diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h
index a1057961ac46625bc3ba8b4667a264876599f7e3..475e34f537938dd69ae6b5796cb1a18950681356 100644
--- a/arch/x86/include/asm/mem_encrypt.h
+++ b/arch/x86/include/asm/mem_encrypt.h
@@ -15,14 +15,22 @@
#ifndef __ASSEMBLY__
+#include <linux/init.h>
+
#ifdef CONFIG_AMD_MEM_ENCRYPT
extern unsigned long sme_me_mask;
+void __init sme_encrypt_kernel(void);
+void __init sme_enable(void);
+
#else /* !CONFIG_AMD_MEM_ENCRYPT */
#define sme_me_mask 0UL
+static inline void __init sme_encrypt_kernel(void) { }
+static inline void __init sme_enable(void) { }
+
#endif /* CONFIG_AMD_MEM_ENCRYPT */
#endif /* __ASSEMBLY__ */
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 46c3c73e7f43f5fbb56fe0028d8aafb64a3f8a9e..1f0ddcc9675cb4910ed5c54ad35b9fdb2dc05966 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -14,6 +14,7 @@
#include <linux/start_kernel.h>
#include <linux/io.h>
#include <linux/memblock.h>
+#include <linux/mem_encrypt.h>
#include <asm/processor.h>
#include <asm/proto.h>
@@ -45,9 +46,10 @@ static void __head *fixup_pointer(void *ptr, unsigned long physaddr)
return ptr - (void *)_text + (void *)physaddr;
}
-void __head __startup_64(unsigned long physaddr)
+unsigned long __head __startup_64(unsigned long physaddr)
{
unsigned long load_delta, *p;
+ unsigned long pgtable_flags;
pgdval_t *pgd;
p4dval_t *p4d;
pudval_t *pud;
@@ -68,6 +70,12 @@ void __head __startup_64(unsigned long physaddr)
if (load_delta & ~PMD_PAGE_MASK)
for (;;);
+ /* Activate Secure Memory Encryption (SME) if supported and enabled */
+ sme_enable();
+
+ /* Include the SME encryption mask in the fixup value */
+ load_delta += sme_get_me_mask();
+
/* Fixup the physical addresses in the page table */
pgd = fixup_pointer(&early_top_pgt, physaddr);
@@ -94,28 +102,30 @@ void __head __startup_64(unsigned long physaddr)
pud = fixup_pointer(early_dynamic_pgts[next_early_pgt++], physaddr);
pmd = fixup_pointer(early_dynamic_pgts[next_early_pgt++], physaddr);
+ pgtable_flags = _KERNPG_TABLE + sme_get_me_mask();
if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
p4d = fixup_pointer(early_dynamic_pgts[next_early_pgt++], physaddr);
i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD;
- pgd[i + 0] = (pgdval_t)p4d + _KERNPG_TABLE;
- pgd[i + 1] = (pgdval_t)p4d + _KERNPG_TABLE;
+ pgd[i + 0] = (pgdval_t)p4d + pgtable_flags;
+ pgd[i + 1] = (pgdval_t)p4d + pgtable_flags;
i = (physaddr >> P4D_SHIFT) % PTRS_PER_P4D;
- p4d[i + 0] = (pgdval_t)pud + _KERNPG_TABLE;
- p4d[i + 1] = (pgdval_t)pud + _KERNPG_TABLE;
+ p4d[i + 0] = (pgdval_t)pud + pgtable_flags;
+ p4d[i + 1] = (pgdval_t)pud + pgtable_flags;
} else {
i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD;
- pgd[i + 0] = (pgdval_t)pud + _KERNPG_TABLE;
- pgd[i + 1] = (pgdval_t)pud + _KERNPG_TABLE;
+ pgd[i + 0] = (pgdval_t)pud + pgtable_flags;
+ pgd[i + 1] = (pgdval_t)pud + pgtable_flags;
}
i = (physaddr >> PUD_SHIFT) % PTRS_PER_PUD;
- pud[i + 0] = (pudval_t)pmd + _KERNPG_TABLE;
- pud[i + 1] = (pudval_t)pmd + _KERNPG_TABLE;
+ pud[i + 0] = (pudval_t)pmd + pgtable_flags;
+ pud[i + 1] = (pudval_t)pmd + pgtable_flags;
pmd_entry = __PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL;
+ pmd_entry += sme_get_me_mask();
pmd_entry += physaddr;
for (i = 0; i < DIV_ROUND_UP(_end - _text, PMD_SIZE); i++) {
@@ -136,9 +146,30 @@ void __head __startup_64(unsigned long physaddr)
pmd[i] += load_delta;
}
- /* Fixup phys_base */
+ /*
+ * Fixup phys_base - remove the memory encryption mask to obtain
+ * the true physical address.
+ */
p = fixup_pointer(&phys_base, physaddr);
- *p += load_delta;
+ *p += load_delta - sme_get_me_mask();
+
+ /* Encrypt the kernel (if SME is active) */
+ sme_encrypt_kernel();
+
+ /*
+ * Return the SME encryption mask (if SME is active) to be used as a
+ * modifier for the initial pgdir entry programmed into CR3.
+ */
+ return sme_get_me_mask();
+}
+
+unsigned long __startup_secondary_64(void)
+{
+ /*
+ * Return the SME encryption mask (if SME is active) to be used as a
+ * modifier for the initial pgdir entry programmed into CR3.
+ */
+ return sme_get_me_mask();
}
/* Wipe all early page tables except for the kernel symbol map */
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 6225550883dfe1e98bcf35ac5ed870e334b34399..ec5d5e90c8f199cb78282e42a012c451e5494abc 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -73,12 +73,19 @@ startup_64:
/* Sanitize CPU configuration */
call verify_cpu
+ /*
+ * Perform pagetable fixups. Additionally, if SME is active, encrypt
+ * the kernel and retrieve the modifier (SME encryption mask if SME
+ * is active) to be added to the initial pgdir entry that will be
+ * programmed into CR3.
+ */
leaq _text(%rip), %rdi
pushq %rsi
call __startup_64
popq %rsi
- movq $(early_top_pgt - __START_KERNEL_map), %rax
+ /* Form the CR3 value being sure to include the CR3 modifier */
+ addq $(early_top_pgt - __START_KERNEL_map), %rax
jmp 1f
ENTRY(secondary_startup_64)
/*
@@ -98,7 +105,16 @@ ENTRY(secondary_startup_64)
/* Sanitize CPU configuration */
call verify_cpu
- movq $(init_top_pgt - __START_KERNEL_map), %rax
+ /*
+ * Retrieve the modifier (SME encryption mask if SME is active) to be
+ * added to the initial pgdir entry that will be programmed into CR3.
+ */
+ pushq %rsi
+ call __startup_secondary_64
+ popq %rsi
+
+ /* Form the CR3 value being sure to include the CR3 modifier */
+ addq $(init_top_pgt - __START_KERNEL_map), %rax
1:
/* Enable PAE mode, PGE and LA57 */
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index b99d469c73e766e37dfd66239a2f109bb7fa39f2..3ac6f99b095c040dfd68d4368a7fd89fdb3ad683 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -11,6 +11,7 @@
*/
#include <linux/linkage.h>
+#include <linux/init.h>
/*
* Since SME related variables are set early in the boot process they must
@@ -19,3 +20,11 @@
*/
unsigned long sme_me_mask __section(.data) = 0;
EXPORT_SYMBOL_GPL(sme_me_mask);
+
+void __init sme_encrypt_kernel(void)
+{
+}
+
+void __init sme_enable(void)
+{
+}
diff --git a/include/linux/mem_encrypt.h b/include/linux/mem_encrypt.h
index 59769f7287e4d3c18e25360eaa3de44ec62d83de..570f4fcff13f174c9c47590fb4e4d40adaaaed96 100644
--- a/include/linux/mem_encrypt.h
+++ b/include/linux/mem_encrypt.h
@@ -30,6 +30,11 @@ static inline bool sme_active(void)
return !!sme_me_mask;
}
+static inline unsigned long sme_get_me_mask(void)
+{
+ return sme_me_mask;
+}
+
#endif /* __ASSEMBLY__ */
#endif /* __MEM_ENCRYPT_H__ */