KVM: VMX: Always treat MSR_IA32_PERF_CAPABILITIES as a valid PMU MSR

Unconditionally return true when querying the validity of
MSR_IA32_PERF_CAPABILITIES so as to defer the validity check to
intel_pmu_{get,set}_msr(), which can properly give the MSR a pass when
the access is initiated from host userspace.  The MSR is emulated so
there is no underlying hardware dependency to worry about.

Fixes: 27461da ("KVM: x86/pmu: Support full width counting")
Cc: Like Xu <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

arch/x86/kvm/vmx/pmu_intel.c

@@ -181,7 +181,7 @@ static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
 		ret = pmu->version > 1;
 		break;
 	case MSR_IA32_PERF_CAPABILITIES:
-		ret = guest_cpuid_has(vcpu, X86_FEATURE_PDCM);
+		ret = 1;
 		break;
 	default:
 		ret = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0) ||