifdef CONFIG_X86_64
    static void pvclock_gtod_update_fn(struct work_struct *work)
    {
    	struct kvm *kvm;
    
    	struct kvm_vcpu *vcpu;
    	int i;
    
    	spin_lock(&kvm_lock);
    	list_for_each_entry(kvm, &vm_list, vm_list)
    		kvm_for_each_vcpu(i, vcpu, kvm)
    			kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
    	atomic_set(&kvm_guest_has_master_clock, 0);
    	spin_unlock(&kvm_lock);
    }
    
    static DECLARE_WORK(pvclock_gtod_work, pvclock_gtod_update_fn);
    
    /*
     * Notification about pvclock gtod data update.
     */
    static int pvclock_gtod_notify(struct notifier_block *nb, unsigned long unused,
    			       void *priv)
    {
    	struct pvclock_gtod_data *gtod = &pvclock_gtod_data;
    	struct timekeeper *tk = priv;
    
    	update_pvclock_gtod(tk);
    
    	/* disable master clock if host does not trust, or does not
    	 * use, TSC based clocksource.
    	 */
    	if (!gtod_is_based_on_tsc(gtod->clock.vclock_mode) &&
    	    atomic_read(&kvm_guest_has_master_clock) != 0)
    		queue_work(system_long_wq, &pvclock_gtod_work);
    
    	return 0;
    }
    
    static struct notifier_block pvclock_gtod_notifier = {
    	.notifier_call = pvclock_gtod_notify,
    };
    #endif
    
    int kvm_arch_init(void *opaque)
    {
    	int r;
    	struct kvm_x86_ops *ops = opaque;
    
    	if (kvm_x86_ops) {
    		printk(KERN_ERR "kvm: already loaded the other module\n");
    		r = -EEXIST;
    		goto out;
    	}
    
    	if (!ops->cpu_has_kvm_support()) {
    		printk(KERN_ERR "kvm: no hardware support\n");
    		r = -EOPNOTSUPP;
    		goto out;
    	}
    	if (ops->disabled_by_bios()) {
    		printk(KERN_ERR "kvm: disabled by bios\n");
    		r = -EOPNOTSUPP;
    		goto out;
    	}
    
    	r = -ENOMEM;
    	shared_msrs = alloc_percpu(struct kvm_shared_msrs);
    	if (!shared_msrs) {
    		printk(KERN_ERR "kvm: failed to allocate percpu kvm_shared_msrs\n");
    		goto out;
    	}
    
    	r = kvm_mmu_module_init();
    	if (r)
    		goto out_free_percpu;
    
    	kvm_set_mmio_spte_mask();
    
    	kvm_x86_ops = ops;
    
    	kvm_mmu_set_mask_ptes(PT_USER_MASK, PT_ACCESSED_MASK,
    			PT_DIRTY_MASK, PT64_NX_MASK, 0,
    			PT_PRESENT_MASK, 0, sme_me_mask);
    	kvm_timer_init();
    
    	perf_register_guest_info_callbacks(&kvm_guest_cbs);
    
    	if (boot_cpu_has(X86_FEATURE_XSAVE))
    		host_xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
    
    	kvm_lapic_init();
    #ifdef CONFIG_X86_64
    	pvclock_gtod_register_notifier(&pvclock_gtod_notifier);
    
    	if (hypervisor_is_type(X86_HYPER_MS_HYPERV))
    		set_hv_tscchange_cb(kvm_hyperv_tsc_notifier);
    #endif
    
    	return 0;
    
    out_free_percpu:
    	free_percpu(shared_msrs);
    out:
    	return r;
    }
    
    void kvm_arch_exit(void)
    {
    #ifdef CONFIG_X86_64
    	if (hypervisor_is_type(X86_HYPER_MS_HYPERV))
    		clear_hv_tscchange_cb();
    #endif
    	kvm_lapic_exit();
    	perf_unregister_guest_info_callbacks(&kvm_guest_cbs);
    
    	if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC))
    		cpufreq_unregister_notifier(&kvmclock_cpufreq_notifier_block,
    					    CPUFREQ_TRANSITION_NOTIFIER);
    	cpuhp_remove_state_nocalls(CPUHP_AP_X86_KVM_CLK_ONLINE);
    #ifdef CONFIG_X86_64
    	pvclock_gtod_unregister_notifier(&pvclock_gtod_notifier);
    #endif
    	kvm_x86_ops = NULL;
    	kvm_mmu_module_exit();
    	free_percpu(shared_msrs);
    }
    
    int kvm_vcpu_halt(struct kvm_vcpu *vcpu)
    {
    	++vcpu->stat.halt_exits;
    	if (lapic_in_kernel(vcpu)) {
    		vcpu->arch.mp_state = KVM_MP_STATE_HALTED;
    		return 1;
    	} else {
    		vcpu->run->exit_reason = KVM_EXIT_HLT;
    		return 0;
    	}
    }
    EXPORT_SYMBOL_GPL(kvm_vcpu_halt);
    
    int kvm_emulate_halt(struct kvm_vcpu *vcpu)
    {
    	int ret = kvm_skip_emulated_instruction(vcpu);
    	/*
    	 * TODO: we might be squashing a GUESTDBG_SINGLESTEP-triggered
    	 * KVM_EXIT_DEBUG here.
    	 */
    	return kvm_vcpu_halt(vcpu) && ret;
    }
    EXPORT_SYMBOL_GPL(kvm_emulate_halt);
    
    #ifdef CONFIG_X86_64
    static int kvm_pv_clock_pairing(struct kvm_vcpu *vcpu, gpa_t paddr,
    			        unsigned long clock_type)
    {
    	struct kvm_clock_pairing clock_pairing;
    	struct timespec64 ts;
    	u64 cycle;
    	int ret;
    
    	if (clock_type != KVM_CLOCK_PAIRING_WALLCLOCK)
    		return -KVM_EOPNOTSUPP;
    
    	if (kvm_get_walltime_and_clockread(&ts, &cycle) == false)
    		return -KVM_EOPNOTSUPP;
    
    	clock_pairing.sec = ts.tv_sec;
    	clock_pairing.nsec = ts.tv_nsec;
    	clock_pairing.tsc = kvm_read_l1_tsc(vcpu, cycle);
    	clock_pairing.flags = 0;
    
    	ret = 0;
    	if (kvm_write_guest(vcpu->kvm, paddr, &clock_pairing,
    			    sizeof(struct kvm_clock_pairing)))
    		ret = -KVM_EFAULT;
    
    	return ret;
    }
    #endif
    
    /*
     * kvm_pv_kick_cpu_op:  Kick a vcpu.
     *
     * @apicid - apicid of vcpu to be kicked.
     */
    static void kvm_pv_kick_cpu_op(struct kvm *kvm, unsigned long flags, int apicid)
    {
    	struct kvm_lapic_irq lapic_irq;
    
    	lapic_irq.shorthand = 0;
    	lapic_irq.dest_mode = 0;
    	lapic_irq.level = 0;
    	lapic_irq.dest_id = apicid;
    	lapic_irq.msi_redir_hint = false;
    
    	lapic_irq.delivery_mode = APIC_DM_REMRD;
    	kvm_irq_delivery_to_apic(kvm, NULL, &lapic_irq, NULL);
    }
    
    void kvm_vcpu_deactivate_apicv(struct kvm_vcpu *vcpu)
    {
    	vcpu->arch.apicv_active = false;
    	kvm_x86_ops->refresh_apicv_exec_ctrl(vcpu);
    }
    
    int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
    {
    	unsigned long nr, a0, a1, a2, a3, ret;
    	int op_64_bit;
    
    	if (kvm_hv_hypercall_enabled(vcpu->kvm))
    		return kvm_hv_hypercall(vcpu);
    
    	nr = kvm_register_read(vcpu, VCPU_REGS_RAX);
    	a0 = kvm_register_read(vcpu, VCPU_REGS_RBX);
    	a1 = kvm_register_read(vcpu, VCPU_REGS_RCX);
    	a2 = kvm_register_read(vcpu, VCPU_REGS_RDX);
    	a3 = kvm_register_read(vcpu, VCPU_REGS_RSI);
    
    	trace_kvm_hypercall(nr, a0, a1, a2, a3);
    
    	op_64_bit = is_64_bit_mode(vcpu);
    	if (!op_64_bit) {
    		nr &= 0xFFFFFFFF;
    		a0 &= 0xFFFFFFFF;
    		a1 &= 0xFFFFFFFF;
    		a2 &= 0xFFFFFFFF;
    		a3 &= 0xFFFFFFFF;
    	}
    
    	if (kvm_x86_ops->get_cpl(vcpu) != 0) {
    		ret = -KVM_EPERM;
    		goto out;
    	}
    
    	switch (nr) {
    	case KVM_HC_VAPIC_POLL_IRQ:
    		ret = 0;
    		break;
    	case KVM_HC_KICK_CPU:
    		kvm_pv_kick_cpu_op(vcpu->kvm, a0, a1);
    		ret = 0;
    		break;
    #ifdef CONFIG_X86_64
    	case KVM_HC_CLOCK_PAIRING:
    		ret = kvm_pv_clock_pairing(vcpu, a0, a1);
    		break;
    	case KVM_HC_SEND_IPI:
    		ret = kvm_pv_send_ipi(vcpu->kvm, a0, a1, a2, a3, op_64_bit);
    		break;
    #endif
    	default:
    		ret = -KVM_ENOSYS;
    		break;
    	}
    out:
    	if (!op_64_bit)
    		ret = (u32)ret;
    	kvm_register_write(vcpu, VCPU_REGS_RAX, ret);
    
    	++vcpu->stat.hypercalls;
    	return kvm_skip_emulated_instruction(vcpu);
    }
    EXPORT_SYMBOL_GPL(kvm_emulate_hypercall);
    
    static int emulator_fix_hypercall(struct x86_emulate_ctxt *ctxt)
    {
    	struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
    	char instruction[3];
    	unsigned long rip = kvm_rip_read(vcpu);
    
    	kvm_x86_ops->patch_hypercall(vcpu, instruction);
    
    	return emulator_write_emulated(ctxt, rip, instruction, 3,
    		&ctxt->exception);
    }
    
    static int dm_request_for_irq_injection(struct kvm_vcpu *vcpu)
    {
    	return vcpu->run->request_interrupt_window &&
    		likely(!pic_in_kernel(vcpu->kvm));
    }
    
    static void post_kvm_run_save(struct kvm_vcpu *vcpu)
    {
    	struct kvm_run *kvm_run = vcpu->run;
    
    	kvm_run->if_flag = (kvm_get_rflags(vcpu) & X86_EFLAGS_IF) != 0;
    	kvm_run->flags = is_smm(vcpu) ? KVM_RUN_X86_SMM : 0;
    	kvm_run->cr8 = kvm_get_cr8(vcpu);
    	kvm_run->apic_base = kvm_get_apic_base(vcpu);
    	kvm_run->ready_for_interrupt_injection =
    		pic_in_kernel(vcpu->kvm) ||
    		kvm_vcpu_ready_for_interrupt_injection(vcpu);
    }
    
    static void update_cr8_intercept(struct kvm_vcpu *vcpu)
    {
    	int max_irr, tpr;
    
    	if (!kvm_x86_ops->update_cr8_intercept)
    		return;
    
    	if (!lapic_in_kernel(vcpu))
    		return;
    
    	if (vcpu->arch.apicv_active)
    		return;
    
    	if (!vcpu->arch.apic->vapic_addr)
    		max_irr = kvm_lapic_find_highest_irr(vcpu);
    	else
    		max_irr = -1;
    
    	if (max_irr != -1)
    		max_irr >>= 4;
    
    	tpr = kvm_lapic_get_cr8(vcpu);
    
    	kvm_x86_ops->update_cr8_intercept(vcpu, tpr, max_irr);
    }
    
    static int inject_pending_event(struct kvm_vcpu *vcpu, bool req_int_win)
    {
    	int r;
    
    	/* try to reinject previous events if any */
    
    	if (vcpu->arch.exception.injected)
    		kvm_x86_ops->queue_exception(vcpu);
    	/*
    	 * Do not inject an NMI or interrupt if there is a pending
    	 * exception.  Exceptions and interrupts are recognized at
    	 * instruction boundaries, i.e. the start of an instruction.
    	 * Trap-like exceptions, e.g. #DB, have higher priority than
    	 * NMIs and interrupts, i.e. traps are recognized before an
    	 * NMI/interrupt that's pending on the same instruction.
    	 * Fault-like exceptions, e.g. #GP and #PF, are the lowest
    	 * priority, but are only generated (pended) during instruction
    	 * execution, i.e. a pending fault-like exception means the
    	 * fault occurred on the *previous* instruction and must be
    	 * serviced prior to recognizing any new events in order to
    	 * fully complete the previous instruction.
    	 */
    	else if (!vcpu->arch.exception.pending) {
    		if (vcpu->arch.nmi_injected)
    			kvm_x86_ops->set_nmi(vcpu);
    		else if (vcpu->arch.interrupt.injected)
    			kvm_x86_ops->set_irq(vcpu);
    	}
    
    	/*
    	 * Call check_nested_events() even if we reinjected a previous event
    	 * in order for caller to determine if it should require immediate-exit
    	 * from L2 to L1 due to pending L1 events which require exit
    	 * from L2 to L1.
    	 */
    	if (is_guest_mode(vcpu) && kvm_x86_ops->check_nested_events) {
    		r = kvm_x86_ops->check_nested_events(vcpu, req_int_win);
    		if (r != 0)
    			return r;
    	}
    
    	/* try to inject new event if pending */
    	if (vcpu->arch.exception.pending) {
    		trace_kvm_inj_exception(vcpu->arch.exception.nr,
    					vcpu->arch.exception.has_error_code,
    					vcpu->arch.exception.error_code);
    
    		WARN_ON_ONCE(vcpu->arch.exception.injected);
    		vcpu->arch.exception.pending = false;
    		vcpu->arch.exception.injected = true;
    
    		if (exception_type(vcpu->arch.exception.nr) == EXCPT_FAULT)
    			__kvm_set_rflags(vcpu, kvm_get_rflags(vcpu) |
    					     X86_EFLAGS_RF);
    
    		if (vcpu->arch.exception.nr == DB_VECTOR &&
    		    (vcpu->arch.dr7 & DR7_GD)) {
    			vcpu->arch.dr7 &= ~DR7_GD;
    			kvm_update_dr7(vcpu);
    		}
    
    		kvm_x86_ops->queue_exception(vcpu);
    	}
    
    	/* Don't consider new event if we re-injected an event */
    	if (kvm_event_needs_reinjection(vcpu))
    		return 0;
    
    	if (vcpu->arch.smi_pending && !is_smm(vcpu) &&
    	    kvm_x86_ops->smi_allowed(vcpu)) {
    		vcpu->arch.smi_pending = false;
    		++vcpu->arch.smi_count;
    		enter_smm(vcpu);
    	} else if (vcpu->arch.nmi_pending && kvm_x86_ops->nmi_allowed(vcpu)) {
    		--vcpu->arch.nmi_pending;
    		vcpu->arch.nmi_injected = true;
    		kvm_x86_ops->set_nmi(vcpu);
    	} else if (kvm_cpu_has_injectable_intr(vcpu)) {
    		/*
    		 * Because interrupts can be injected asynchronously, we are
    		 * calling check_nested_events again here to avoid a race condition.
    		 * See https://lkml.org/lkml/2014/7/2/60 for discussion about this
    		 * proposal and current concerns.  Perhaps we should be setting
    		 * KVM_REQ_EVENT only on certain events and not unconditionally?
    		 */
    		if (is_guest_mode(vcpu) && kvm_x86_ops->check_nested_events) {
    			r = kvm_x86_ops->check_nested_events(vcpu, req_int_win);
    			if (r != 0)
    				return r;
    		}
    		if (kvm_x86_ops->interrupt_allowed(vcpu)) {
    			kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu),
    					    false);
    			kvm_x86_ops->set_irq(vcpu);
    		}
    	}
    
    	return 0;
    }
    
    static void process_nmi(struct kvm_vcpu *vcpu)
    {
    	unsigned limit = 2;
    
    	/*
    	 * x86 is limited to one NMI running, and one NMI pending after it.
    	 * If an NMI is already in progress, limit further NMIs to just one.
    	 * Otherwise, allow two (and we'll inject the first one immediately).
    	 */
    	if (kvm_x86_ops->get_nmi_mask(vcpu) || vcpu->arch.nmi_injected)
    		limit = 1;
    
    	vcpu->arch.nmi_pending += atomic_xchg(&vcpu->arch.nmi_queued, 0);
    	vcpu->arch.nmi_pending = min(vcpu->arch.nmi_pending, limit);
    	kvm_make_request(KVM_REQ_EVENT, vcpu);
    }
    
    static u32 enter_smm_get_segment_flags(struct kvm_segment *seg)
    {
    	u32 flags = 0;
    	flags |= seg->g       << 23;
    	flags |= seg->db      << 22;
    	flags |= seg->l       << 21;
    	flags |= seg->avl     << 20;
    	flags |= seg->present << 15;
    	flags |= seg->dpl     << 13;
    	flags |= seg->s       << 12;
    	flags |= seg->type    << 8;
    	return flags;
    }
    
    static void enter_smm_save_seg_32(struct kvm_vcpu *vcpu, char *buf, int n)
    {
    	struct kvm_segment seg;
    	int offset;
    
    	kvm_get_segment(vcpu, &seg, n);
    	put_smstate(u32, buf, 0x7fa8 + n * 4, seg.selector);
    
    	if (n < 3)
    		offset = 0x7f84 + n * 12;
    	else
    		offset = 0x7f2c + (n - 3) * 12;
    
    	put_smstate(u32, buf, offset + 8, seg.base);
    	put_smstate(u32, buf, offset + 4, seg.limit);
    	put_smstate(u32, buf, offset, enter_smm_get_segment_flags(&seg));
    }
    
    #ifdef CONFIG_X86_64
    static void enter_smm_save_seg_64(struct kvm_vcpu *vcpu, char *buf, int n)
    {
    	struct kvm_segment seg;
    	int offset;
    	u16 flags;
    
    	kvm_get_segment(vcpu, &seg, n);
    	offset = 0x7e00 + n * 16;
    
    	flags = enter_smm_get_segment_flags(&seg) >> 8;
    	put_smstate(u16, buf, offset, seg.selector);
    	put_smstate(u16, buf, offset + 2, flags);
    	put_smstate(u32, buf, offset + 4, seg.limit);
    	put_smstate(u64, buf, offset + 8, seg.base);
    }
    #endif
    
    static void enter_smm_save_state_32(struct kvm_vcpu *vcpu, char *buf)
    {
    	struct desc_ptr dt;
    	struct kvm_segment seg;
    	unsigned long val;
    	int i;
    
    	put_smstate(u32, buf, 0x7ffc, kvm_read_cr0(vcpu));
    	put_smstate(u32, buf, 0x7ff8, kvm_read_cr3(vcpu));
    	put_smstate(u32, buf, 0x7ff4, kvm_get_rflags(vcpu));
    	put_smstate(u32, buf, 0x7ff0, kvm_rip_read(vcpu));
    
    	for (i = 0; i < 8; i++)
    		put_smstate(u32, buf, 0x7fd0 + i * 4, kvm_register_read(vcpu, i));
    
    	kvm_get_dr(vcpu, 6, &val);
    	put_smstate(u32, buf, 0x7fcc, (u32)val);
    	kvm_get_dr(vcpu, 7, &val);
    	put_smstate(u32, buf, 0x7fc8, (u32)val);
    
    	kvm_get_segment(vcpu, &seg, VCPU_SREG_TR);
    	put_smstate(u32, buf, 0x7fc4, seg.selector);
    	put_smstate(u32, buf, 0x7f64, seg.base);
    	put_smstate(u32, buf, 0x7f60, seg.limit);
    	put_smstate(u32, buf, 0x7f5c, enter_smm_get_segment_flags(&seg));
    
    	kvm_get_segment(vcpu, &seg, VCPU_SREG_LDTR);
    	put_smstate(u32, buf, 0x7fc0, seg.selector);
    	put_smstate(u32, buf, 0x7f80, seg.base);
    	put_smstate(u32, buf, 0x7f7c, seg.limit);
    	put_smstate(u32, buf, 0x7f78, enter_smm_get_segment_flags(&seg));
    
    	kvm_x86_ops->get_gdt(vcpu, &dt);
    	put_smstate(u32, buf, 0x7f74, dt.address);
    	put_smstate(u32, buf, 0x7f70, dt.size);
    
    	kvm_x86_ops->get_idt(vcpu, &dt);
    	put_smstate(u32, buf, 0x7f58, dt.address);
    	put_smstate(u32, buf, 0x7f54, dt.size);
    
    	for (i = 0; i < 6; i++)
    		enter_smm_save_seg_32(vcpu, buf, i);
    
    	put_smstate(u32, buf, 0x7f14, kvm_read_cr4(vcpu));
    
    	/* revision id */
    	put_smstate(u32, buf, 0x7efc, 0x00020000);
    	put_smstate(u32, buf, 0x7ef8, vcpu->arch.smbase);
    }
    
    static void enter_smm_save_state_64(struct kvm_vcpu *vcpu, char *buf)
    {
    #ifdef CONFIG_X86_64
    	struct desc_ptr dt;
    	struct kvm_segment seg;
    	unsigned long val;
    	int i;
    
    	for (i = 0; i < 16; i++)
    		put_smstate(u64, buf, 0x7ff8 - i * 8, kvm_register_read(vcpu, i));
    
    	put_smstate(u64, buf, 0x7f78, kvm_rip_read(vcpu));
    	put_smstate(u32, buf, 0x7f70, kvm_get_rflags(vcpu));
    
    	kvm_get_dr(vcpu, 6, &val);
    	put_smstate(u64, buf, 0x7f68, val);
    	kvm_get_dr(vcpu, 7, &val);
    	put_smstate(u64, buf, 0x7f60, val);
    
    	put_smstate(u64, buf, 0x7f58, kvm_read_cr0(vcpu));
    	put_smstate(u64, buf, 0x7f50, kvm_read_cr3(vcpu));
    	put_smstate(u64, buf, 0x7f48, kvm_read_cr4(vcpu));
    
    	put_smstate(u32, buf, 0x7f00, vcpu->arch.smbase);
    
    	/* revision id */
    	put_smstate(u32, buf, 0x7efc, 0x00020064);
    
    	put_smstate(u64, buf, 0x7ed0, vcpu->arch.efer);
    
    	kvm_get_segment(vcpu, &seg, VCPU_SREG_TR);
    	put_smstate(u16, buf, 0x7e90, seg.selector);
    	put_smstate(u16, buf, 0x7e92, enter_smm_get_segment_flags(&seg) >> 8);
    	put_smstate(u32, buf, 0x7e94, seg.limit);
    	put_smstate(u64, buf, 0x7e98, seg.base);
    
    	kvm_x86_ops->get_idt(vcpu, &dt);
    	put_smstate(u32, buf, 0x7e84, dt.size);
    	put_smstate(u64, buf, 0x7e88, dt.address);
    
    	kvm_get_segment(vcpu, &seg, VCPU_SREG_LDTR);
    	put_smstate(u16, buf, 0x7e70, seg.selector);
    	put_smstate(u16, buf, 0x7e72, enter_smm_get_segment_flags(&seg) >> 8);
    	put_smstate(u32, buf, 0x7e74, seg.limit);
    	put_smstate(u64, buf, 0x7e78, seg.base);
    
    	kvm_x86_ops->get_gdt(vcpu, &dt);
    	put_smstate(u32, buf, 0x7e64, dt.size);
    	put_smstate(u64, buf, 0x7e68, dt.address);
    
    	for (i = 0; i < 6; i++)
    		enter_smm_save_seg_64(vcpu, buf, i);
    #else
    	WARN_ON_ONCE(1);
    #endif
    }
    
    static void enter_smm(struct kvm_vcpu *vcpu)
    {
    	struct kvm_segment cs, ds;
    	struct desc_ptr dt;
    	char buf[512];
    	u32 cr0;
    
    	trace_kvm_enter_smm(vcpu->vcpu_id, vcpu->arch.smbase, true);
    	memset(buf, 0, 512);
    	if (guest_cpuid_has(vcpu, X86_FEATURE_LM))
    		enter_smm_save_state_64(vcpu, buf);
    	else
    		enter_smm_save_state_32(vcpu, buf);
    
    	/*
    	 * Give pre_enter_smm() a chance to make ISA-specific changes to the
    	 * vCPU state (e.g. leave guest mode) after we've saved the state into
    	 * the SMM state-save area.
    	 */
    	kvm_x86_ops->pre_enter_smm(vcpu, buf);
    
    	vcpu->arch.hflags |= HF_SMM_MASK;
    	kvm_vcpu_write_guest(vcpu, vcpu->arch.smbase + 0xfe00, buf, sizeof(buf));
    
    	if (kvm_x86_ops->get_nmi_mask(vcpu))
    		vcpu->arch.hflags |= HF_SMM_INSIDE_NMI_MASK;
    	else
    		kvm_x86_ops->set_nmi_mask(vcpu, true);
    
    	kvm_set_rflags(vcpu, X86_EFLAGS_FIXED);
    	kvm_rip_write(vcpu, 0x8000);
    
    	cr0 = vcpu->arch.cr0 & ~(X86_CR0_PE | X86_CR0_EM | X86_CR0_TS | X86_CR0_PG);
    	kvm_x86_ops->set_cr0(vcpu, cr0);
    	vcpu->arch.cr0 = cr0;
    
    	kvm_x86_ops->set_cr4(vcpu, 0);
    
    	/* Undocumented: IDT limit is set to zero on entry to SMM.  */
    	dt.address = dt.size = 0;
    	kvm_x86_ops->set_idt(vcpu, &dt);
    
    	__kvm_set_dr(vcpu, 7, DR7_FIXED_1);
    
    	cs.selector = (vcpu->arch.smbase >> 4) & 0xffff;
    	cs.base = vcpu->arch.smbase;
    
    	ds.selector = 0;
    	ds.base = 0;
    
    	cs.limit    = ds.limit = 0xffffffff;
    	cs.type     = ds.type = 0x3;
    	cs.dpl      = ds.dpl = 0;
    	cs.db       = ds.db = 0;
    	cs.s        = ds.s = 1;
    	cs.l        = ds.l = 0;
    	cs.g        = ds.g = 1;
    	cs.avl      = ds.avl = 0;
    	cs.present  = ds.present = 1;
    	cs.unusable = ds.unusable = 0;
    	cs.padding  = ds.padding = 0;
    
    	kvm_set_segment(vcpu, &cs, VCPU_SREG_CS);
    	kvm_set_segment(vcpu, &ds, VCPU_SREG_DS);
    	kvm_set_segment(vcpu, &ds, VCPU_SREG_ES);
    	kvm_set_segment(vcpu, &ds, VCPU_SREG_FS);
    	kvm_set_segment(vcpu, &ds, VCPU_SREG_GS);
    	kvm_set_segment(vcpu, &ds, VCPU_SREG_SS);
    
    	if (guest_cpuid_has(vcpu, X86_FEATURE_LM))
    		kvm_x86_ops->set_efer(vcpu, 0);
    
    	kvm_update_cpuid(vcpu);
    	kvm_mmu_reset_context(vcpu);
    }
    
    static void process_smi(struct kvm_vcpu *vcpu)
    {
    	vcpu->arch.smi_pending = true;
    	kvm_make_request(KVM_REQ_EVENT, vcpu);
    }
    
    void kvm_make_scan_ioapic_request(struct kvm *kvm)
    {
    	kvm_make_all_cpus_request(kvm, KVM_REQ_SCAN_IOAPIC);
    }
    
    static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu)
    {
    	if (!kvm_apic_hw_enabled(vcpu->arch.apic))
    		return;
    
    	bitmap_zero(vcpu->arch.ioapic_handled_vectors, 256);
    
    	if (irqchip_split(vcpu->kvm))
    		kvm_scan_ioapic_routes(vcpu, vcpu->arch.ioapic_handled_vectors);
    	else {
    		if (vcpu->arch.apicv_active)
    			kvm_x86_ops->sync_pir_to_irr(vcpu);
    		kvm_ioapic_scan_entry(vcpu, vcpu->arch.ioapic_handled_vectors);
    	}
    
    	if (is_guest_mode(vcpu))
    		vcpu->arch.load_eoi_exitmap_pending = true;
    	else
    		kvm_make_request(KVM_REQ_LOAD_EOI_EXITMAP, vcpu);
    }
    
    static void vcpu_load_eoi_exitmap(struct kvm_vcpu *vcpu)
    {
    	u64 eoi_exit_bitmap[4];
    
    	if (!kvm_apic_hw_enabled(vcpu->arch.apic))
    		return;
    
    	bitmap_or((ulong *)eoi_exit_bitmap, vcpu->arch.ioapic_handled_vectors,
    		  vcpu_to_synic(vcpu)->vec_bitmap, 256);
    	kvm_x86_ops->load_eoi_exitmap(vcpu, eoi_exit_bitmap);
    }
    
    int kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
    		unsigned long start, unsigned long end,
    		bool blockable)
    {
    	unsigned long apic_address;
    
    	/*
    	 * The physical address of apic access page is stored in the VMCS.
    	 * Update it when it becomes invalid.
    	 */
    	apic_address = gfn_to_hva(kvm, APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT);
    	if (start <= apic_address && apic_address < end)
    		kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD);
    
    	return 0;
    }
    
    void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
    {
    	struct page *page = NULL;
    
    	if (!lapic_in_kernel(vcpu))
    		return;
    
    	if (!kvm_x86_ops->set_apic_access_page_addr)
    		return;
    
    	page = gfn_to_page(vcpu->kvm, APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT);
    	if (is_error_page(page))
    		return;
    	kvm_x86_ops->set_apic_access_page_addr(vcpu, page_to_phys(page));
    
    	/*
    	 * Do not pin apic access page in memory, the MMU notifier
    	 * will call us again if it is migrated or swapped out.
    	 */
    	put_page(page);
    }
    EXPORT_SYMBOL_GPL(kvm_vcpu_reload_apic_access_page);
    
    void __kvm_request_immediate_exit(struct kvm_vcpu *vcpu)
    {
    	smp_send_reschedule(vcpu->cpu);
    }
    EXPORT_SYMBOL_GPL(__kvm_request_immediate_exit);
    
    /*
     * Returns 1 to let vcpu_run() continue the guest execution loop without
     * exiting to the userspace.  Otherwise, the value will be returned to the
     * userspace.
     */
    static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
    {
    	int r;
    	bool req_int_win =
    		dm_request_for_irq_injection(vcpu) &&
    		kvm_cpu_accept_dm_intr(vcpu);
    
    	bool req_immediate_exit = false;
    
    	if (kvm_request_pending(vcpu)) {
    		if (kvm_check_request(KVM_REQ_GET_VMCS12_PAGES, vcpu))
    			kvm_x86_ops->get_vmcs12_pages(vcpu);
    		if (kvm_check_request(KVM_REQ_MMU_RELOAD, vcpu))
    			kvm_mmu_unload(vcpu);
    		if (kvm_check_request(KVM_REQ_MIGRATE_TIMER, vcpu))
    			__kvm_migrate_timers(vcpu);
    		if (kvm_check_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu))
    			kvm_gen_update_masterclock(vcpu->kvm);
    		if (kvm_check_request(KVM_REQ_GLOBAL_CLOCK_UPDATE, vcpu))
    			kvm_gen_kvmclock_update(vcpu);
    		if (kvm_check_request(KVM_REQ_CLOCK_UPDATE, vcpu)) {
    			r = kvm_guest_time_update(vcpu);
    			if (unlikely(r))
    				goto out;
    		}
    		if (kvm_check_request(KVM_REQ_MMU_SYNC, vcpu))
    			kvm_mmu_sync_roots(vcpu);
    		if (kvm_check_request(KVM_REQ_LOAD_CR3, vcpu))
    			kvm_mmu_load_cr3(vcpu);
    		if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu))
    			kvm_vcpu_flush_tlb(vcpu, true);
    		if (kvm_check_request(KVM_REQ_REPORT_TPR_ACCESS, vcpu)) {
    			vcpu->run->exit_reason = KVM_EXIT_TPR_ACCESS;
    			r = 0;
    			goto out;
    		}
    		if (kvm_check_request(KVM_REQ_TRIPLE_FAULT, vcpu)) {
    			vcpu->run->exit_reason = KVM_EXIT_SHUTDOWN;
    			vcpu->mmio_needed = 0;
    			r = 0;
    			goto out;
    		}
    		if (kvm_check_request(KVM_REQ_APF_HALT, vcpu)) {
    			/* Page is swapped out. Do synthetic halt */
    			vcpu->arch.apf.halted = true;
    			r = 1;
    			goto out;
    		}
    		if (kvm_check_request(KVM_REQ_STEAL_UPDATE, vcpu))
    			record_steal_time(vcpu);
    		if (kvm_check_request(KVM_REQ_SMI, vcpu))
    			process_smi(vcpu);
    		if (kvm_check_request(KVM_REQ_NMI, vcpu))
    			process_nmi(vcpu);
    		if (kvm_check_request(KVM_REQ_PMU, vcpu))
    			kvm_pmu_handle_event(vcpu);
    		if (kvm_check_request(KVM_REQ_PMI, vcpu))
    			kvm_pmu_deliver_pmi(vcpu);
    		if (kvm_check_request(KVM_REQ_IOAPIC_EOI_EXIT, vcpu)) {
    			BUG_ON(vcpu->arch.pending_ioapic_eoi > 255);
    			if (test_bit(vcpu->arch.pending_ioapic_eoi,
    				     vcpu->arch.ioapic_handled_vectors)) {
    				vcpu->run->exit_reason = KVM_EXIT_IOAPIC_EOI;
    				vcpu->run->eoi.vector =
    						vcpu->arch.pending_ioapic_eoi;
    				r = 0;
    				goto out;
    			}
    		}
    		if (kvm_check_request(KVM_REQ_SCAN_IOAPIC, vcpu))
    			vcpu_scan_ioapic(vcpu);
    		if (kvm_check_request(KVM_REQ_LOAD_EOI_EXITMAP, vcpu))
    			vcpu_load_eoi_exitmap(vcpu);
    		if (kvm_check_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu))
    			kvm_vcpu_reload_apic_access_page(vcpu);
    		if (kvm_check_request(KVM_REQ_HV_CRASH, vcpu)) {
    			vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
    			vcpu->run->system_event.type = KVM_SYSTEM_EVENT_CRASH;
    			r = 0;
    			goto out;
    		}
    		if (kvm_check_request(KVM_REQ_HV_RESET, vcpu)) {
    			vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
    			vcpu->run->system_event.type = KVM_SYSTEM_EVENT_RESET;
    			r = 0;
    			goto out;
    		}
    		if (kvm_check_request(KVM_REQ_HV_EXIT, vcpu)) {
    			vcpu->run->exit_reason = KVM_EXIT_HYPERV;
    			vcpu->run->hyperv = vcpu->arch.hyperv.exit;
    			r = 0;
    			goto out;
    		}
    
    		/*
    		 * KVM_REQ_HV_STIMER has to be processed after
    		 * KVM_REQ_CLOCK_UPDATE, because Hyper-V SynIC timers
    		 * depend on the guest clock being up-to-date
    		 */
    		if (kvm_check_request(KVM_REQ_HV_STIMER, vcpu))
    			kvm_hv_process_stimers(vcpu);
    	}
    
    	if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win) {
    		++vcpu->stat.req_event;
    		kvm_apic_accept_events(vcpu);
    		if (vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED) {
    			r = 1;
    			goto out;
    		}
    
    		if (inject_pending_event(vcpu, req_int_win) != 0)
    			req_immediate_exit = true;
    		else {
    			/* Enable SMI/NMI/IRQ window open exits if needed.
    			 *
    			 * SMIs have three cases:
    			 * 1) They can be nested, and then there is nothing to
    			 *    do here because RSM will cause a vmexit anyway.
    			 * 2) There is an ISA-specific reason why SMI cannot be
    			 *    injected, and the moment when this changes can be
    			 *    intercepted.
    			 * 3) Or the SMI can be pending because
    			 *    inject_pending_event has completed the injection
    			 *    of an IRQ or NMI from the previous vmexit, and
    			 *    then we request an immediate exit to inject the
    			 *    SMI.
    			 */
    			if (vcpu->arch.smi_pending && !is_smm(vcpu))
    				if (!kvm_x86_ops->enable_smi_window(vcpu))
    					req_immediate_exit = true;
    			if (vcpu->arch.nmi_pending)
    				kvm_x86_ops->enable_nmi_window(vcpu);
    			if (kvm_cpu_has_injectable_intr(vcpu) || req_int_win)
    				kvm_x86_ops->enable_irq_window(vcpu);
    			WARN_ON(vcpu->arch.exception.pending);
    		}
    
    		if (kvm_lapic_enabled(vcpu)) {
    			update_cr8_intercept(vcpu);
    			kvm_lapic_sync_to_vapic(vcpu);
    		}
    	}
    
    	r = kvm_mmu_reload(vcpu);
    	if (unlikely(r)) {
    		goto cancel_injection;
    	}
    
    	preempt_disable();
    
    	kvm_x86_ops->prepare_guest_switch(vcpu);
    
    	/*
    	 * Disable IRQs before setting IN_GUEST_MODE.  Posted interrupt
    	 * IPI are then delayed after guest entry, which ensures that they
    	 * result in virtual interrupt delivery.
    	 */
    	local_irq_disable();
    	vcpu->mode = IN_GUEST_MODE;
    
    	srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
    
    	/*
    	 * 1) We should set ->mode before checking ->requests.  Please see
    	 * the comment in kvm_vcpu_exiting_guest_mode().
    	 *
    	 * 2) For APICv, we should set ->mode before checking PIR.ON.  This
    	 * pairs with the memory barrier implicit in pi_test_and_set_on
    	 * (see vmx_deliver_posted_interrupt).
    	 *
    	 * 3) This also orders the write to mode from any reads to the page
    	 * tables done while the VCPU is running.  Please see the comment
    	 * in kvm_flush_remote_tlbs.
    	 */
    	smp_mb__after_srcu_read_unlock();
    
    	/*
    	 * This handles the case where a posted interrupt was
    	 * notified with kvm_vcpu_kick.
    	 */
    	if (kvm_lapic_enabled(vcpu) && vcpu->arch.apicv_active)
    		kvm_x86_ops->sync_pir_to_irr(vcpu);
    
    	if (vcpu->mode == EXITING_GUEST_MODE || kvm_request_pending(vcpu)
    	    || need_resched() || signal_pending(current)) {
    		vcpu->mode = OUTSIDE_GUEST_MODE;
    		smp_wmb();
    		local_irq_enable();
    		preempt_enable();
    		vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
    		r = 1;
    		goto cancel_injection;
    	}
    
    	kvm_load_guest_xcr0(vcpu);
    
    	if (req_immediate_exit) {
    		kvm_make_request(KVM_REQ_EVENT, vcpu);
    		kvm_x86_ops->request_immediate_exit(vcpu);
    	}
    
    	trace_kvm_entry(vcpu->vcpu_id);
    	if (lapic_timer_advance_ns)
    		wait_lapic_expire(vcpu);
    	guest_enter_irqoff();
    
    	if (unlikely(vcpu->arch.switch_db_regs)) {
    		set_debugreg(0, 7);
    		set_debugreg(vcpu->arch.eff_db[0], 0);
    		set_debugreg(vcpu->arch.eff_db[1], 1);
    		set_debugreg(vcpu->arch.eff_db[2], 2);
    		set_debugreg(vcpu->arch.eff_db[3], 3);
    		set_debugreg(vcpu->arch.dr6, 6);
    		vcpu->arch.switch_db_regs &= ~KVM_DEBUGREG_RELOAD;
    	}
    
    	kvm_x86_ops->run(vcpu);
    
    	/*
    	 * Do this here before restoring debug registers on the host.  And
    	 * since we do this before handling the vmexit, a DR access vmexit
    	 * can (a) read the correct value of the debug registers, (b) set
    	 * KVM_DEBUGREG_WONT_EXIT again.
    	 */
    	if (unlikely(vcpu->arch.switch_db_regs & KVM_DEBUGREG_WONT_EXIT)) {
    		WARN_ON(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP);
    		kvm_x86_ops->sync_dirty_debug_regs(vcpu);
    		kvm_update_dr0123(vcpu);
    		kvm_update_dr6(vcpu);
    		kvm_update_dr7(vcpu);
    		vcpu->arch.switch_db_regs &= ~KVM_DEBUGREG_RELOAD;
    	}
    
    	/*
    	 * If the guest has used debug registers, at least dr7
    	 * will be disabled while returning to the host.
    	 * If we don't have active breakpoints in the host, we don't
    	 * care about the messed up debug address registers. But if
    	 * we have some of them active, restore the old state.
    	 */
    	if (hw_breakpoint_active())
    		hw_breakpoint_restore();
    
    	vcpu->arch.last_guest_tsc = kvm_read_l1_tsc(vcpu, rdtsc());
    
    	vcpu->mode = OUTSIDE_GUEST_MODE;
    	smp_wmb();
    
    	kvm_put_guest_xcr0(vcpu);
    
    	kvm_before_interrupt(vcpu);
    	kvm_x86_ops->handle_external_intr(vcpu);
    	kvm_after_interrupt(vcpu);
    
    	++vcpu->stat.exits;
    
    	guest_exit_irqoff();
    
    	local_irq_enable();
    	preempt_enable();
    
    	vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
    
    	/*
    	 * Profile KVM exit RIPs:
    	 */
    	if (unlikely(prof_on == KVM_PROFILING)) {
    		unsigned long rip = kvm_rip_read(vcpu);
    		profile_hit(KVM_PROFILING, (void *)rip);
    	}
    
    	if (unlikely(vcpu->arch.tsc_always_catchup))
    		kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
    
    	if (vcpu->arch.apic_attention)
    		kvm_lapic_sync_from_vapic(vcpu);
    
    	vcpu->arch.gpa_available = false;
    	r = kvm_x86_ops->handle_exit(vcpu);
    	return r;
    
    cancel_injection:
    	kvm_x86_ops->cancel_injection(vcpu);
    	if (unlikely(vcpu->arch.apic_attention))
    		kvm_lapic_sync_from_vapic(vcpu);
    out:
    	return r;
    }
    
    static inline int vcpu_block(struct kvm *kvm, struct kvm_vcpu *vcpu)
    {
    	if (!kvm_arch_vcpu_runnable(vcpu) &&
    	    (!kvm_x86_ops->pre_block || kvm_x86_ops->pre_block(vcpu) == 0)) {
    		srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
    		kvm_vcpu_block(vcpu);
    		vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
    
    		if (kvm_x86_ops->post_block)
    			kvm_x86_ops->post_block(vcpu);
    
    		if (!kvm_check_request(KVM_REQ_UNHALT, vcpu))
    			return 1;
    	}
    
    	kvm_apic_accept_events(vcpu);
    	switch(vcpu->arch.mp_state) {
    	case KVM_MP_STATE_HALTED:
    		vcpu->arch.pv.pv_unhalted = false;
    		vcpu->arch.mp_state =
    			KVM_MP_STATE_RUNNABLE;
    	case KVM_MP_STATE_RUNNABLE:
    		vcpu->arch.apf.halted = false;
    		break;
    	case KVM_MP_STATE_INIT_RECEIVED:
    		break;
    	default:
    		return -EINTR;
    		break;
    	}
    	return 1;
    }
    
    static inline bool kvm_vcpu_running(struct kvm_vcpu *vcpu)
    {
    	if (is_guest_mode(vcpu) && kvm_x86_ops->check_nested_events)
    		kvm_x86_ops->check_nested_events(vcpu, false);
    
    	return (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE &&
    		!vcpu->arch.apf.halted);
    }
    
    static int vcpu_run(struct kvm_vcpu *vcpu)
    {
    	int r;
    	struct kvm *kvm = vcpu->kvm;
    
    	vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
    	vcpu->arch.l1tf_flush_l1d = true;
    
    	for (;;) {
    		if (kvm_vcpu_running(vcpu)) {
    			r = vcpu_enter_guest(vcpu);
    		} else {
    			r = vcpu_block(kvm, vcpu);
    		}
    
    		if (r <= 0)
    			break;
    
    		kvm_clear_request(KVM_REQ_PENDING_TIMER, vcpu);
    		if (kvm_cpu_has_pending_timer(vcpu))
    			kvm_inject_pending_timer_irqs(vcpu);
    
    		if (dm_request_for_irq_injection(vcpu) &&
    			kvm_vcpu_ready_for_interrupt_injection(vcpu)) {
    			r = 0;
    			vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
    			++vcpu->stat.request_irq_exits;
    			break;
    		}
    
    		kvm_check_async_pf_completion(vcpu);
    
    		if (signal_pending(current)) {
    			r = -EINTR;
    			vcpu->run->exit_reason = KVM_EXIT_INTR;
    			++vcpu->stat.signal_exits;
    			break;
    		}
    		if (need_resched()) {
    			srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
    			cond_resched();
    			vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
    		}
    	}
    
    	srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
    
    	return r;
    }
    
    static inline int complete_emulated_io(struct kvm_vcpu *vcpu)
    {
    	int r;
    	vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
    	r = kvm_emulate_instruction(vcpu, EMULTYPE_NO_DECODE);
    	srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
    	if (r != EMULATE_DONE)
    		return 0;
    	return 1;
    }
    
    static int complete_emulated_pio(struct kvm_vcpu *vcpu)
    {
    	BUG_ON(!vcpu->arch.pio.count);
    
    	return complete_emulated_io(vcpu);
    }
    
    /*
     * Implements the following, as a state machine:
     *
     * read:
     *   for each fragment
     *     for each mmio piece in the fragment
     *       write gpa, len
     *       exit
     *       copy data
     *   execute insn
     *
     * write:
     *   for each fragment
     *     for each mmio piece in the fragment
     *       write gpa, len
     *       copy data
     *       exit
     */
    static int complete_emulated_mmio(struct kvm_vcpu *vcpu)
    {
    	struct kvm_run *run = vcpu->run;
    	struct kvm_mmio_fragment *frag;
    	unsigned len;
    
    	BUG_ON(!vcpu->mmio_needed);
    
    	/* Complete previous fragment */
    	frag = &vcpu->mmio_fragments[vcpu->mmio_cur_fragment];
    	len = min(8u, frag->len);
    	if (!vcpu->mmio_is_write)
    		memcpy(frag->data, run->mmio.data, len);
    
    	if (frag->len <= 8) {
    		/* Switch to the next fragment. */
    		frag++;
    		vcpu->mmio_cur_fragment++;
    	} else {
    		/* Go forward to the next mmio piece. */
    		frag->data += len;
    		frag->gpa += len;
    		frag->len -= len;
    	}
    
    	if (vcpu->mmio_cur_fragment >= vcpu->mmio_nr_fragments) {
    		vcpu->mmio_needed = 0;
    
    		/* FIXME: return into emulator if single-stepping.  */
    		if (vcpu->mmio_is_write)
    			return 1;
    		vcpu->mmio_read_completed = 1;
    		return complete_emulated_io(vcpu);
    	}
    
    	run->exit_reason = KVM_EXIT_MMIO;
    	run->mmio.phys_addr = frag->gpa;
    	if (vcpu->mmio_is_write)
    		memcpy(run->mmio.data, frag->data, min(8u, frag->len));
    	run->mmio.len = min(8u, frag->len);
    	run->mmio.is_write = vcpu->mmio_is_write;
    	vcpu->arch.complete_userspace_io = complete_emulated_mmio;
    	return 0;
    }
    
    /* Swap (qemu) user FPU context for the guest FPU context. */
    static void kvm_load_guest_fpu(struct kvm_vcpu *vcpu)
    {
    	preempt_disable();
    	copy_fpregs_to_fpstate(&vcpu->arch.user_fpu);
    	/* PKRU is separately restored in kvm_x86_ops->run.  */
    	__copy_kernel_to_fpregs(&vcpu->arch.guest_fpu.state,
    				~XFEATURE_MASK_PKRU);
    	preempt_enable();
    	trace_kvm_fpu(1);
    }
    
    /* When vcpu_run ends, restore user space FPU context. */
    static void kvm_put_guest_fpu(struct kvm_vcpu *vcpu)
    {
    	preempt_disable();
    	copy_fpregs_to_fpstate(&vcpu->arch.guest_fpu);
    	copy_kernel_to_fpregs(&vcpu->arch.user_fpu.state);
    	preempt_enable();
    	++vcpu->stat.fpu_reload;
    	trace_kvm_fpu(0);
    }
    
    int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
    {
    	int r;
    
    	vcpu_load(vcpu);
    	kvm_sigset_activate(vcpu);
    	kvm_load_guest_fpu(vcpu);
    
    	if (unlikely(vcpu->arch.mp_state == KVM_MP_STATE_UNINITIALIZED)) {
    		if (kvm_run->immediate_exit) {
    			r = -EINTR;
    			goto out;
    		}
    		kvm_vcpu_block(vcpu);
    		kvm_apic_accept_events(vcpu);
    		kvm_clear_request(KVM_REQ_UNHALT, vcpu);
    		r = -EAGAIN;
    		if (signal_pending(current)) {
    			r = -EINTR;
    			vcpu->run->exit_reason = KVM_EXIT_INTR;
    			++vcpu->stat.signal_exits;
    		}
    		goto out;
    	}
    
    	if (vcpu->run->kvm_valid_regs & ~KVM_SYNC_X86_VALID_FIELDS) {
    		r = -EINVAL;
    		goto out;
    	}
    
    	if (vcpu->run->kvm_dirty_regs) {
    		r = sync_regs(vcpu);
    		if (r != 0)
    			goto out;
    	}
    
    	/* re-sync apic's tpr */
    	if (!lapic_in_kernel(vcpu)) {
    		if (kvm_set_cr8(vcpu, kvm_run->cr8) != 0) {
    			r = -EINVAL;
    			goto out;
    		}
    	}
    
    	if (unlikely(vcpu->arch.complete_userspace_io)) {
    		int (*cui)(struct kvm_vcpu *) = vcpu->arch.complete_userspace_io;
    		vcpu->arch.complete_userspace_io = NULL;
    		r = cui(vcpu);
    		if (r <= 0)
    			goto out;
    	} else
    		WARN_ON(vcpu->arch.pio.count || vcpu->mmio_needed);
    
    	if (kvm_run->immediate_exit)
    		r = -EINTR;
    	else
    		r = vcpu_run(vcpu);
    
    out:
    	kvm_put_guest_fpu(vcpu);
    	if (vcpu->run->kvm_valid_regs)
    		store_regs(vcpu);
    	post_kvm_run_save(vcpu);
    	kvm_sigset_deactivate(vcpu);
    
    	vcpu_put(vcpu);
    	return r;
    }
    
    static void __get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
    {
    	if (vcpu->arch.emulate_regs_need_sync_to_vcpu) {
    		/*
    		 * We are here if userspace calls get_regs() in the middle of
    		 * instruction emulation. Registers state needs to be copied
    		 * back from emulation context to vcpu. Userspace shouldn't do
    		 * that usually, but some bad designed PV devices (vmware
    		 * backdoor interface) need this to work
    		 */
    		emulator_writeback_register_cache(&vcpu->arch.emulate_ctxt);
    		vcpu->arch.emulate_regs_need_sync_to_vcpu = false;
    	}
    	regs->rax = kvm_register_read(vcpu, VCPU_REGS_RAX);
    	regs->rbx = kvm_register_read(vcpu, VCPU_REGS_RBX);
    	regs->rcx = kvm_register_read(vcpu, VCPU_REGS_RCX);
    	regs->rdx = kvm_register_read(vcpu, VCPU_REGS_RDX);
    	regs->rsi = kvm_register_read(vcpu, VCPU_REGS_RSI);
    	regs->rdi = kvm_register_read(vcpu, VCPU_REGS_RDI);
    	regs->rsp = kvm_register_read(vcpu, VCPU_REGS_RSP);
    	regs->rbp = kvm_register_read(vcpu, VCPU_REGS_RBP);
    #ifdef CONFIG_X86_64
    	regs->r8 = kvm_register_read(vcpu, VCPU_REGS_R8);
    	regs->r9 = kvm_register_read(vcpu, VCPU_REGS_R9);
    	regs->r10 = kvm_register_read(vcpu, VCPU_REGS_R10);
    	regs->r11 = kvm_register_read(vcpu, VCPU_REGS_R11);
    	regs->r12 = kvm_register_read(vcpu, VCPU_REGS_R12);
    	regs->r13 = kvm_register_read(vcpu, VCPU_REGS_R13);
    	regs->r14 = kvm_register_read(vcpu, VCPU_REGS_R14);
    	regs->r15 = kvm_register_read(vcpu, VCPU_REGS_R15);
    #endif
    
    	regs->rip = kvm_rip_read(vcpu);
    	regs->rflags = kvm_get_rflags(vcpu);
    }
    
    int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
    {
    	vcpu_load(vcpu);
    	__get_regs(vcpu, regs);
    	vcpu_put(vcpu);
    	return 0;
    }
    
    static void __set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
    {
    	vcpu->arch.emulate_regs_need_sync_from_vcpu = true;
    	vcpu->arch.emulate_regs_need_sync_to_vcpu = false;
    
    	kvm_register_write(vcpu, VCPU_REGS_RAX, regs->rax);
    	kvm_register_write(vcpu, VCPU_REGS_RBX, regs->rbx);
    	kvm_register_write(vcpu, VCPU_REGS_RCX, regs->rcx);
    	kvm_register_write(vcpu, VCPU_REGS_RDX, regs->rdx);
    	kvm_register_write(vcpu, VCPU_REGS_RSI, regs->rsi);
    	kvm_register_write(vcpu, VCPU_REGS_RDI, regs->rdi);
    	kvm_register_write(vcpu, VCPU_REGS_RSP, regs->rsp);
    	kvm_register_write(vcpu, VCPU_REGS_RBP, regs->rbp);
    #ifdef CONFIG_X86_64
    	kvm_register_write(vcpu, VCPU_REGS_R8, regs->r8);
    	kvm_register_write(vcpu, VCPU_REGS_R9, regs->r9);
    	kvm_register_write(vcpu, VCPU_REGS_R10, regs->r10);
    	kvm_register_write(vcpu, VCPU_REGS_R11, regs->r11);
    	kvm_register_write(vcpu, VCPU_REGS_R12, regs->r12);
    	kvm_register_write(vcpu, VCPU_REGS_R13, regs->r13);
    	kvm_register_write(vcpu, VCPU_REGS_R14, regs->r14);
    	kvm_register_write(vcpu, VCPU_REGS_R15, regs->r15);
    #endif
    
    	kvm_rip_write(vcpu, regs->rip);
    	kvm_set_rflags(vcpu, regs->rflags | X86_EFLAGS_FIXED);
    
    	vcpu->arch.exception.pending = false;
    
    	kvm_make_request(KVM_REQ_EVENT, vcpu);
    }
    
    int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
    {
    	vcpu_load(vcpu);
    	__set_regs(vcpu, regs);
    	vcpu_put(vcpu);
    	return 0;
    }
    
    void kvm_get_cs_db_l_bits(struct kvm_vcpu *vcpu, int *db, int *l)
    {
    	struct kvm_segment cs;
    
    	kvm_get_segment(vcpu, &cs, VCPU_SREG_CS);
    	*db = cs.db;
    	*l = cs.l;
    }
    EXPORT_SYMBOL_GPL(kvm_get_cs_db_l_bits);
    
    static void __get_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
    {
    	struct desc_ptr dt;
    
    	kvm_get_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
    	kvm_get_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
    	kvm_get_segment(vcpu, &sregs->es, VCPU_SREG_ES);
    	kvm_get_segment(vcpu, &sregs->fs, VCPU_SREG_FS);
    	kvm_get_segment(vcpu, &sregs->gs, VCPU_SREG_GS);
    	kvm_get_segment(vcpu, &sregs->ss, VCPU_SREG_SS);
    
    	kvm_get_segment(vcpu, &sregs->tr, VCPU_SREG_TR);
    	kvm_get_segment(vcpu, &sregs->ldt, VCPU_SREG_LDTR);
    
    	kvm_x86_ops->get_idt(vcpu, &dt);
    	sregs->idt.limit = dt.size;
    	sregs->idt.base = dt.address;
    	kvm_x86_ops->get_gdt(vcpu, &dt);
    	sregs->gdt.limit = dt.size;
    	sregs->gdt.base = dt.address;
    
    	sregs->cr0 = kvm_read_cr0(vcpu);
    	sregs->cr2 = vcpu->arch.cr2;
    	sregs->cr3 = kvm_read_cr3(vcpu);
    	sregs->cr4 = kvm_read_cr4(vcpu);
    	sregs->cr8 = kvm_get_cr8(vcpu);
    	sregs->efer = vcpu->arch.efer;
    	sregs->apic_base = kvm_get_apic_base(vcpu);
    
    	memset(sregs->interrupt_bitmap, 0, sizeof sregs->interrupt_bitmap);
    
    	if (vcpu->arch.interrupt.injected && !vcpu->arch.interrupt.soft)
    		set_bit(vcpu->arch.interrupt.nr,
    			(unsigned long *)sregs->interrupt_bitmap);
    }
    
    int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
    				  struct kvm_sregs *sregs)
    {
    	vcpu_load(vcpu);
    	__get_sregs(vcpu, sregs);
    	vcpu_put(vcpu);
    	return 0;
    }
    
    int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
    				    struct kvm_mp_state *mp_state)
    {
    	vcpu_load(vcpu);
    
    	kvm_apic_accept_events(vcpu);
    	if (vcpu->arch.mp_state == KVM_MP_STATE_HALTED &&
    					vcpu->arch.pv.pv_unhalted)
    		mp_state->mp_state = KVM_MP_STATE_RUNNABLE;
    	else
    		mp_state->mp_state = vcpu->arch.mp_state;
    
    	vcpu_put(vcpu);
    	return 0;
    }
    
    int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
    				    struct kvm_mp_state *mp_state)
    {
    	int ret = -EINVAL;
    
    	vcpu_load(vcpu);
    
    	if (!lapic_in_kernel(vcpu) &&
    	    mp_state->mp_state != KVM_MP_STATE_RUNNABLE)
    		goto out;
    
    	/* INITs are latched while in SMM */
    	if ((is_smm(vcpu) || vcpu->arch.smi_pending) &&
    	    (mp_state->mp_state == KVM_MP_STATE_SIPI_RECEIVED ||
    	     mp_state->mp_state == KVM_MP_STATE_INIT_RECEIVED))
    		goto out;
    
    	if (mp_state->mp_state == KVM_MP_STATE_SIPI_RECEIVED) {
    		vcpu->arch.mp_state = KVM_MP_STATE_INIT_RECEIVED;
    		set_bit(KVM_APIC_SIPI, &vcpu->arch.apic->pending_events);
    	} else
    		vcpu->arch.mp_state = mp_state->mp_state;
    	kvm_make_request(KVM_REQ_EVENT, vcpu);
    
    	ret = 0;
    out:
    	vcpu_put(vcpu);
    	return ret;
    }
    
    int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int idt_index,
    		    int reason, bool has_error_code, u32 error_code)
    {
    	struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt;
    	int ret;
    
    	init_emulate_ctxt(vcpu);
    
    	ret = emulator_task_switch(ctxt, tss_selector, idt_index, reason,
    				   has_error_code, error_code);
    
    	if (ret)
    		return EMULATE_FAIL;
    
    	kvm_rip_write(vcpu, ctxt->eip);
    	kvm_set_rflags(vcpu, ctxt->eflags);
    	kvm_make_request(KVM_REQ_EVENT, vcpu);
    	return EMULATE_DONE;
    }
    EXPORT_SYMBOL_GPL(kvm_task_switch);
    
    static int kvm_valid_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
    {
    	if (!guest_cpuid_has(vcpu, X86_FEATURE_XSAVE) &&
    			(sregs->cr4 & X86_CR4_OSXSAVE))
    		return  -EINVAL;
    
    	if ((sregs->efer & EFER_LME) && (sregs->cr0 & X86_CR0_PG)) {
    		/*
    		 * When EFER.LME and CR0.PG are set, the processor is in
    		 * 64-bit mode (though maybe in a 32-bit code segment).
    		 * CR4.PAE and EFER.LMA must be set.
    		 */
    		if (!(sregs->cr4 & X86_CR4_PAE)
    		    || !(sregs->efer & EFER_LMA))
    			return -EINVAL;
    	} else {
    		/*
    		 * Not in 64-bit mode: EFER.LMA is clear and the code
    		 * segment cannot be 64-bit.
    		 */
    		if (sregs->efer & EFER_LMA || sregs->cs.l)
    			return -EINVAL;
    	}
    
    	return 0;
    }
    
    static int __set_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
    {
    	struct msr_data apic_base_msr;
    	int mmu_reset_needed = 0;
    	int cpuid_update_needed = 0;
    	int pending_vec, max_bits, idx;
    	struct desc_ptr dt;
    	int ret = -EINVAL;
    
    	if (kvm_valid_sregs(vcpu, sregs))
    		goto out;
    
    	apic_base_msr.data = sregs->apic_base;
    	apic_base_msr.host_initiated = true;
    	if (kvm_set_apic_base(vcpu, &apic_base_msr))
    		goto out;
    
    	dt.size = sregs->idt.limit;
    	dt.address = sregs->idt.base;
    	kvm_x86_ops->set_idt(vcpu, &dt);
    	dt.size = sregs->gdt.limit;
    	dt.address = sregs->gdt.base;
    	kvm_x86_ops->set_gdt(vcpu, &dt);
    
    	vcpu->arch.cr2 = sregs->cr2;
    	mmu_reset_needed |= kvm_read_cr3(vcpu) != sregs->cr3;
    	vcpu->arch.cr3 = sregs->cr3;
    	__set_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail);
    
    	kvm_set_cr8(vcpu, sregs->cr8);
    
    	mmu_reset_needed |= vcpu->arch.efer != sregs->efer;
    	kvm_x86_ops->set_efer(vcpu, sregs->efer);
    
    	mmu_reset_needed |= kvm_read_cr0(vcpu) != sregs->cr0;
    	kvm_x86_ops->set_cr0(vcpu, sregs->cr0);
    	vcpu->arch.cr0 = sregs->cr0;
    
    	mmu_reset_needed |= kvm_read_cr4(vcpu) != sregs->cr4;
    	cpuid_update_needed |= ((kvm_read_cr4(vcpu) ^ sregs->cr4) &
    				(X86_CR4_OSXSAVE | X86_CR4_PKE));
    	kvm_x86_ops->set_cr4(vcpu, sregs->cr4);
    	if (cpuid_update_needed)
    		kvm_update_cpuid(vcpu);
    
    	idx = srcu_read_lock(&vcpu->kvm->srcu);
    	if (!is_long_mode(vcpu) && is_pae(vcpu) && is_paging(vcpu)) {
    		load_pdptrs(vcpu, vcpu->arch.walk_mmu, kvm_read_cr3(vcpu));
    		mmu_reset_needed = 1;
    	}
    	srcu_read_unlock(&vcpu->kvm->srcu, idx);
    
    	if (mmu_reset_needed)
    		kvm_mmu_reset_context(vcpu);
    
    	max_bits = KVM_NR_INTERRUPTS;
    	pending_vec = find_first_bit(
    		(const unsigned long *)sregs->interrupt_bitmap, max_bits);
    	if (pending_vec < max_bits) {
    		kvm_queue_interrupt(vcpu, pending_vec, false);
    		pr_debug("Set back pending irq %d\n", pending_vec);
    	}
    
    	kvm_set_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
    	kvm_set_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
    	kvm_set_segment(vcpu, &sregs->es, VCPU_SREG_ES);
    	kvm_set_segment(vcpu, &sregs->fs, VCPU_SREG_FS);
    	kvm_set_segment(vcpu, &sregs->gs, VCPU_SREG_GS);
    	kvm_set_segment(vcpu, &sregs->ss, VCPU_SREG_SS);
    
    	kvm_set_segment(vcpu, &sregs->tr, VCPU_SREG_TR);
    	kvm_set_segment(vcpu, &sregs->ldt, VCPU_SREG_LDTR);
    
    	update_cr8_intercept(vcpu);
    
    	/* Older userspace won't unhalt the vcpu on reset. */
    	if (kvm_vcpu_is_bsp(vcpu) && kvm_rip_read(vcpu) == 0xfff0 &&
    	    sregs->cs.selector == 0xf000 && sregs->cs.base == 0xffff0000 &&
    	    !is_protmode(vcpu))
    		vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
    
    	kvm_make_request(KVM_REQ_EVENT, vcpu);
    
    	ret = 0;
    out:
    	return ret;
    }
    
    int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
    				  struct kvm_sregs *sregs)
    {
    	int ret;
    
    	vcpu_load(vcpu);
    	ret = __set_sregs(vcpu, sregs);
    	vcpu_put(vcpu);
    	return ret;
    }
    
    int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
    					struct kvm_guest_debug *dbg)
    {
    	unsigned long rflags;
    	int i, r;
    
    	vcpu_load(vcpu);
    
    	if (dbg->control & (KVM_GUESTDBG_INJECT_DB | KVM_GUESTDBG_INJECT_BP)) {
    		r = -EBUSY;
    		if (vcpu->arch.exception.pending)
    			goto out;
    		if (dbg->control & KVM_GUESTDBG_INJECT_DB)
    			kvm_queue_exception(vcpu, DB_VECTOR);
    		else
    			kvm_queue_exception(vcpu, BP_VECTOR);
    	}
    
    	/*
    	 * Read rflags as long as potentially injected trace flags are still
    	 * filtered out.
    	 */
    	rflags = kvm_get_rflags(vcpu);
    
    	vcpu->guest_debug = dbg->control;
    	if (!(vcpu->guest_debug & KVM_GUESTDBG_ENABLE))
    		vcpu->guest_debug = 0;
    
    	if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP) {
    		for (i = 0; i < KVM_NR_DB_REGS; ++i)
    			vcpu->arch.eff_db[i] = dbg->arch.debugreg[i];
    		vcpu->arch.guest_debug_dr7 = dbg->arch.debugreg[7];
    	} else {
    		for (i = 0; i < KVM_NR_DB_REGS; i++)
    			vcpu->arch.eff_db[i] = vcpu->arch.db[i];
    	}
    	kvm_update_dr7(vcpu);
    
    	if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
    		vcpu->arch.singlestep_rip = kvm_rip_read(vcpu) +
    			get_segment_base(vcpu, VCPU_SREG_CS);
    
    	/*
    	 * Trigger an rflags update that will inject or remove the trace
    	 * flags.
    	 */
    	kvm_set_rflags(vcpu, rflags);
    
    	kvm_x86_ops->update_bp_intercept(vcpu);
    
    	r = 0;
    
    out:
    	vcpu_put(vcpu);
    	return r;
    }
    
    /*
     * Translate a guest virtual address to a guest physical address.
     */
    int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
    				    struct kvm_translation *tr)
    {
    	unsigned long vaddr = tr->linear_address;
    	gpa_t gpa;
    	int idx;
    
    	vcpu_load(vcpu);
    
    	idx = srcu_read_lock(&vcpu->kvm->srcu);
    	gpa = kvm_mmu_gva_to_gpa_system(vcpu, vaddr, NULL);
    	srcu_read_unlock(&vcpu->kvm->srcu, idx);
    	tr->physical_address = gpa;
    	tr->valid = gpa != UNMAPPED_GVA;
    	tr->writeable = 1;
    	tr->usermode = 0;
    
    	vcpu_put(vcpu);
    	return 0;
    }
    
    int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
    {
    	struct fxregs_state *fxsave;
    
    	vcpu_load(vcpu);
    
    	fxsave = &vcpu->arch.guest_fpu.state.fxsave;
    	memcpy(fpu->fpr, fxsave->st_space, 128);
    	fpu->fcw = fxsave->cwd;
    	fpu->fsw = fxsave->swd;
    	fpu->ftwx = fxsave->twd;
    	fpu->last_opcode = fxsave->fop;
    	fpu->last_ip = fxsave->rip;
    	fpu->last_dp = fxsave->rdp;
    	memcpy(fpu->xmm, fxsave->xmm_space, sizeof fxsave->xmm_space);
    
    	vcpu_put(vcpu);
    	return 0;
    }
    
    int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
    {
    	struct fxregs_state *fxsave;
    
    	vcpu_load(vcpu);
    
    	fxsave = &vcpu->arch.guest_fpu.state.fxsave;
    
    	memcpy(fxsave->st_space, fpu->fpr, 128);
    	fxsave->cwd = fpu->fcw;
    	fxsave->swd = fpu->fsw;
    	fxsave->twd = fpu->ftwx;
    	fxsave->fop = fpu->last_opcode;
    	fxsave->rip = fpu->last_ip;
    	fxsave->rdp = fpu->last_dp;
    	memcpy(fxsave->xmm_space, fpu->xmm, sizeof fxsave->xmm_space);
    
    	vcpu_put(vcpu);
    	return 0;
    }
    
    static void store_regs(struct kvm_vcpu *vcpu)
    {
    	BUILD_BUG_ON(sizeof(struct kvm_sync_regs) > SYNC_REGS_SIZE_BYTES);
    
    	if (vcpu->run->kvm_valid_regs & KVM_SYNC_X86_REGS)
    		__get_regs(vcpu, &vcpu->run->s.regs.regs);
    
    	if (vcpu->run->kvm_valid_regs & KVM_SYNC_X86_SREGS)
    		__get_sregs(vcpu, &vcpu->run->s.regs.sregs);
    
    	if (vcpu->run->kvm_valid_regs & KVM_SYNC_X86_EVENTS)
    		kvm_vcpu_ioctl_x86_get_vcpu_events(
    				vcpu, &vcpu->run->s.regs.events);
    }
    
    static int sync_regs(struct kvm_vcpu *vcpu)
    {
    	if (vcpu->run->kvm_dirty_regs & ~KVM_SYNC_X86_VALID_FIELDS)
    		return -EINVAL;
    
    	if (vcpu->run->kvm_dirty_regs & KVM_SYNC_X86_REGS) {
    		__set_regs(vcpu, &vcpu->run->s.regs.regs);
    		vcpu->run->kvm_dirty_regs &= ~KVM_SYNC_X86_REGS;
    	}
    	if (vcpu->run->kvm_dirty_regs & KVM_SYNC_X86_SREGS) {
    		if (__set_sregs(vcpu, &vcpu->run->s.regs.sregs))
    			return -EINVAL;
    		vcpu->run->kvm_dirty_regs &= ~KVM_SYNC_X86_SREGS;
    	}
    	if (vcpu->run->kvm_dirty_regs & KVM_SYNC_X86_EVENTS) {
    		if (kvm_vcpu_ioctl_x86_set_vcpu_events(
    				vcpu, &vcpu->run->s.regs.events))
    			return -EINVAL;
    		vcpu->run->kvm_dirty_regs &= ~KVM_SYNC_X86_EVENTS;
    	}
    
    	return 0;
    }
    
    static void fx_init(struct kvm_vcpu *vcpu)
    {
    	fpstate_init(&vcpu->arch.guest_fpu.state);
    	if (boot_cpu_has(X86_FEATURE_XSAVES))
    		vcpu->arch.guest_fpu.state.xsave.header.xcomp_bv =
    			host_xcr0 | XSTATE_COMPACTION_ENABLED;
    
    	/*
    	 * Ensure guest xcr0 is valid for loading
    	 */
    	vcpu->arch.xcr0 = XFEATURE_MASK_FP;
    
    	vcpu->arch.cr0 |= X86_CR0_ET;
    }
    
    void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
    {
    	void *wbinvd_dirty_mask = vcpu->arch.wbinvd_dirty_mask;
    
    	kvmclock_reset(vcpu);
    
    	kvm_x86_ops->vcpu_free(vcpu);
    	free_cpumask_var(wbinvd_dirty_mask);
    }
    
    struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
    						unsigned int id)
    {
    	struct kvm_vcpu *vcpu;
    
    	if (kvm_check_tsc_unstable() && atomic_read(&kvm->online_vcpus) != 0)
    		printk_once(KERN_WARNING
    		"kvm: SMP vm created on host with unstable TSC; "
    		"guest TSC will not be reliable\n");
    
    	vcpu = kvm_x86_ops->vcpu_create(kvm, id);
    
    	return vcpu;
    }
    
    int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
    {
    	kvm_vcpu_mtrr_init(vcpu);
    	vcpu_load(vcpu);
    	kvm_vcpu_reset(vcpu, false);
    	kvm_mmu_setup(vcpu);
    	vcpu_put(vcpu);
    	return 0;
    }
    
    void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
    {
    	struct msr_data msr;
    	struct kvm *kvm = vcpu->kvm;
    
    	kvm_hv_vcpu_postcreate(vcpu);
    
    	if (mutex_lock_killable(&vcpu->mutex))
    		return;
    	vcpu_load(vcpu);
    	msr.data = 0x0;
    	msr.index = MSR_IA32_TSC;
    	msr.host_initiated = true;
    	kvm_write_tsc(vcpu, &msr);
    	vcpu_put(vcpu);
    	mutex_unlock(&vcpu->mutex);
    
    	if (!kvmclock_periodic_sync)
    		return;
    
    	schedule_delayed_work(&kvm->arch.kvmclock_sync_work,
    					KVMCLOCK_SYNC_PERIOD);
    }
    
    void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
    {
    	vcpu->arch.apf.msr_val = 0;
    
    	vcpu_load(vcpu);
    	kvm_mmu_unload(vcpu);
    	vcpu_put(vcpu);
    
    	kvm_x86_ops->vcpu_free(vcpu);
    }
    
    void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
    {
    	kvm_lapic_reset(vcpu, init_event);
    
    	vcpu->arch.hflags = 0;
    
    	vcpu->arch.smi_pending = 0;
    	vcpu->arch.smi_count = 0;
    	atomic_set(&vcpu->arch.nmi_queued, 0);
    	vcpu->arch.nmi_pending = 0;
    	vcpu->arch.nmi_injected = false;
    	kvm_clear_interrupt_queue(vcpu);
    	kvm_clear_exception_queue(vcpu);
    	vcpu->arch.exception.pending = false;
    
    	memset(vcpu->arch.db, 0, sizeof(vcpu->arch.db));
    	kvm_update_dr0123(vcpu);
    	vcpu->arch.dr6 = DR6_INIT;
    	kvm_update_dr6(vcpu);
    	vcpu->arch.dr7 = DR7_FIXED_1;
    	kvm_update_dr7(vcpu);
    
    	vcpu->arch.cr2 = 0;
    
    	kvm_make_request(KVM_REQ_EVENT, vcpu);
    	vcpu->arch.apf.msr_val = 0;
    	vcpu->arch.st.msr_val = 0;
    
    	kvmclock_reset(vcpu);
    
    	kvm_clear_async_pf_completion_queue(vcpu);
    	kvm_async_pf_hash_reset(vcpu);
    	vcpu->arch.apf.halted = false;
    
    	if (kvm_mpx_supported()) {
    		void *mpx_state_buffer;
    
    		/*
    		 * To avoid have the INIT path from kvm_apic_has_events() that be
    		 * called with loaded FPU and does not let userspace fix the state.
    		 */
    		if (init_event)
    			kvm_put_guest_fpu(vcpu);
    		mpx_state_buffer = get_xsave_addr(&vcpu->arch.guest_fpu.state.xsave,
    					XFEATURE_MASK_BNDREGS);
    		if (mpx_state_buffer)
    			memset(mpx_state_buffer, 0, sizeof(struct mpx_bndreg_state));
    		mpx_state_buffer = get_xsave_addr(&vcpu->arch.guest_fpu.state.xsave,
    					XFEATURE_MASK_BNDCSR);
    		if (mpx_state_buffer)
    			memset(mpx_state_buffer, 0, sizeof(struct mpx_bndcsr));
    		if (init_event)
    			kvm_load_guest_fpu(vcpu);
    	}
    
    	if (!init_event) {
    		kvm_pmu_reset(vcpu);
    		vcpu->arch.smbase = 0x30000;
    
    		vcpu->arch.msr_platform_info = MSR_PLATFORM_INFO_CPUID_FAULT;
    		vcpu->arch.msr_misc_features_enables = 0;
    
    		vcpu->arch.xcr0 = XFEATURE_MASK_FP;
    	}
    
    	memset(vcpu->arch.regs, 0, sizeof(vcpu->arch.regs));
    	vcpu->arch.regs_avail = ~0;
    	vcpu->arch.regs_dirty = ~0;
    
    	vcpu->arch.ia32_xss = 0;
    
    	kvm_x86_ops->vcpu_reset(vcpu, init_event);
    }
    
    void kvm_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector)
    {
    	struct kvm_segment cs;
    
    	kvm_get_segment(vcpu, &cs, VCPU_SREG_CS);
    	cs.selector = vector << 8;
    	cs.base = vector << 12;
    	kvm_set_segment(vcpu, &cs, VCPU_SREG_CS);
    	kvm_rip_write(vcpu, 0);
    }
    
    int kvm_arch_hardware_enable(void)
    {
    	struct kvm *kvm;
    	struct kvm_vcpu *vcpu;
    	int i;
    	int ret;
    	u64 local_tsc;
    	u64 max_tsc = 0;
    	bool stable, backwards_tsc = false;
    
    	kvm_shared_msr_cpu_online();
    	ret = kvm_x86_ops->hardware_enable();
    	if (ret != 0)
    		return ret;
    
    	local_tsc = rdtsc();
    	stable = !kvm_check_tsc_unstable();
    	list_for_each_entry(kvm, &vm_list, vm_list) {
    		kvm_for_each_vcpu(i, vcpu, kvm) {
    			if (!stable && vcpu->cpu == smp_processor_id())
    				kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
    			if (stable && vcpu->arch.last_host_tsc > local_tsc) {
    				backwards_tsc = true;
    				if (vcpu->arch.last_host_tsc > max_tsc)
    					max_tsc = vcpu->arch.last_host_tsc;
    			}
    		}
    	}
    
    	/*
    	 * Sometimes, even reliable TSCs go backwards.  This happens on
    	 * platforms that reset TSC during suspend or hibernate actions, but
    	 * maintain synchronization.  We must compensate.  Fortunately, we can
    	 * detect that condition here, which happens early in CPU bringup,
    	 * before any KVM threads can be running.  Unfortunately, we can't
    	 * bring the TSCs fully up to date with real time, as we aren't yet far
    	 * enough into CPU bringup that we know how much real time has actually
    	 * elapsed; our helper function, ktime_get_boot_ns() will be using boot
    	 * variables that haven't been updated yet.
    	 *
    	 * So we simply find the maximum observed TSC above, then record the
    	 * adjustment to TSC in each VCPU.  When the VCPU later gets loaded,
    	 * the adjustment will be applied.  Note that we accumulate
    	 * adjustments, in case multiple suspend cycles happen before some VCPU
    	 * gets a chance to run again.  In the event that no KVM threads get a
    	 * chance to run, we will miss the entire elapsed period, as we'll have
    	 * reset last_host_tsc, so VCPUs will not have the TSC adjusted and may
    	 * loose cycle time.  This isn't too big a deal, since the loss will be
    	 * uniform across all VCPUs (not to mention the scenario is extremely
    	 * unlikely). It is possible that a second hibernate recovery happens
    	 * much faster than a first, causing the observed TSC here to be
    	 * smaller; this would require additional padding adjustment, which is
    	 * why we set last_host_tsc to the local tsc observed here.
    	 *
    	 * N.B. - this code below runs only on platforms with reliable TSC,
    	 * as that is the only way backwards_tsc is set above.  Also note
    	 * that this runs for ALL vcpus, which is not a bug; all VCPUs should
    	 * have the same delta_cyc adjustment applied if backwards_tsc
    	 * is detected.  Note further, this adjustment is only done once,
    	 * as we reset last_host_tsc on all VCPUs to stop this from being
    	 * called multiple times (one for each physical CPU bringup).
    	 *
    	 * Platforms with unreliable TSCs don't have to deal with this, they
    	 * will be compensated by the logic in vcpu_load, which sets the TSC to
    	 * catchup mode.  This will catchup all VCPUs to real time, but cannot
    	 * guarantee that they stay in perfect synchronization.
    	 */
    	if (backwards_tsc) {
    		u64 delta_cyc = max_tsc - local_tsc;
    		list_for_each_entry(kvm, &vm_list, vm_list) {
    			kvm->arch.backwards_tsc_observed = true;
    			kvm_for_each_vcpu(i, vcpu, kvm) {
    				vcpu->arch.tsc_offset_adjustment += delta_cyc;
    				vcpu->arch.last_host_tsc = local_tsc;
    				kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
    			}
    
    			/*
    			 * We have to disable TSC offset matching.. if you were
    			 * booting a VM while issuing an S4 host suspend....
    			 * you may have some problem.  Solving this issue is
    			 * left as an exercise to the reader.
    			 */
    			kvm->arch.last_tsc_nsec = 0;
    			kvm->arch.last_tsc_write = 0;
    		}
    
    	}
    	return 0;
    }
    
    void kvm_arch_hardware_disable(void)
    {
    	kvm_x86_ops->hardware_disable();
    	drop_user_return_notifiers();
    }
    
    int kvm_arch_hardware_setup(void)
    {
    	int r;
    
    	r = kvm_x86_ops->hardware_setup();
    	if (r != 0)
    		return r;
    
    	if (kvm_has_tsc_control) {
    		/*
    		 * Make sure the user can only configure tsc_khz values that
    		 * fit into a signed integer.
    		 * A min value is not calculated because it will always
    		 * be 1 on all machines.
    		 */
    		u64 max = min(0x7fffffffULL,
    			      __scale_tsc(kvm_max_tsc_scaling_ratio, tsc_khz));
    		kvm_max_guest_tsc_khz = max;
    
    		kvm_default_tsc_scaling_ratio = 1ULL << kvm_tsc_scaling_ratio_frac_bits;
    	}
    
    	kvm_init_msr_list();
    	return 0;
    }
    
    void kvm_arch_hardware_unsetup(void)
    {
    	kvm_x86_ops->hardware_unsetup();
    }
    
    void kvm_arch_check_processor_compat(void *rtn)
    {
    	kvm_x86_ops->check_processor_compatibility(rtn);
    }
    
    bool kvm_vcpu_is_reset_bsp(struct kvm_vcpu *vcpu)
    {
    	return vcpu->kvm->arch.bsp_vcpu_id == vcpu->vcpu_id;
    }
    EXPORT_SYMBOL_GPL(kvm_vcpu_is_reset_bsp);
    
    bool kvm_vcpu_is_bsp(struct kvm_vcpu *vcpu)
    {
    	return (vcpu->arch.apic_base & MSR_IA32_APICBASE_BSP) != 0;
    }
    
    struct static_key kvm_no_apic_vcpu __read_mostly;
    EXPORT_SYMBOL_GPL(kvm_no_apic_vcpu);
    
    int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
    {
    	struct page *page;
    	int r;
    
    	vcpu->arch.apicv_active = kvm_x86_ops->get_enable_apicv(vcpu);
    	vcpu->arch.emulate_ctxt.ops = &emulate_ops;
    	if (!irqchip_in_kernel(vcpu->kvm) || kvm_vcpu_is_reset_bsp(vcpu))
    		vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
    	else
    		vcpu->arch.mp_state = KVM_MP_STATE_UNINITIALIZED;
    
    	page = alloc_page(GFP_KERNEL | __GFP_ZERO);
    	if (!page) {
    		r = -ENOMEM;
    		goto fail;
    	}
    	vcpu->arch.pio_data = page_address(page);
    
    	kvm_set_tsc_khz(vcpu, max_tsc_khz);
    
    	r = kvm_mmu_create(vcpu);
    	if (r < 0)
    		goto fail_free_pio_data;
    
    	if (irqchip_in_kernel(vcpu->kvm)) {
    		r = kvm_create_lapic(vcpu);
    		if (r < 0)
    			goto fail_mmu_destroy;
    	} else
    		static_key_slow_inc(&kvm_no_apic_vcpu);
    
    	vcpu->arch.mce_banks = kzalloc(KVM_MAX_MCE_BANKS * sizeof(u64) * 4,
    				       GFP_KERNEL);
    	if (!vcpu->arch.mce_banks) {
    		r = -ENOMEM;
    		goto fail_free_lapic;
    	}
    	vcpu->arch.mcg_cap = KVM_MAX_MCE_BANKS;
    
    	if (!zalloc_cpumask_var(&vcpu->arch.wbinvd_dirty_mask, GFP_KERNEL)) {
    		r = -ENOMEM;
    		goto fail_free_mce_banks;
    	}
    
    	fx_init(vcpu);
    
    	vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
    
    	vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
    
    	vcpu->arch.pat = MSR_IA32_CR_PAT_DEFAULT;
    
    	kvm_async_pf_hash_reset(vcpu);
    	kvm_pmu_init(vcpu);
    
    	vcpu->arch.pending_external_vector = -1;
    	vcpu->arch.preempted_in_kernel = false;
    
    	kvm_hv_vcpu_init(vcpu);
    
    	return 0;
    
    fail_free_mce_banks:
    	kfree(vcpu->arch.mce_banks);
    fail_free_lapic:
    	kvm_free_lapic(vcpu);
    fail_mmu_destroy:
    	kvm_mmu_destroy(vcpu);
    fail_free_pio_data:
    	free_page((unsigned long)vcpu->arch.pio_data);
    fail:
    	return r;
    }
    
    void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
    {
    	int idx;
    
    	kvm_hv_vcpu_uninit(vcpu);
    	kvm_pmu_destroy(vcpu);
    	kfree(vcpu->arch.mce_banks);
    	kvm_free_lapic(vcpu);
    	idx = srcu_read_lock(&vcpu->kvm->srcu);
    	kvm_mmu_destroy(vcpu);
    	srcu_read_unlock(&vcpu->kvm->srcu, idx);
    	free_page((unsigned long)vcpu->arch.pio_data);
    	if (!lapic_in_kernel(vcpu))
    		static_key_slow_dec(&kvm_no_apic_vcpu);
    }
    
    void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)
    {
    	vcpu->arch.l1tf_flush_l1d = true;
    	kvm_x86_ops->sched_in(vcpu, cpu);
    }
    
    int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
    {
    	if (type)
    		return -EINVAL;
    
    	INIT_HLIST_HEAD(&kvm->arch.mask_notifier_list);
    	INIT_LIST_HEAD(&kvm->arch.active_mmu_pages);
    	INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages);
    	INIT_LIST_HEAD(&kvm->arch.assigned_dev_head);
    	atomic_set(&kvm->arch.noncoherent_dma_count, 0);
    
    	/* Reserve bit 0 of irq_sources_bitmap for userspace irq source */
    	set_bit(KVM_USERSPACE_IRQ_SOURCE_ID, &kvm->arch.irq_sources_bitmap);
    	/* Reserve bit 1 of irq_sources_bitmap for irqfd-resampler */
    	set_bit(KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID,
    		&kvm->arch.irq_sources_bitmap);
    
    	raw_spin_lock_init(&kvm->arch.tsc_write_lock);
    	mutex_init(&kvm->arch.apic_map_lock);
    	spin_lock_init(&kvm->arch.pvclock_gtod_sync_lock);
    
    	kvm->arch.kvmclock_offset = -ktime_get_boot_ns();
    	pvclock_update_vm_gtod_copy(kvm);
    
    	kvm->arch.guest_can_read_msr_platform_info = true;
    
    	INIT_DELAYED_WORK(&kvm->arch.kvmclock_update_work, kvmclock_update_fn);
    	INIT_DELAYED_WORK(&kvm->arch.kvmclock_sync_work, kvmclock_sync_fn);
    
    	kvm_hv_init_vm(kvm);
    	kvm_page_track_init(kvm);
    	kvm_mmu_init_vm(kvm);
    
    	if (kvm_x86_ops->vm_init)
    		return kvm_x86_ops->vm_init(kvm);
    
    	return 0;
    }
    
    static void kvm_unload_vcpu_mmu(struct kvm_vcpu *vcpu)
    {
    	vcpu_load(vcpu);
    	kvm_mmu_unload(vcpu);
    	vcpu_put(vcpu);
    }
    
    static void kvm_free_vcpus(struct kvm *kvm)
    {
    	unsigned int i;
    	struct kvm_vcpu *vcpu;
    
    	/*
    	 * Unpin any mmu pages first.
    	 */
    	kvm_for_each_vcpu(i, vcpu, kvm) {
    		kvm_clear_async_pf_completion_queue(vcpu);
    		kvm_unload_vcpu_mmu(vcpu);
    	}
    	kvm_for_each_vcpu(i, vcpu, kvm)
    		kvm_arch_vcpu_free(vcpu);
    
    	mutex_lock(&kvm->lock);
    	for (i = 0; i < atomic_read(&kvm->online_vcpus); i++)
    		kvm->vcpus[i] = NULL;
    
    	atomic_set(&kvm->online_vcpus, 0);
    	mutex_unlock(&kvm->lock);
    }
    
    void kvm_arch_sync_events(struct kvm *kvm)
    {
    	cancel_delayed_work_sync(&kvm->arch.kvmclock_sync_work);
    	cancel_delayed_work_sync(&kvm->arch.kvmclock_update_work);
    	kvm_free_pit(kvm);
    }
    
    int __x86_set_memory_region(struct kvm *kvm, int id, gpa_t gpa, u32 size)
    {
    	int i, r;
    	unsigned long hva;
    	struct kvm_memslots *slots = kvm_memslots(kvm);
    	struct kvm_memory_slot *slot, old;
    
    	/* Called with kvm->slots_lock held.  */
    	if (WARN_ON(id >= KVM_MEM_SLOTS_NUM))
    		return -EINVAL;
    
    	slot = id_to_memslot(slots, id);
    	if (size) {
    		if (slot->npages)
    			return -EEXIST;
    
    		/*
    		 * MAP_SHARED to prevent internal slot pages from being moved
    		 * by fork()/COW.
    		 */
    		hva = vm_mmap(NULL, 0, size, PROT_READ | PROT_WRITE,
    			      MAP_SHARED | MAP_ANONYMOUS, 0);
    		if (IS_ERR((void *)hva))
    			return PTR_ERR((void *)hva);
    	} else {
    		if (!slot->npages)
    			return 0;
    
    		hva = 0;
    	}
    
    	old = *slot;
    	for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
    		struct kvm_userspace_memory_region m;
    
    		m.slot = id | (i << 16);
    		m.flags = 0;
    		m.guest_phys_addr = gpa;
    		m.userspace_addr = hva;
    		m.memory_size = size;
    		r = __kvm_set_memory_region(kvm, &m);
    		if (r < 0)
    			return r;
    	}
    
    	if (!size)
    		vm_munmap(old.userspace_addr, old.npages * PAGE_SIZE);
    
    	return 0;
    }
    EXPORT_SYMBOL_GPL(__x86_set_memory_region);
    
    int x86_set_memory_region(struct kvm *kvm, int id, gpa_t gpa, u32 size)
    {
    	int r;
    
    	mutex_lock(&kvm->slots_lock);
    	r = __x86_set_memory_region(kvm, id, gpa, size);
    	mutex_unlock(&kvm->slots_lock);
    
    	return r;
    }
    EXPORT_SYMBOL_GPL(x86_set_memory_region);
    
    void kvm_arch_destroy_vm(struct kvm *kvm)
    {
    	if (current->mm == kvm->mm) {
    		/*
    		 * Free memory regions allocated on behalf of userspace,
    		 * unless the the memory map has changed due to process exit
    		 * or fd copying.
    		 */
    		x86_set_memory_region(kvm, APIC_ACCESS_PAGE_PRIVATE_MEMSLOT, 0, 0);
    		x86_set_memory_region(kvm, IDENTITY_PAGETABLE_PRIVATE_MEMSLOT, 0, 0);
    		x86_set_memory_region(kvm, TSS_PRIVATE_MEMSLOT, 0, 0);
    	}
    	if (kvm_x86_ops->vm_destroy)
    		kvm_x86_ops->vm_destroy(kvm);
    	kvm_pic_destroy(kvm);
    	kvm_ioapic_destroy(kvm);
    	kvm_free_vcpus(kvm);
    	kvfree(rcu_dereference_check(kvm->arch.apic_map, 1));
    	kvm_mmu_uninit_vm(kvm);
    	kvm_page_track_cleanup(kvm);
    	kvm_hv_destroy_vm(kvm);
    }
    
    void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
    			   struct kvm_memory_slot *dont)
    {
    	int i;
    
    	for (i = 0; i < KVM_NR_PAGE_SIZES; ++i) {
    		if (!dont || free->arch.rmap[i] != dont->arch.rmap[i]) {
    			kvfree(free->arch.rmap[i]);
    			free->arch.rmap[i] = NULL;
    		}
    		if (i == 0)
    			continue;
    
    		if (!dont || free->arch.lpage_info[i - 1] !=
    			     dont->arch.lpage_info[i - 1]) {
    			kvfree(free->arch.lpage_info[i - 1]);
    			free->arch.lpage_info[i - 1] = NULL;
    		}
    	}
    
    	kvm_page_track_free_memslot(free, dont);
    }
    
    int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
    			    unsigned long npages)
    {
    	int i;
    
    	for (i = 0; i < KVM_NR_PAGE_SIZES; ++i) {
    		struct kvm_lpage_info *linfo;
    		unsigned long ugfn;
    		int lpages;
    		int level = i + 1;
    
    		lpages = gfn_to_index(slot->base_gfn + npages - 1,
    				      slot->base_gfn, level) + 1;
    
    		slot->arch.rmap[i] =
    			kvcalloc(lpages, sizeof(*slot->arch.rmap[i]),
    				 GFP_KERNEL);
    		if (!slot->arch.rmap[i])
    			goto out_free;
    		if (i == 0)
    			continue;
    
    		linfo = kvcalloc(lpages, sizeof(*linfo), GFP_KERNEL);
    		if (!linfo)
    			goto out_free;
    
    		slot->arch.lpage_info[i - 1] = linfo;
    
    		if (slot->base_gfn & (KVM_PAGES_PER_HPAGE(level) - 1))
    			linfo[0].disallow_lpage = 1;
    		if ((slot->base_gfn + npages) & (KVM_PAGES_PER_HPAGE(level) - 1))
    			linfo[lpages - 1].disallow_lpage = 1;
    		ugfn = slot->userspace_addr >> PAGE_SHIFT;
    		/*
    		 * If the gfn and userspace address are not aligned wrt each
    		 * other, or if explicitly asked to, disable large page
    		 * support for this slot
    		 */
    		if ((slot->base_gfn ^ ugfn) & (KVM_PAGES_PER_HPAGE(level) - 1) ||
    		    !kvm_largepages_enabled()) {
    			unsigned long j;
    
    			for (j = 0; j < lpages; ++j)
    				linfo[j].disallow_lpage = 1;
    		}
    	}
    
    	if (kvm_page_track_create_memslot(slot, npages))
    		goto out_free;
    
    	return 0;
    
    out_free:
    	for (i = 0; i < KVM_NR_PAGE_SIZES; ++i) {
    		kvfree(slot->arch.rmap[i]);
    		slot->arch.rmap[i] = NULL;
    		if (i == 0)
    			continue;
    
    		kvfree(slot->arch.lpage_info[i - 1]);
    		slot->arch.lpage_info[i - 1] = NULL;
    	}
    	return -ENOMEM;
    }
    
    void kvm_arch_memslots_updated(struct kvm *kvm, struct kvm_memslots *slots)
    {
    	/*
    	 * memslots->generation has been incremented.
    	 * mmio generation may have reached its maximum value.
    	 */
    	kvm_mmu_invalidate_mmio_sptes(kvm, slots);
    }
    
    int kvm_arch_prepare_memory_region(struct kvm *kvm,
    				struct kvm_memory_slot *memslot,
    				const struct kvm_userspace_memory_region *mem,
    				enum kvm_mr_change change)
    {
    	return 0;
    }
    
    static void kvm_mmu_slot_apply_flags(struct kvm *kvm,
    				     struct kvm_memory_slot *new)
    {
    	/* Still write protect RO slot */
    	if (new->flags & KVM_MEM_READONLY) {
    		kvm_mmu_slot_remove_write_access(kvm, new);
    		return;
    	}
    
    	/*
    	 * Call kvm_x86_ops dirty logging hooks when they are valid.
    	 *
    	 * kvm_x86_ops->slot_disable_log_dirty is called when:
    	 *
    	 *  - KVM_MR_CREATE with dirty logging is disabled
    	 *  - KVM_MR_FLAGS_ONLY with dirty logging is disabled in new flag
    	 *
    	 * The reason is, in case of PML, we need to set D-bit for any slots
    	 * with dirty logging disabled in order to eliminate unnecessary GPA
    	 * logging in PML buffer (and potential PML buffer full VMEXT). This
    	 * guarantees leaving PML enabled during guest's lifetime won't have
    	 * any additonal overhead from PML when guest is running with dirty
    	 * logging disabled for memory slots.
    	 *
    	 * kvm_x86_ops->slot_enable_log_dirty is called when switching new slot
    	 * to dirty logging mode.
    	 *
    	 * If kvm_x86_ops dirty logging hooks are invalid, use write protect.
    	 *
    	 * In case of write protect:
    	 *
    	 * Write protect all pages for dirty logging.
    	 *
    	 * All the sptes including the large sptes which point to this
    	 * slot are set to readonly. We can not create any new large
    	 * spte on this slot until the end of the logging.
    	 *
    	 * See the comments in fast_page_fault().
    	 */
    	if (new->flags & KVM_MEM_LOG_DIRTY_PAGES) {
    		if (kvm_x86_ops->slot_enable_log_dirty)
    			kvm_x86_ops->slot_enable_log_dirty(kvm, new);
    		else
    			kvm_mmu_slot_remove_write_access(kvm, new);
    	} else {
    		if (kvm_x86_ops->slot_disable_log_dirty)
    			kvm_x86_ops->slot_disable_log_dirty(kvm, new);
    	}
    }
    
    void kvm_arch_commit_memory_region(struct kvm *kvm,
    				const struct kvm_userspace_memory_region *mem,
    				const struct kvm_memory_slot *old,
    				const struct kvm_memory_slot *new,
    				enum kvm_mr_change change)
    {
    	int nr_mmu_pages = 0;
    
    	if (!kvm->arch.n_requested_mmu_pages)
    		nr_mmu_pages = kvm_mmu_calculate_mmu_pages(kvm);
    
    	if (nr_mmu_pages)
    		kvm_mmu_change_mmu_pages(kvm, nr_mmu_pages);
    
    	/*
    	 * Dirty logging tracks sptes in 4k granularity, meaning that large
    	 * sptes have to be split.  If live migration is successful, the guest
    	 * in the source machine will be destroyed and large sptes will be
    	 * created in the destination. However, if the guest continues to run
    	 * in the source machine (for example if live migration fails), small
    	 * sptes will remain around and cause bad performance.
    	 *
    	 * Scan sptes if dirty logging has been stopped, dropping those
    	 * which can be collapsed into a single large-page spte.  Later
    	 * page faults will create the large-page sptes.
    	 */
    	if ((change != KVM_MR_DELETE) &&
    		(old->flags & KVM_MEM_LOG_DIRTY_PAGES) &&
    		!(new->flags & KVM_MEM_LOG_DIRTY_PAGES))
    		kvm_mmu_zap_collapsible_sptes(kvm, new);
    
    	/*
    	 * Set up write protection and/or dirty logging for the new slot.
    	 *
    	 * For KVM_MR_DELETE and KVM_MR_MOVE, the shadow pages of old slot have
    	 * been zapped so no dirty logging staff is needed for old slot. For
    	 * KVM_MR_FLAGS_ONLY, the old slot is essentially the same one as the
    	 * new and it's also covered when dealing with the new slot.
    	 *
    	 * FIXME: const-ify all uses of struct kvm_memory_slot.
    	 */
    	if (change != KVM_MR_DELETE)
    		kvm_mmu_slot_apply_flags(kvm, (struct kvm_memory_slot *) new);
    }
    
    void kvm_arch_flush_shadow_all(struct kvm *kvm)
    {
    	kvm_mmu_invalidate_zap_all_pages(kvm);
    }
    
    void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
    				   struct kvm_memory_slot *slot)
    {
    	kvm_page_track_flush_slot(kvm, slot);
    }
    
    static inline bool kvm_guest_apic_has_interrupt(struct kvm_vcpu *vcpu)
    {
    	return (is_guest_mode(vcpu) &&
    			kvm_x86_ops->guest_apic_has_interrupt &&
    			kvm_x86_ops->guest_apic_has_interrupt(vcpu));
    }
    
    static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu)
    {
    	if (!list_empty_careful(&vcpu->async_pf.done))
    		return true;
    
    	if (kvm_apic_has_events(vcpu))
    		return true;
    
    	if (vcpu->arch.pv.pv_unhalted)
    		return true;
    
    	if (vcpu->arch.exception.pending)
    		return true;
    
    	if (kvm_test_request(KVM_REQ_NMI, vcpu) ||
    	    (vcpu->arch.nmi_pending &&
    	     kvm_x86_ops->nmi_allowed(vcpu)))
    		return true;
    
    	if (kvm_test_request(KVM_REQ_SMI, vcpu) ||
    	    (vcpu->arch.smi_pending && !is_smm(vcpu)))
    		return true;
    
    	if (kvm_arch_interrupt_allowed(vcpu) &&
    	    (kvm_cpu_has_interrupt(vcpu) ||
    	    kvm_guest_apic_has_interrupt(vcpu)))
    		return true;
    
    	if (kvm_hv_has_stimer_pending(vcpu))
    		return true;
    
    	return false;
    }
    
    int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
    {
    	return kvm_vcpu_running(vcpu) || kvm_vcpu_has_events(vcpu);
    }
    
    bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu)
    {
    	return vcpu->arch.preempted_in_kernel;
    }
    
    int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
    {
    	return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
    }
    
    int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu)
    {
    	return kvm_x86_ops->interrupt_allowed(vcpu);
    }
    
    unsigned long kvm_get_linear_rip(struct kvm_vcpu *vcpu)
    {
    	if (is_64_bit_mode(vcpu))
    		return kvm_rip_read(vcpu);
    	return (u32)(get_segment_base(vcpu, VCPU_SREG_CS) +
    		     kvm_rip_read(vcpu));
    }
    EXPORT_SYMBOL_GPL(kvm_get_linear_rip);
    
    bool kvm_is_linear_rip(struct kvm_vcpu *vcpu, unsigned long linear_rip)
    {
    	return kvm_get_linear_rip(vcpu) == linear_rip;
    }
    EXPORT_SYMBOL_GPL(kvm_is_linear_rip);
    
    unsigned long kvm_get_rflags(struct kvm_vcpu *vcpu)
    {
    	unsigned long rflags;
    
    	rflags = kvm_x86_ops->get_rflags(vcpu);
    	if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
    		rflags &= ~X86_EFLAGS_TF;
    	return rflags;
    }
    EXPORT_SYMBOL_GPL(kvm_get_rflags);
    
    static void __kvm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
    {
    	if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP &&
    	    kvm_is_linear_rip(vcpu, vcpu->arch.singlestep_rip))
    		rflags |= X86_EFLAGS_TF;
    	kvm_x86_ops->set_rflags(vcpu, rflags);
    }
    
    void kvm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
    {
    	__kvm_set_rflags(vcpu, rflags);
    	kvm_make_request(KVM_REQ_EVENT, vcpu);
    }
    EXPORT_SYMBOL_GPL(kvm_set_rflags);
    
    void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work)
    {
    	int r;
    
    	if ((vcpu->arch.mmu.direct_map != work->arch.direct_map) ||
    	      work->wakeup_all)
    		return;
    
    	r = kvm_mmu_reload(vcpu);
    	if (unlikely(r))
    		return;
    
    	if (!vcpu->arch.mmu.direct_map &&
    	      work->arch.cr3 != vcpu->arch.mmu.get_cr3(vcpu))
    		return;
    
    	vcpu->arch.mmu.page_fault(vcpu, work->gva, 0, true);
    }
    
    static inline u32 kvm_async_pf_hash_fn(gfn_t gfn)
    {
    	return hash_32(gfn & 0xffffffff, order_base_2(ASYNC_PF_PER_VCPU));
    }
    
    static inline u32 kvm_async_pf_next_probe(u32 key)
    {
    	return (key + 1) & (roundup_pow_of_two(ASYNC_PF_PER_VCPU) - 1);
    }
    
    static void kvm_add_async_pf_gfn(struct kvm_vcpu *vcpu, gfn_t gfn)
    {
    	u32 key = kvm_async_pf_hash_fn(gfn);
    
    	while (vcpu->arch.apf.gfns[key] != ~0)
    		key = kvm_async_pf_next_probe(key);
    
    	vcpu->arch.apf.gfns[key] = gfn;
    }
    
    static u32 kvm_async_pf_gfn_slot(struct kvm_vcpu *vcpu, gfn_t gfn)
    {
    	int i;
    	u32 key = kvm_async_pf_hash_fn(gfn);
    
    	for (i = 0; i < roundup_pow_of_two(ASYNC_PF_PER_VCPU) &&
    		     (vcpu->arch.apf.gfns[key] != gfn &&
    		      vcpu->arch.apf.gfns[key] != ~0); i++)
    		key = kvm_async_pf_next_probe(key);
    
    	return key;
    }
    
    bool kvm_find_async_pf_gfn(struct kvm_vcpu *vcpu, gfn_t gfn)
    {
    	return vcpu->arch.apf.gfns[kvm_async_pf_gfn_slot(vcpu, gfn)] == gfn;
    }
    
    static void kvm_del_async_pf_gfn(struct kvm_vcpu *vcpu, gfn_t gfn)
    {
    	u32 i, j, k;
    
    	i = j = kvm_async_pf_gfn_slot(vcpu, gfn);
    	while (true) {
    		vcpu->arch.apf.gfns[i] = ~0;
    		do {
    			j = kvm_async_pf_next_probe(j);
    			if (vcpu->arch.apf.gfns[j] == ~0)
    				return;
    			k = kvm_async_pf_hash_fn(vcpu->arch.apf.gfns[j]);
    			/*
    			 * k lies cyclically in ]i,j]
    			 * |    i.k.j |
    			 * |....j i.k.| or  |.k..j i...|
    			 */
    		} while ((i <= j) ? (i < k && k <= j) : (i < k || k <= j));
    		vcpu->arch.apf.gfns[i] = vcpu->arch.apf.gfns[j];
    		i = j;
    	}
    }
    
    static int apf_put_user(struct kvm_vcpu *vcpu, u32 val)
    {
    
    	return kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.apf.data, &val,
    				      sizeof(val));
    }
    
    static int apf_get_user(struct kvm_vcpu *vcpu, u32 *val)
    {
    
    	return kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.apf.data, val,
    				      sizeof(u32));
    }
    
    void kvm_arch_async_page_not_present(struct kvm_vcpu *vcpu,
    				     struct kvm_async_pf *work)
    {
    	struct x86_exception fault;
    
    	trace_kvm_async_pf_not_present(work->arch.token, work->gva);
    	kvm_add_async_pf_gfn(vcpu, work->arch.gfn);
    
    	if (!(vcpu->arch.apf.msr_val & KVM_ASYNC_PF_ENABLED) ||
    	    (vcpu->arch.apf.send_user_only &&
    	     kvm_x86_ops->get_cpl(vcpu) == 0))
    		kvm_make_request(KVM_REQ_APF_HALT, vcpu);
    	else if (!apf_put_user(vcpu, KVM_PV_REASON_PAGE_NOT_PRESENT)) {
    		fault.vector = PF_VECTOR;
    		fault.error_code_valid = true;
    		fault.error_code = 0;
    		fault.nested_page_fault = false;
    		fault.address = work->arch.token;
    		fault.async_page_fault = true;
    		kvm_inject_page_fault(vcpu, &fault);
    	}
    }
    
    void kvm_arch_async_page_present(struct kvm_vcpu *vcpu,
    				 struct kvm_async_pf *work)
    {
    	struct x86_exception fault;
    	u32 val;
    
    	if (work->wakeup_all)
    		work->arch.token = ~0; /* broadcast wakeup */
    	else
    		kvm_del_async_pf_gfn(vcpu, work->arch.gfn);
    	trace_kvm_async_pf_ready(work->arch.token, work->gva);
    
    	if (vcpu->arch.apf.msr_val & KVM_ASYNC_PF_ENABLED &&
    	    !apf_get_user(vcpu, &val)) {
    		if (val == KVM_PV_REASON_PAGE_NOT_PRESENT &&
    		    vcpu->arch.exception.pending &&
    		    vcpu->arch.exception.nr == PF_VECTOR &&
    		    !apf_put_user(vcpu, 0)) {
    			vcpu->arch.exception.injected = false;
    			vcpu->arch.exception.pending = false;
    			vcpu->arch.exception.nr = 0;
    			vcpu->arch.exception.has_error_code = false;
    			vcpu->arch.exception.error_code = 0;
    		} else if (!apf_put_user(vcpu, KVM_PV_REASON_PAGE_READY)) {
    			fault.vector = PF_VECTOR;
    			fault.error_code_valid = true;
    			fault.error_code = 0;
    			fault.nested_page_fault = false;
    			fault.address = work->arch.token;
    			fault.async_page_fault = true;
    			kvm_inject_page_fault(vcpu, &fault);
    		}
    	}
    	vcpu->arch.apf.halted = false;
    	vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
    }
    
    bool kvm_arch_can_inject_async_page_present(struct kvm_vcpu *vcpu)
    {
    	if (!(vcpu->arch.apf.msr_val & KVM_ASYNC_PF_ENABLED))
    		return true;
    	else
    		return kvm_can_do_async_pf(vcpu);
    }
    
    void kvm_arch_start_assignment(struct kvm *kvm)
    {
    	atomic_inc(&kvm->arch.assigned_device_count);
    }
    EXPORT_SYMBOL_GPL(kvm_arch_start_assignment);
    
    void kvm_arch_end_assignment(struct kvm *kvm)
    {
    	atomic_dec(&kvm->arch.assigned_device_count);
    }
    EXPORT_SYMBOL_GPL(kvm_arch_end_assignment);
    
    bool kvm_arch_has_assigned_device(struct kvm *kvm)
    {
    	return atomic_read(&kvm->arch.assigned_device_count);
    }
    EXPORT_SYMBOL_GPL(kvm_arch_has_assigned_device);
    
    void kvm_arch_register_noncoherent_dma(struct kvm *kvm)
    {
    	atomic_inc(&kvm->arch.noncoherent_dma_count);
    }
    EXPORT_SYMBOL_GPL(kvm_arch_register_noncoherent_dma);
    
    void kvm_arch_unregister_noncoherent_dma(struct kvm *kvm)
    {
    	atomic_dec(&kvm->arch.noncoherent_dma_count);
    }
    EXPORT_SYMBOL_GPL(kvm_arch_unregister_noncoherent_dma);
    
    bool kvm_arch_has_noncoherent_dma(struct kvm *kvm)
    {
    	return atomic_read(&kvm->arch.noncoherent_dma_count);
    }
    EXPORT_SYMBOL_GPL(kvm_arch_has_noncoherent_dma);
    
    bool kvm_arch_has_irq_bypass(void)
    {
    	return kvm_x86_ops->update_pi_irte != NULL;
    }
    
    int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
    				      struct irq_bypass_producer *prod)
    {
    	struct kvm_kernel_irqfd *irqfd =
    		container_of(cons, struct kvm_kernel_irqfd, consumer);
    
    	irqfd->producer = prod;
    
    	return kvm_x86_ops->update_pi_irte(irqfd->kvm,
    					   prod->irq, irqfd->gsi, 1);
    }
    
    void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
    				      struct irq_bypass_producer *prod)
    {
    	int ret;
    	struct kvm_kernel_irqfd *irqfd =
    		container_of(cons, struct kvm_kernel_irqfd, consumer);
    
    	WARN_ON(irqfd->producer != prod);
    	irqfd->producer = NULL;
    
    	/*
    	 * When producer of consumer is unregistered, we change back to
    	 * remapped mode, so we can re-use the current implementation
    	 * when the irq is masked/disabled or the consumer side (KVM
    	 * int this case doesn't want to receive the interrupts.
    	*/
    	ret = kvm_x86_ops->update_pi_irte(irqfd->kvm, prod->irq, irqfd->gsi, 0);
    	if (ret)
    		printk(KERN_INFO "irq bypass consumer (token %p) unregistration"
    		       " fails: %d\n", irqfd->consumer.token, ret);
    }
    
    int kvm_arch_update_irqfd_routing(struct kvm *kvm, unsigned int host_irq,
    				   uint32_t guest_irq, bool set)
    {
    	if (!kvm_x86_ops->update_pi_irte)
    		return -EINVAL;
    
    	return kvm_x86_ops->update_pi_irte(kvm, host_irq, guest_irq, set);
    }
    
    bool kvm_vector_hashing_enabled(void)
    {
    	return vector_hashing;
    }
    EXPORT_SYMBOL_GPL(kvm_vector_hashing_enabled);
    
    EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_exit);
    EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_fast_mmio);
    EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_inj_virq);
    EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_page_fault);
    EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_msr);
    EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_cr);
    EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_vmrun);
    EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_vmexit);
    EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_vmexit_inject);
    EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_intr_vmexit);
    EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_invlpga);
    EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_skinit);
    EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_intercepts);
    EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_write_tsc_offset);
    EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_ple_window);
    EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_pml_full);
    EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_pi_irte_update);
    EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_unaccelerated_access);
    EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_incomplete_ipi);