Now that KVM disallows changing PERF_CAPABILITIES after KVM_RUN, expand the host side checks to verify KVM rejects any attempts to change bits from userspace. Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> --- .../selftests/kvm/x86_64/vmx_pmu_caps_test.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/tools/testing/selftests/kvm/x86_64/vmx_pmu_caps_test.c b/tools/testing/selftests/kvm/x86_64/vmx_pmu_caps_test.c index 44fc6101a547..6fc86f5eba0b 100644 --- a/tools/testing/selftests/kvm/x86_64/vmx_pmu_caps_test.c +++ b/tools/testing/selftests/kvm/x86_64/vmx_pmu_caps_test.c @@ -85,6 +85,7 @@ static void test_guest_wrmsr_perf_capabilities(union perf_capabilities host_cap) struct kvm_vcpu *vcpu; struct kvm_vm *vm = vm_create_with_one_vcpu(&vcpu, guest_code); struct ucall uc; + int r, i; vm_init_descriptor_tables(vm); vcpu_init_descriptor_tables(vcpu); @@ -106,6 +107,18 @@ static void test_guest_wrmsr_perf_capabilities(union perf_capabilities host_cap) ASSERT_EQ(vcpu_get_msr(vcpu, MSR_IA32_PERF_CAPABILITIES), host_cap.capabilities); + vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, host_cap.capabilities); + + r = _vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, 0); + TEST_ASSERT(!r, "Post-KVM_RUN write '0' didn't fail"); + + for (i = 0; i < 64; i++) { + r = _vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, + host_cap.capabilities ^ BIT_ULL(i)); + TEST_ASSERT(!r, "Post-KVM_RUN write '0x%llx'didn't fail", + host_cap.capabilities ^ BIT_ULL(i)); + } + kvm_vm_free(vm); } -- 2.40.0.rc1.284.g88254d51c5-goog