Commit 8e6a58e2 authored by Like Xu's avatar Like Xu Committed by Paolo Bonzini
Browse files

KVM: x86/pmu: Accept 0 for absent PMU MSRs when host-initiated if !enable_pmu 



Whenever an MSR is part of KVM_GET_MSR_INDEX_LIST, as is the case for
MSR_K7_EVNTSEL0 or MSR_F15H_PERF_CTL0, it has to be always retrievable
and settable with KVM_GET_MSR and KVM_SET_MSR.

Accept a zero value for these MSRs to obey the contract.

Signed-off-by: default avatarLike Xu <likexu@tencent.com>
Message-Id: <20220601031925.59693-1-likexu@tencent.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 6ef25aa0

arch/x86/kvm/pmu.c

+8 −0
Original line number Diff line number Diff line
@@ -442,11 +442,19 @@ static void kvm_pmu_mark_pmc_in_use(struct kvm_vcpu *vcpu, u32 msr) 


int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)

{

	if (msr_info->host_initiated && !vcpu->kvm->arch.enable_pmu) {

		msr_info->data = 0;

		return 0;

	}



	return static_call(kvm_x86_pmu_get_msr)(vcpu, msr_info);

}



int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)

{

	if (msr_info->host_initiated && !vcpu->kvm->arch.enable_pmu)

		return !!msr_info->data;



	kvm_pmu_mark_pmc_in_use(vcpu, msr_info->index);

	return static_call(kvm_x86_pmu_set_msr)(vcpu, msr_info);

}

arch/x86/kvm/svm/pmu.c

+10 −1
Original line number Diff line number Diff line
@@ -182,7 +182,16 @@ static struct kvm_pmc *amd_rdpmc_ecx_to_pmc(struct kvm_vcpu *vcpu, 
static bool amd_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr, bool host_initiated)

{

	/* All MSRs refer to exactly one PMC, so msr_idx_to_pmc is enough.  */

	if (!host_initiated)

		return false;



	switch (msr) {

	case MSR_K7_EVNTSEL0 ... MSR_K7_PERFCTR3:

	case MSR_F15H_PERF_CTL0 ... MSR_F15H_PERF_CTR5:

		return true;

	default:

		return false;

	}

}



static struct kvm_pmc *amd_msr_idx_to_pmc(struct kvm_vcpu *vcpu, u32 msr)