diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index f345bcf38cfbdb0020f99c1d3ac5dad5e34838f1..b878fcd164ce1a2876453c1f1e0d0605e5dbbf11 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -601,6 +601,7 @@ struct kvm_vcpu_arch {
u64 ia32_xss;
u64 microcode_version;
u64 arch_capabilities;
+ u64 perf_capabilities;
/*
* Paging state of the vcpu
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index a9f1905896fb3c61db7bf12f821bdf72d61fb8e4..253b8e875ccd8f27aa8928ce9ea2b8826283b5e7 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -296,7 +296,7 @@ void kvm_set_cpu_caps(void)
F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
0 /* DS-CPL, VMX, SMX, EST */ |
0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
- F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ |
+ F(FMA) | F(CX16) | 0 /* xTPR Update */ | F(PDCM) |
F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) |
F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) |
diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index 8903475f751ef7a366b6f88d647070b82426c064..4bbd8b448d22dbc7312698104d8a0c0cbd7be808 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -18,6 +18,8 @@ extern int __read_mostly pt_mode;
#define PT_MODE_SYSTEM 0
#define PT_MODE_HOST_GUEST 1
+#define PMU_CAP_FW_WRITES (1ULL << 13)
+
struct nested_vmx_msrs {
/*
* We only store the "true" versions of the VMX capability MSRs. We
@@ -367,4 +369,13 @@ static inline bool vmx_pt_mode_is_host_guest(void)
return pt_mode == PT_MODE_HOST_GUEST;
}
+static inline u64 vmx_get_perf_capabilities(void)
+{
+ /*
+ * Since counters are virtualized, KVM would support full
+ * width counting unconditionally, even if the host lacks it.
+ */
+ return PMU_CAP_FW_WRITES;
+}
+
#endif /* __KVM_X86_VMX_CAPS_H */
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index e1a303fefc167104c0614879e8a5a440a23751d4..d33d890b605f82e17243e44bb2286877d4a92e88 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -18,6 +18,8 @@
#include "nested.h"
#include "pmu.h"
+#define MSR_PMC_FULL_WIDTH_BIT (MSR_IA32_PMC0 - MSR_IA32_PERFCTR0)
+
static struct kvm_event_hw_type_mapping intel_arch_events[] = {
/* Index must match CPUID 0x0A.EBX bit vector */
[0] = { 0x3c, 0x00, PERF_COUNT_HW_CPU_CYCLES },
@@ -150,6 +152,22 @@ static struct kvm_pmc *intel_rdpmc_ecx_to_pmc(struct kvm_vcpu *vcpu,
return &counters[array_index_nospec(idx, num_counters)];
}
+static inline bool fw_writes_is_enabled(struct kvm_vcpu *vcpu)
+{
+ if (!guest_cpuid_has(vcpu, X86_FEATURE_PDCM))
+ return false;
+
+ return vcpu->arch.perf_capabilities & PMU_CAP_FW_WRITES;
+}
+
+static inline struct kvm_pmc *get_fw_gp_pmc(struct kvm_pmu *pmu, u32 msr)
+{
+ if (!fw_writes_is_enabled(pmu_to_vcpu(pmu)))
+ return NULL;
+
+ return get_gp_pmc(pmu, msr, MSR_IA32_PMC0);
+}
+
static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
{
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
@@ -162,10 +180,13 @@ static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
ret = pmu->version > 1;
break;
+ case MSR_IA32_PERF_CAPABILITIES:
+ ret = guest_cpuid_has(vcpu, X86_FEATURE_PDCM);
+ break;
default:
ret = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0) ||
get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0) ||
- get_fixed_pmc(pmu, msr);
+ get_fixed_pmc(pmu, msr) || get_fw_gp_pmc(pmu, msr);
break;
}
@@ -203,8 +224,15 @@ static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
msr_info->data = pmu->global_ovf_ctrl;
return 0;
+ case MSR_IA32_PERF_CAPABILITIES:
+ if (!msr_info->host_initiated &&
+ !guest_cpuid_has(vcpu, X86_FEATURE_PDCM))
+ return 1;
+ msr_info->data = vcpu->arch.perf_capabilities;
+ return 0;
default:
- if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0))) {
+ if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) ||
+ (pmc = get_gp_pmc(pmu, msr, MSR_IA32_PMC0))) {
u64 val = pmc_read_counter(pmc);
msr_info->data =
val & pmu->counter_bitmask[KVM_PMC_GP];
@@ -261,9 +289,22 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
return 0;
}
break;
+ case MSR_IA32_PERF_CAPABILITIES:
+ if (!msr_info->host_initiated)
+ return 1;
+ if (guest_cpuid_has(vcpu, X86_FEATURE_PDCM) ?
+ (data & ~vmx_get_perf_capabilities()) : data)
+ return 1;
+ vcpu->arch.perf_capabilities = data;
+ return 0;
default:
- if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0))) {
- if (!msr_info->host_initiated)
+ if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) ||
+ (pmc = get_gp_pmc(pmu, msr, MSR_IA32_PMC0))) {
+ if ((msr & MSR_PMC_FULL_WIDTH_BIT) &&
+ (data & ~pmu->counter_bitmask[KVM_PMC_GP]))
+ return 1;
+ if (!msr_info->host_initiated &&
+ !(msr & MSR_PMC_FULL_WIDTH_BIT))
data = (s64)(s32)data;
pmc->counter += data - pmc_read_counter(pmc);
if (pmc->perf_event)
@@ -303,6 +344,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
pmu->counter_bitmask[KVM_PMC_FIXED] = 0;
pmu->version = 0;
pmu->reserved_bits = 0xffffffff00200000ull;
+ vcpu->arch.perf_capabilities = 0;
entry = kvm_find_cpuid_entry(vcpu, 0xa, 0);
if (!entry)
@@ -315,6 +357,8 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
return;
perf_get_x86_pmu_capability(&x86_pmu);
+ if (guest_cpuid_has(vcpu, X86_FEATURE_PDCM))
+ vcpu->arch.perf_capabilities = vmx_get_perf_capabilities();
pmu->nr_arch_gp_counters = min_t(int, eax.split.num_counters,
x86_pmu.num_counters_gp);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 5a43af0061efa18d951d745b12370f75746d9011..170cc76a581f4a0ef186bff2e42a078ab7ca2b50 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1788,6 +1788,9 @@ static int vmx_get_msr_feature(struct kvm_msr_entry *msr)
if (!nested)
return 1;
return vmx_get_vmx_msr(&vmcs_config.nested, msr->index, &msr->data);
+ case MSR_IA32_PERF_CAPABILITIES:
+ msr->data = vmx_get_perf_capabilities();
+ return 0;
default:
return 1;
}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 7e34ff7846954057ce0c9289911ef97b0563dcdc..ca8a57312291f73c24c255d6a12fde0ae7627991 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1253,6 +1253,7 @@ static const u32 emulated_msrs_all[] = {
MSR_IA32_TSC_ADJUST,
MSR_IA32_TSCDEADLINE,
MSR_IA32_ARCH_CAPABILITIES,
+ MSR_IA32_PERF_CAPABILITIES,
MSR_IA32_MISC_ENABLE,
MSR_IA32_MCG_STATUS,
MSR_IA32_MCG_CTL,
@@ -1319,6 +1320,7 @@ static const u32 msr_based_features_all[] = {
MSR_F10H_DECFG,
MSR_IA32_UCODE_REV,
MSR_IA32_ARCH_CAPABILITIES,
+ MSR_IA32_PERF_CAPABILITIES,
};
static u32 msr_based_features[ARRAY_SIZE(msr_based_features_all)];