Commit 710fb612 authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: selftests: Move 0/initial value PERF_CAPS checks to dedicated sub-test 

Use a separate sub-test to verify userspace can clear PERF_CAPABILITIES
and restore it to the KVM-supported value, as the testcase isn't unique
to the LBR format.

Link: https://lore.kernel.org/r/20230311004618.920745-10-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 957d0f70

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

+19 −6
Original line number Diff line number Diff line
@@ -41,6 +41,24 @@ static void guest_code(void) 
	wrmsr(MSR_IA32_PERF_CAPABILITIES, PMU_CAP_LBR_FMT);

}



/*

 * Verify KVM allows writing PERF_CAPABILITIES with all KVM-supported features

 * enabled, as well as '0' (to disable all features).

 */

static void test_basic_perf_capabilities(union perf_capabilities host_cap)

{

	struct kvm_vcpu *vcpu;

	struct kvm_vm *vm = vm_create_with_one_vcpu(&vcpu, NULL);



	vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, 0);

	ASSERT_EQ(vcpu_get_msr(vcpu, MSR_IA32_PERF_CAPABILITIES), 0);



	vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, host_cap.capabilities);

	ASSERT_EQ(vcpu_get_msr(vcpu, MSR_IA32_PERF_CAPABILITIES), host_cap.capabilities);



	kvm_vm_free(vm);

}



static void test_fungible_perf_capabilities(union perf_capabilities host_cap)

{

	struct kvm_vcpu *vcpu;
@@ -66,12 +84,6 @@ static void test_immutable_perf_capabilities(union perf_capabilities host_cap) 
	uint64_t val;

	int ret;



	vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, 0);

	ASSERT_EQ(vcpu_get_msr(vcpu, MSR_IA32_PERF_CAPABILITIES), 0);



	vcpu_set_msr(vcpu, MSR_IA32_PERF_CAPABILITIES, host_cap.lbr_format);

	ASSERT_EQ(vcpu_get_msr(vcpu, MSR_IA32_PERF_CAPABILITIES), (u64)host_cap.lbr_format);



	/*

	 * KVM only supports the host's native LBR format, as well as '0' (to

	 * disable LBR support).  Verify KVM rejects all other LBR formats.
@@ -98,6 +110,7 @@ int main(int argc, char *argv[]) 
	host_cap.capabilities = kvm_get_feature_msr(MSR_IA32_PERF_CAPABILITIES);

	host_cap.capabilities &= (PMU_CAP_FW_WRITES | PMU_CAP_LBR_FMT);



	test_basic_perf_capabilities(host_cap);

	test_fungible_perf_capabilities(host_cap);

	test_immutable_perf_capabilities(host_cap);