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authorSean Christopherson <seanjc@google.com>2023-03-10 16:46:04 -0800
committerSean Christopherson <seanjc@google.com>2023-04-06 14:58:43 -0700
commit3a6de51a437fb4d2433f8a99fb59f43866cdbb98 (patch)
tree1371bd9dfa246de0d6a82829b7c535e6a6eb61c4 /arch/x86/kvm/pmu.c
parent0094f62c7eaaaf53a011a4e46f9f32e5f3295e8c (diff)
KVM: x86/pmu: WARN and bug the VM if PMU is refreshed after vCPU has run
Now that KVM disallows changing feature MSRs, i.e. PERF_CAPABILITIES, after running a vCPU, WARN and bug the VM if the PMU is refreshed after the vCPU has run. Note, KVM has disallowed CPUID updates after running a vCPU since commit feb627e8d6f6 ("KVM: x86: Forbid KVM_SET_CPUID{,2} after KVM_RUN"), i.e. PERF_CAPABILITIES was the only remaining way to trigger a PMU refresh after KVM_RUN. Cc: Like Xu <like.xu.linux@gmail.com> Link: https://lore.kernel.org/r/20230311004618.920745-8-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/x86/kvm/pmu.c')
-rw-r--r--arch/x86/kvm/pmu.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index 29492c2a0c82..136184fe9e92 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -589,6 +589,9 @@ int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
*/
void kvm_pmu_refresh(struct kvm_vcpu *vcpu)
{
+ if (KVM_BUG_ON(kvm_vcpu_has_run(vcpu), vcpu->kvm))
+ return;
+
bitmap_zero(vcpu_to_pmu(vcpu)->all_valid_pmc_idx, X86_PMC_IDX_MAX);
static_call(kvm_x86_pmu_refresh)(vcpu);
}