From: Liran Alon liran.alon@oracle.com
[ Upstream commit 672ff6cff80ca43bf3258410d2b887036969df5f ]
Before this change, reading a VMware pseduo PMC will succeed even when PMU is not supported by guest. This can easily be seen by running kvm-unit-test vmware_backdoors with "-cpu host,-pmu" option.
Reviewed-by: Mihai Carabas mihai.carabas@oracle.com Signed-off-by: Liran Alon liran.alon@oracle.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/kvm/pmu.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index 58ead7db71a3..e39741997893 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -281,9 +281,13 @@ static int kvm_pmu_rdpmc_vmware(struct kvm_vcpu *vcpu, unsigned idx, u64 *data) int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned idx, u64 *data) { bool fast_mode = idx & (1u << 31); + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); struct kvm_pmc *pmc; u64 ctr_val;
+ if (!pmu->version) + return 1; + if (is_vmware_backdoor_pmc(idx)) return kvm_pmu_rdpmc_vmware(vcpu, idx, data);