KVM: x86/pmu: Ignore pmu->global_ctrl check if vPMU doesn't support global_ctrl

MSR_CORE_PERF_GLOBAL_CTRL is introduced as part of Architecture PMU V2,
as indicated by Intel SDM 19.2.2 and the intel_is_valid_msr() function.

So in the absence of global_ctrl support, all PMCs are enabled as AMD does.

Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20220509102204.62389-1-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx/pmu_intel.c

@@ -98,6 +98,9 @@ static bool intel_pmc_is_enabled(struct kvm_pmc *pmc)
 {
 	struct kvm_pmu *pmu = pmc_to_pmu(pmc);
 
+	if (pmu->version < 2)
+		return true;
+
 	return test_bit(pmc->idx, (unsigned long *)&pmu->global_ctrl);
 }