KVM: x86/vPMU: Forbid reading from MSR_F15H_PERF MSRs when guest doesn't have X86_FEA...

MSR_F15H_PERF_CTL0-5, MSR_F15H_PERF_CTR0-5 MSRs have a CPUID bit assigned
to them (X86_FEATURE_PERFCTR_CORE) and when it wasn't exposed to the guest
the correct behavior is to inject #GP an not just return zero.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210329124804.170173-1-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a9d95f9..79a5d5e 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3407,6 +3407,12 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
                msr_info->data = 0;
                break;
        case MSR_F15H_PERF_CTL0 ... MSR_F15H_PERF_CTR5:
+               if (kvm_pmu_is_valid_msr(vcpu, msr_info->index))
+                       return kvm_pmu_get_msr(vcpu, msr_info);
+               if (!msr_info->host_initiated)
+                       return 1;
+               msr_info->data = 0;
+               break;
        case MSR_K7_EVNTSEL0 ... MSR_K7_EVNTSEL3:
        case MSR_K7_PERFCTR0 ... MSR_K7_PERFCTR3:
        case MSR_P6_PERFCTR0 ... MSR_P6_PERFCTR1: