This is a note to let you know that I've just added the patch titled
KVM: x86/pmu: Accept 0 for absent PMU MSRs when host-initiated if !enable_pmu
to the 5.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-x86-pmu-accept-0-for-absent-pmu-msrs-when-host-i.patch
and it can be found in the queue-5.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a056ce6a166845c496ed36a12d7d5933069164a3
Author: Like Xu <likexu@xxxxxxxxxxx>
Date: Wed Jun 1 11:19:23 2022 +0800
KVM: x86/pmu: Accept 0 for absent PMU MSRs when host-initiated if !enable_pmu
[ Upstream commit 8e6a58e28b34e8d247e772159b8fa8f6bae39192 ]
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: Like Xu <likexu@xxxxxxxxxxx>
Message-Id: <20220601031925.59693-1-likexu@xxxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 3f868fed9114..2334ddfbbab2 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -433,11 +433,19 @@ 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);
}
diff --git a/arch/x86/kvm/svm/pmu.c b/arch/x86/kvm/svm/pmu.c
index 136039fc6d01..d93ecb25fe17 100644
--- a/arch/x86/kvm/svm/pmu.c
+++ b/arch/x86/kvm/svm/pmu.c
@@ -232,7 +232,16 @@ 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)
{
/* All MSRs refer to exactly one PMC, so msr_idx_to_pmc is enough. */
- return false;
+ 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)
