This patch adds support for AMD Core Performance counters in the guest.
The base event select and counter MSRs are changed. In addition, with
the core extension, there are 2 extra counters available for performance
measurements for a total of 6.
With the new MSRs, the logic to map them to the gp_counters[] is changed.
New functions are introduced to get the right base MSRs and to check the
validity of the get/set MSRs.
If the guest has vcpus of either family 16h or a generation < 15h, it
falls back to using K7 MSRs and the number of counters the guest can
access is set to 4.
Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@xxxxxxx>
---
arch/x86/kvm/pmu_amd.c | 133 +++++++++++++++++++++++++++++++++++++++++++------
arch/x86/kvm/x86.c | 1 +
2 files changed, 120 insertions(+), 14 deletions(-)
diff --git a/arch/x86/kvm/pmu_amd.c b/arch/x86/kvm/pmu_amd.c
index cd94443..2c694446 100644
--- a/arch/x86/kvm/pmu_amd.c
+++ b/arch/x86/kvm/pmu_amd.c
@@ -19,6 +19,11 @@
#include "lapic.h"
#include "pmu.h"
+enum pmu_type {
+ PMU_TYPE_COUNTER = 0,
+ PMU_TYPE_EVNTSEL,
+};
+
/* duplicated from amd_perfmon_event_map, K7 and above should work. */
static struct kvm_event_hw_type_mapping amd_event_mapping[] = {
[0] = { 0x76, 0x00, PERF_COUNT_HW_CPU_CYCLES },
@@ -31,6 +36,86 @@ static struct kvm_event_hw_type_mapping amd_event_mapping[] = {
[7] = { 0xd1, 0x00, PERF_COUNT_HW_STALLED_CYCLES_BACKEND },
};
+static unsigned int get_msr_base(struct kvm_pmu *pmu, enum pmu_type type)
+{
+ struct kvm_vcpu *vcpu = pmu_to_vcpu(pmu);
+ int family;
+ bool has_perf_ext;
+
+ family = guest_cpuid_family(vcpu);
+ has_perf_ext = guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE);
+
+ switch (family) {
+ case 0x15:
+ case 0x17:
+ if (has_perf_ext) {
+ if (type == PMU_TYPE_COUNTER)
+ return MSR_F15H_PERF_CTR;
+ else
+ return MSR_F15H_PERF_CTL;
+ break;
+ }
+ /*
+ * Fall-through because the K7 MSRs are
+ * backwards compatible
+ */
+ default:
+ if (type == PMU_TYPE_COUNTER)
+ return MSR_K7_PERFCTR0;
+ else
+ return MSR_K7_EVNTSEL0;
+ }
+}
+
+static inline struct kvm_pmc *get_gp_pmc_amd(struct kvm_pmu *pmu, u32 msr,
+ enum pmu_type type)
+{
+ unsigned int base = get_msr_base(pmu, type);
+
+ if (base == MSR_F15H_PERF_CTL) {
+ switch (msr) {
+ case MSR_F15H_PERF_CTL0:
+ case MSR_F15H_PERF_CTL1:
+ case MSR_F15H_PERF_CTL2:
+ case MSR_F15H_PERF_CTL3:
+ case MSR_F15H_PERF_CTL4:
+ case MSR_F15H_PERF_CTL5:
+ /*
+ * AMD Perf Extension MSRs are not continuous.
+ *
+ * E.g. MSR_F15H_PERF_CTR0 -> 0xc0010201
+ * MSR_F15H_PERF_CTR1 -> 0xc0010203
+ *
+ * These are mapped to work with gp_counters[].
+ * The index into the array is calculated by
+ * dividing the difference between the requested
+ * msr and the msr base by 2.
+ *
+ * E.g. MSR_F15H_PERF_CTR1 uses
+ * ->gp_counters[(0xc0010203-0xc0010201)/2]
+ * ->gp_counters[1]
+ */
+ return &pmu->gp_counters[(msr - base) >> 1];
+ default:
+ return NULL;
+ }
+ } else if (base == MSR_F15H_PERF_CTR) {
+ switch (msr) {
+ case MSR_F15H_PERF_CTR0:
+ case MSR_F15H_PERF_CTR1:
+ case MSR_F15H_PERF_CTR2:
+ case MSR_F15H_PERF_CTR3:
+ case MSR_F15H_PERF_CTR4:
+ case MSR_F15H_PERF_CTR5:
+ return &pmu->gp_counters[(msr - base) >> 1];
+ default:
+ return NULL;
+ }
+ } else {
+ return get_gp_pmc(pmu, msr, base);
+ }
+}
+
static unsigned amd_find_arch_event(struct kvm_pmu *pmu,
u8 event_select,
u8 unit_mask)
@@ -64,7 +149,20 @@ static bool amd_pmc_is_enabled(struct kvm_pmc *pmc)
static struct kvm_pmc *amd_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx)
{
- return get_gp_pmc(pmu, MSR_K7_EVNTSEL0 + pmc_idx, MSR_K7_EVNTSEL0);
+ unsigned int base = get_msr_base(pmu, PMU_TYPE_COUNTER);
+ unsigned int family;
+
+ family = guest_cpuid_family(pmu_to_vcpu(pmu));
+
+ if (family == 0x15 || family == 0x17) {
+ /*
+ * The idx is contiguous. The MSRs are not. The counter MSRs
+ * are interleaved with the event select MSRs.
+ */
+ pmc_idx *= 2;
+ }
+
+ return get_gp_pmc_amd(pmu, base + pmc_idx, PMU_TYPE_COUNTER);
}
/* returns 0 if idx's corresponding MSR exists; otherwise returns 1. */
@@ -96,8 +194,8 @@ static bool amd_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
int ret = false;
- ret = get_gp_pmc(pmu, msr, MSR_K7_PERFCTR0) ||
- get_gp_pmc(pmu, msr, MSR_K7_EVNTSEL0);
+ ret = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER) ||
+ get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL);
return ret;
}
@@ -107,14 +205,14 @@ static int amd_pmu_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *data)
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
struct kvm_pmc *pmc;
- /* MSR_K7_PERFCTRn */
- pmc = get_gp_pmc(pmu, msr, MSR_K7_PERFCTR0);
+ /* MSR_PERFCTRn */
+ pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER);
if (pmc) {
*data = pmc_read_counter(pmc);
return 0;
}
- /* MSR_K7_EVNTSELn */
- pmc = get_gp_pmc(pmu, msr, MSR_K7_EVNTSEL0);
+ /* MSR_EVNTSELn */
+ pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL);
if (pmc) {
*data = pmc->eventsel;
return 0;
@@ -130,14 +228,14 @@ static int amd_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
u32 msr = msr_info->index;
u64 data = msr_info->data;
- /* MSR_K7_PERFCTRn */
- pmc = get_gp_pmc(pmu, msr, MSR_K7_PERFCTR0);
+ /* MSR_PERFCTRn */
+ pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER);
if (pmc) {
pmc->counter += data - pmc_read_counter(pmc);
return 0;
}
- /* MSR_K7_EVNTSELn */
- pmc = get_gp_pmc(pmu, msr, MSR_K7_EVNTSEL0);
+ /* MSR_EVNTSELn */
+ pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL);
if (pmc) {
if (data == pmc->eventsel)
return 0;
@@ -153,8 +251,15 @@ static int amd_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
static void amd_pmu_refresh(struct kvm_vcpu *vcpu)
{
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
+ int family, nr_counters;
+
+ family = guest_cpuid_family(vcpu);
+ if (family == 0x15 || family == 0x17)
+ nr_counters = AMD64_NUM_COUNTERS_CORE;
+ else
+ nr_counters = AMD64_NUM_COUNTERS;
- pmu->nr_arch_gp_counters = AMD64_NUM_COUNTERS;
+ pmu->nr_arch_gp_counters = nr_counters;
pmu->counter_bitmask[KVM_PMC_GP] = ((u64)1 << 48) - 1;
pmu->reserved_bits = 0xffffffff00200000ull;
/* not applicable to AMD; but clean them to prevent any fall out */
@@ -169,7 +274,7 @@ static void amd_pmu_init(struct kvm_vcpu *vcpu)
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
int i;
- for (i = 0; i < AMD64_NUM_COUNTERS ; i++) {
+ for (i = 0; i < AMD64_NUM_COUNTERS_CORE ; i++) {
pmu->gp_counters[i].type = KVM_PMC_GP;
pmu->gp_counters[i].vcpu = vcpu;
pmu->gp_counters[i].idx = i;
@@ -181,7 +286,7 @@ static void amd_pmu_reset(struct kvm_vcpu *vcpu)
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
int i;
- for (i = 0; i < AMD64_NUM_COUNTERS; i++) {
+ for (i = 0; i < AMD64_NUM_COUNTERS_CORE; i++) {
struct kvm_pmc *pmc = &pmu->gp_counters[i];
pmc_stop_counter(pmc);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 03869eb..5a6ad6f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2433,6 +2433,7 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
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:
--
2.7.4
