Commit 81fd9241 authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: selftests: Test post-KVM_RUN writes to PERF_CAPABILITIES 

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.

Link: https://lore.kernel.org/r/20230311004618.920745-18-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent baa36dac

tools/testing/selftests/kvm/x86_64/vmx_pmu_caps_test.c

+13 −0
Original line number Diff line number Diff line
@@ -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);

}