KVM: x86: Fix perfctr WRMSR for running counters (4400cf54) · Commits · 戴 / test

Correct the logic in intel_pmu_set_msr() for fixed and general purpose counters. This was recently changed to set pmc->counter without taking in to account the value of pmc_read_counter() which will be incorrect if the counter is currently running and non-zero; this changes back to the old logic which accounted for the value of currently running counters. Signed-off-by:

Eric Hankland <ehankland@google.com> Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx/pmu_intel.c

+4 −5

Original line number	Diff line number	Diff line
		@@ -260,13 +260,12 @@ static int intel_pmu_set_msr(struct kvm_vcpu vcpu, struct msr_data msr_info)
		break;
		default:
		if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0))) {
		if (msr_info->host_initiated)
		pmc->counter = data;
		else
		pmc->counter = (s32)data;
		if (!msr_info->host_initiated)
		data = (s64)(s32)data;
		pmc->counter += data - pmc_read_counter(pmc);
		return 0;
		} else if ((pmc = get_fixed_pmc(pmu, msr))) {
		pmc->counter = data;
		pmc->counter += data - pmc_read_counter(pmc);
		return 0;
		} else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) {
		if (data == pmc->eventsel)

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