KVM: ignore reads to perfctr msrs

We ignore writes to the perfctr msrs. Ignore reads as well.

Kaspersky antivirus crashes Windows guests if it can't read
these MSRs.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 92b5edd..132c510 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1048,9 +1048,12 @@
 	case MSR_K8_SYSCFG:
 	case MSR_K7_HWCR:
 	case MSR_VM_HSAVE_PA:
+	case MSR_P6_PERFCTR0:
+	case MSR_P6_PERFCTR1:
 	case MSR_P6_EVNTSEL0:
 	case MSR_P6_EVNTSEL1:
 	case MSR_K7_EVNTSEL0:
+	case MSR_K7_PERFCTR0:
 	case MSR_K8_INT_PENDING_MSG:
 	case MSR_AMD64_NB_CFG:
 	case MSR_FAM10H_MMIO_CONF_BASE: