KVM: x86: move MSR_IA32_PERF_CAPABILITIES emulation to common x86 code

state_test/smm_test selftests are failing on AMD with:
"Unexpected result from KVM_GET_MSRS, r: 51 (failed MSR was 0x345)"

MSR_IA32_PERF_CAPABILITIES is an emulated MSR on Intel but it is not
known to AMD code, we can move the emulation to common x86 code. For
AMD, we basically just allow the host to read and write zero to the MSR.

Fixes: 27461da3 ("KVM: x86/pmu: Support full width counting")
Suggested-by: Jim Mattson <jmattson@google.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20200710152559.1645827-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/svm/svm.c

@@ -2358,6 +2358,8 @@ static int svm_get_msr_feature(struct kvm_msr_entry *msr)
 		if (boot_cpu_has(X86_FEATURE_LFENCE_RDTSC))
 			msr->data |= MSR_F10H_DECFG_LFENCE_SERIALIZE;
 		break;
+	case MSR_IA32_PERF_CAPABILITIES:
+		return 0;
 	default:
 		return KVM_MSR_RET_INVALID;
 	}

arch/x86/kvm/vmx/pmu_intel.c

@@ -180,9 +180,6 @@ 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 = 1;
-		break;
 	default:
 		ret = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0) ||
 			get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0) ||
@@ -224,12 +221,6 @@ 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)) ||
 		    (pmc = get_gp_pmc(pmu, msr, MSR_IA32_PMC0))) {
@@ -289,14 +280,6 @@ 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)) ||
 		    (pmc = get_gp_pmc(pmu, msr, MSR_IA32_PMC0))) {

arch/x86/kvm/x86.c

@@ -2857,6 +2857,20 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 			return 1;
 		vcpu->arch.arch_capabilities = data;
 		break;
+	case MSR_IA32_PERF_CAPABILITIES: {
+		struct kvm_msr_entry msr_ent = {.index = msr, .data = 0};
+
+		if (!msr_info->host_initiated)
+			return 1;
+		if (guest_cpuid_has(vcpu, X86_FEATURE_PDCM) && kvm_get_msr_feature(&msr_ent))
+			return 1;
+		if (data & ~msr_ent.data)
+			return 1;
+
+		vcpu->arch.perf_capabilities = data;
+
+		return 0;
+		}
 	case MSR_EFER:
 		return set_efer(vcpu, msr_info);
 	case MSR_K7_HWCR:
@@ -3197,6 +3211,12 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 			return 1;
 		msr_info->data = vcpu->arch.arch_capabilities;
 		break;
+	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;
+		break;
 	case MSR_IA32_POWER_CTL:
 		msr_info->data = vcpu->arch.msr_ia32_power_ctl;
 		break;