diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index 48a15d4b820e04df68589aa265ac0a8d78349782..16c769a7f979e387f58d65e094f9531213ad1f8b 100644
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h
@@ -11,6 +11,7 @@
#include <asm/perf_event.h>
#define ARMV8_PMU_CYCLE_IDX (ARMV8_PMU_MAX_COUNTERS - 1)
+#define ARMV8_PMU_MAX_COUNTER_PAIRS ((ARMV8_PMU_MAX_COUNTERS + 1) >> 1)
#ifdef CONFIG_KVM_ARM_PMU
@@ -22,6 +23,7 @@ struct kvm_pmc {
struct kvm_pmu {
int irq_num;
struct kvm_pmc pmc[ARMV8_PMU_MAX_COUNTERS];
+ DECLARE_BITMAP(chained, ARMV8_PMU_MAX_COUNTER_PAIRS);
bool ready;
bool created;
bool irq_level;
diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
index 24c6cf869a16464ec2a38c64af056366b674e3ef..3dd8238ed2462eeeb04e5c7cfa2735e3782d02bd 100644
--- a/virt/kvm/arm/pmu.c
+++ b/virt/kvm/arm/pmu.c
@@ -15,6 +15,8 @@
static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx);
+#define PERF_ATTR_CFG1_KVM_PMU_CHAINED 0x1
+
/**
* kvm_pmu_idx_is_64bit - determine if select_idx is a 64bit counter
* @vcpu: The vcpu pointer
@@ -26,29 +28,126 @@ static bool kvm_pmu_idx_is_64bit(struct kvm_vcpu *vcpu, u64 select_idx)
__vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_LC);
}
+static struct kvm_vcpu *kvm_pmc_to_vcpu(struct kvm_pmc *pmc)
+{
+ struct kvm_pmu *pmu;
+ struct kvm_vcpu_arch *vcpu_arch;
+
+ pmc -= pmc->idx;
+ pmu = container_of(pmc, struct kvm_pmu, pmc[0]);
+ vcpu_arch = container_of(pmu, struct kvm_vcpu_arch, pmu);
+ return container_of(vcpu_arch, struct kvm_vcpu, arch);
+}
+
/**
- * kvm_pmu_get_counter_value - get PMU counter value
+ * kvm_pmu_pmc_is_chained - determine if the pmc is chained
+ * @pmc: The PMU counter pointer
+ */
+static bool kvm_pmu_pmc_is_chained(struct kvm_pmc *pmc)
+{
+ struct kvm_vcpu *vcpu = kvm_pmc_to_vcpu(pmc);
+
+ return test_bit(pmc->idx >> 1, vcpu->arch.pmu.chained);
+}
+
+/**
+ * kvm_pmu_idx_is_high_counter - determine if select_idx is a high/low counter
+ * @select_idx: The counter index
+ */
+static bool kvm_pmu_idx_is_high_counter(u64 select_idx)
+{
+ return select_idx & 0x1;
+}
+
+/**
+ * kvm_pmu_get_canonical_pmc - obtain the canonical pmc
+ * @pmc: The PMU counter pointer
+ *
+ * When a pair of PMCs are chained together we use the low counter (canonical)
+ * to hold the underlying perf event.
+ */
+static struct kvm_pmc *kvm_pmu_get_canonical_pmc(struct kvm_pmc *pmc)
+{
+ if (kvm_pmu_pmc_is_chained(pmc) &&
+ kvm_pmu_idx_is_high_counter(pmc->idx))
+ return pmc - 1;
+
+ return pmc;
+}
+
+/**
+ * kvm_pmu_idx_has_chain_evtype - determine if the event type is chain
* @vcpu: The vcpu pointer
* @select_idx: The counter index
*/
-u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx)
+static bool kvm_pmu_idx_has_chain_evtype(struct kvm_vcpu *vcpu, u64 select_idx)
{
- u64 counter, reg, enabled, running;
- struct kvm_pmu *pmu = &vcpu->arch.pmu;
- struct kvm_pmc *pmc = &pmu->pmc[select_idx];
+ u64 eventsel, reg;
- reg = (select_idx == ARMV8_PMU_CYCLE_IDX)
- ? PMCCNTR_EL0 : PMEVCNTR0_EL0 + select_idx;
- counter = __vcpu_sys_reg(vcpu, reg);
+ select_idx |= 0x1;
+
+ if (select_idx == ARMV8_PMU_CYCLE_IDX)
+ return false;
+
+ reg = PMEVTYPER0_EL0 + select_idx;
+ eventsel = __vcpu_sys_reg(vcpu, reg) & ARMV8_PMU_EVTYPE_EVENT;
+
+ return eventsel == ARMV8_PMUV3_PERFCTR_CHAIN;
+}
+
+/**
+ * kvm_pmu_get_pair_counter_value - get PMU counter value
+ * @vcpu: The vcpu pointer
+ * @pmc: The PMU counter pointer
+ */
+static u64 kvm_pmu_get_pair_counter_value(struct kvm_vcpu *vcpu,
+ struct kvm_pmc *pmc)
+{
+ u64 counter, counter_high, reg, enabled, running;
- /* The real counter value is equal to the value of counter register plus
+ if (kvm_pmu_pmc_is_chained(pmc)) {
+ pmc = kvm_pmu_get_canonical_pmc(pmc);
+ reg = PMEVCNTR0_EL0 + pmc->idx;
+
+ counter = __vcpu_sys_reg(vcpu, reg);
+ counter_high = __vcpu_sys_reg(vcpu, reg + 1);
+
+ counter = lower_32_bits(counter) | (counter_high << 32);
+ } else {
+ reg = (pmc->idx == ARMV8_PMU_CYCLE_IDX)
+ ? PMCCNTR_EL0 : PMEVCNTR0_EL0 + pmc->idx;
+ counter = __vcpu_sys_reg(vcpu, reg);
+ }
+
+ /*
+ * The real counter value is equal to the value of counter register plus
* the value perf event counts.
*/
if (pmc->perf_event)
counter += perf_event_read_value(pmc->perf_event, &enabled,
&running);
- if (!kvm_pmu_idx_is_64bit(vcpu, select_idx))
+ return counter;
+}
+
+/**
+ * kvm_pmu_get_counter_value - get PMU counter value
+ * @vcpu: The vcpu pointer
+ * @select_idx: The counter index
+ */
+u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx)
+{
+ u64 counter;
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+ struct kvm_pmc *pmc = &pmu->pmc[select_idx];
+
+ counter = kvm_pmu_get_pair_counter_value(vcpu, pmc);
+
+ if (kvm_pmu_pmc_is_chained(pmc) &&
+ kvm_pmu_idx_is_high_counter(select_idx))
+ counter = upper_32_bits(counter);
+
+ else if (!kvm_pmu_idx_is_64bit(vcpu, select_idx))
counter = lower_32_bits(counter);
return counter;
@@ -78,6 +177,7 @@ void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val)
*/
static void kvm_pmu_release_perf_event(struct kvm_pmc *pmc)
{
+ pmc = kvm_pmu_get_canonical_pmc(pmc);
if (pmc->perf_event) {
perf_event_disable(pmc->perf_event);
perf_event_release_kernel(pmc->perf_event);
@@ -95,13 +195,23 @@ static void kvm_pmu_stop_counter(struct kvm_vcpu *vcpu, struct kvm_pmc *pmc)
{
u64 counter, reg;
- if (pmc->perf_event) {
- counter = kvm_pmu_get_counter_value(vcpu, pmc->idx);
+ pmc = kvm_pmu_get_canonical_pmc(pmc);
+ if (!pmc->perf_event)
+ return;
+
+ counter = kvm_pmu_get_pair_counter_value(vcpu, pmc);
+
+ if (kvm_pmu_pmc_is_chained(pmc)) {
+ reg = PMEVCNTR0_EL0 + pmc->idx;
+ __vcpu_sys_reg(vcpu, reg) = lower_32_bits(counter);
+ __vcpu_sys_reg(vcpu, reg + 1) = upper_32_bits(counter);
+ } else {
reg = (pmc->idx == ARMV8_PMU_CYCLE_IDX)
? PMCCNTR_EL0 : PMEVCNTR0_EL0 + pmc->idx;
- __vcpu_sys_reg(vcpu, reg) = counter;
- kvm_pmu_release_perf_event(pmc);
+ __vcpu_sys_reg(vcpu, reg) = lower_32_bits(counter);
}
+
+ kvm_pmu_release_perf_event(pmc);
}
/**
@@ -118,6 +228,8 @@ void kvm_pmu_vcpu_reset(struct kvm_vcpu *vcpu)
kvm_pmu_stop_counter(vcpu, &pmu->pmc[i]);
pmu->pmc[i].idx = i;
}
+
+ bitmap_zero(vcpu->arch.pmu.chained, ARMV8_PMU_MAX_COUNTER_PAIRS);
}
/**
@@ -166,6 +278,18 @@ void kvm_pmu_enable_counter_mask(struct kvm_vcpu *vcpu, u64 val)
continue;
pmc = &pmu->pmc[i];
+
+ /*
+ * For high counters of chained events we must recreate the
+ * perf event with the long (64bit) attribute set.
+ */
+ if (kvm_pmu_pmc_is_chained(pmc) &&
+ kvm_pmu_idx_is_high_counter(i)) {
+ kvm_pmu_create_perf_event(vcpu, i);
+ continue;
+ }
+
+ /* At this point, pmc must be the canonical */
if (pmc->perf_event) {
perf_event_enable(pmc->perf_event);
if (pmc->perf_event->state != PERF_EVENT_STATE_ACTIVE)
@@ -195,6 +319,18 @@ void kvm_pmu_disable_counter_mask(struct kvm_vcpu *vcpu, u64 val)
continue;
pmc = &pmu->pmc[i];
+
+ /*
+ * For high counters of chained events we must recreate the
+ * perf event with the long (64bit) attribute unset.
+ */
+ if (kvm_pmu_pmc_is_chained(pmc) &&
+ kvm_pmu_idx_is_high_counter(i)) {
+ kvm_pmu_create_perf_event(vcpu, i);
+ continue;
+ }
+
+ /* At this point, pmc must be the canonical */
if (pmc->perf_event)
perf_event_disable(pmc->perf_event);
}
@@ -284,17 +420,6 @@ void kvm_pmu_sync_hwstate(struct kvm_vcpu *vcpu)
kvm_pmu_update_state(vcpu);
}
-static inline struct kvm_vcpu *kvm_pmc_to_vcpu(struct kvm_pmc *pmc)
-{
- struct kvm_pmu *pmu;
- struct kvm_vcpu_arch *vcpu_arch;
-
- pmc -= pmc->idx;
- pmu = container_of(pmc, struct kvm_pmu, pmc[0]);
- vcpu_arch = container_of(pmu, struct kvm_vcpu_arch, pmu);
- return container_of(vcpu_arch, struct kvm_vcpu, arch);
-}
-
/**
* When the perf event overflows, set the overflow status and inform the vcpu.
*/
@@ -385,13 +510,20 @@ static bool kvm_pmu_counter_is_enabled(struct kvm_vcpu *vcpu, u64 select_idx)
static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx)
{
struct kvm_pmu *pmu = &vcpu->arch.pmu;
- struct kvm_pmc *pmc = &pmu->pmc[select_idx];
+ struct kvm_pmc *pmc;
struct perf_event *event;
struct perf_event_attr attr;
u64 eventsel, counter, reg, data;
- reg = (select_idx == ARMV8_PMU_CYCLE_IDX)
- ? PMCCFILTR_EL0 : PMEVTYPER0_EL0 + select_idx;
+ /*
+ * For chained counters the event type and filtering attributes are
+ * obtained from the low/even counter. We also use this counter to
+ * determine if the event is enabled/disabled.
+ */
+ pmc = kvm_pmu_get_canonical_pmc(&pmu->pmc[select_idx]);
+
+ reg = (pmc->idx == ARMV8_PMU_CYCLE_IDX)
+ ? PMCCFILTR_EL0 : PMEVTYPER0_EL0 + pmc->idx;
data = __vcpu_sys_reg(vcpu, reg);
kvm_pmu_stop_counter(vcpu, pmc);
@@ -399,30 +531,47 @@ static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx)
/* Software increment event does't need to be backed by a perf event */
if (eventsel == ARMV8_PMUV3_PERFCTR_SW_INCR &&
- select_idx != ARMV8_PMU_CYCLE_IDX)
+ pmc->idx != ARMV8_PMU_CYCLE_IDX)
return;
memset(&attr, 0, sizeof(struct perf_event_attr));
attr.type = PERF_TYPE_RAW;
attr.size = sizeof(attr);
attr.pinned = 1;
- attr.disabled = !kvm_pmu_counter_is_enabled(vcpu, select_idx);
+ attr.disabled = !kvm_pmu_counter_is_enabled(vcpu, pmc->idx);
attr.exclude_user = data & ARMV8_PMU_EXCLUDE_EL0 ? 1 : 0;
attr.exclude_kernel = data & ARMV8_PMU_EXCLUDE_EL1 ? 1 : 0;
attr.exclude_hv = 1; /* Don't count EL2 events */
attr.exclude_host = 1; /* Don't count host events */
- attr.config = (select_idx == ARMV8_PMU_CYCLE_IDX) ?
+ attr.config = (pmc->idx == ARMV8_PMU_CYCLE_IDX) ?
ARMV8_PMUV3_PERFCTR_CPU_CYCLES : eventsel;
- counter = kvm_pmu_get_counter_value(vcpu, select_idx);
- /* The initial sample period (overflow count) of an event. */
- if (kvm_pmu_idx_is_64bit(vcpu, pmc->idx))
+ counter = kvm_pmu_get_pair_counter_value(vcpu, pmc);
+
+ if (kvm_pmu_idx_has_chain_evtype(vcpu, pmc->idx)) {
+ /**
+ * The initial sample period (overflow count) of an event. For
+ * chained counters we only support overflow interrupts on the
+ * high counter.
+ */
attr.sample_period = (-counter) & GENMASK(63, 0);
- else
- attr.sample_period = (-counter) & GENMASK(31, 0);
+ event = perf_event_create_kernel_counter(&attr, -1, current,
+ kvm_pmu_perf_overflow,
+ pmc + 1);
+
+ if (kvm_pmu_counter_is_enabled(vcpu, pmc->idx + 1))
+ attr.config1 |= PERF_ATTR_CFG1_KVM_PMU_CHAINED;
+ } else {
+ /* The initial sample period (overflow count) of an event. */
+ if (kvm_pmu_idx_is_64bit(vcpu, pmc->idx))
+ attr.sample_period = (-counter) & GENMASK(63, 0);
+ else
+ attr.sample_period = (-counter) & GENMASK(31, 0);
- event = perf_event_create_kernel_counter(&attr, -1, current,
+ event = perf_event_create_kernel_counter(&attr, -1, current,
kvm_pmu_perf_overflow, pmc);
+ }
+
if (IS_ERR(event)) {
pr_err_once("kvm: pmu event creation failed %ld\n",
PTR_ERR(event));
@@ -432,6 +581,33 @@ static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx)
pmc->perf_event = event;
}
+/**
+ * kvm_pmu_update_pmc_chained - update chained bitmap
+ * @vcpu: The vcpu pointer
+ * @select_idx: The number of selected counter
+ *
+ * Update the chained bitmap based on the event type written in the
+ * typer register.
+ */
+static void kvm_pmu_update_pmc_chained(struct kvm_vcpu *vcpu, u64 select_idx)
+{
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+ struct kvm_pmc *pmc = &pmu->pmc[select_idx];
+
+ if (kvm_pmu_idx_has_chain_evtype(vcpu, pmc->idx)) {
+ /*
+ * During promotion from !chained to chained we must ensure
+ * the adjacent counter is stopped and its event destroyed
+ */
+ if (!kvm_pmu_pmc_is_chained(pmc))
+ kvm_pmu_stop_counter(vcpu, pmc);
+
+ set_bit(pmc->idx >> 1, vcpu->arch.pmu.chained);
+ } else {
+ clear_bit(pmc->idx >> 1, vcpu->arch.pmu.chained);
+ }
+}
+
/**
* kvm_pmu_set_counter_event_type - set selected counter to monitor some event
* @vcpu: The vcpu pointer
@@ -451,6 +627,8 @@ void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data,
? PMCCFILTR_EL0 : PMEVTYPER0_EL0 + select_idx;
__vcpu_sys_reg(vcpu, reg) = event_type;
+
+ kvm_pmu_update_pmc_chained(vcpu, select_idx);
kvm_pmu_create_perf_event(vcpu, select_idx);
}