KVM: selftests: Use kvm_cpu_has() in the SEV migration test

Use kvm_cpu_has() in the SEV migration test instead of open coding
equivalent functionality using kvm_get_supported_cpuid_entry().

No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-5-seanjc@google.com

tools/testing/selftests/kvm/include/x86_64/processor.h

@@ -129,6 +129,8 @@ struct kvm_x86_cpu_feature {
 #define X86_FEATURE_PAUSEFILTER         KVM_X86_CPU_FEATURE(0x8000000A, 0, EDX, 10)
 #define X86_FEATURE_PFTHRESHOLD         KVM_X86_CPU_FEATURE(0x8000000A, 0, EDX, 12)
 #define	X86_FEATURE_VGIF		KVM_X86_CPU_FEATURE(0x8000000A, 0, EDX, 16)
+#define X86_FEATURE_SEV			KVM_X86_CPU_FEATURE(0x8000001F, 0, EAX, 1)
+#define X86_FEATURE_SEV_ES		KVM_X86_CPU_FEATURE(0x8000001F, 0, EAX, 3)
 
 /* CPUID.1.ECX */
 #define CPUID_VMX		(1ul << 5)

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

@@ -393,23 +393,14 @@ static void test_sev_move_copy(void)
 	kvm_vm_free(sev_vm);
 }
 
-#define X86_FEATURE_SEV (1 << 1)
-#define X86_FEATURE_SEV_ES (1 << 3)
-
 int main(int argc, char *argv[])
 {
-	struct kvm_cpuid_entry2 *cpuid;
-
 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM));
 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_VM_COPY_ENC_CONTEXT_FROM));
 
-	cpuid = kvm_get_supported_cpuid_entry(0x80000000);
-	TEST_REQUIRE(cpuid->eax >= 0x8000001f);
-
-	cpuid = kvm_get_supported_cpuid_entry(0x8000001f);
-	TEST_REQUIRE(cpuid->eax & X86_FEATURE_SEV);
+	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_SEV));
 
-	have_sev_es = !!(cpuid->eax & X86_FEATURE_SEV_ES);
+	have_sev_es = kvm_cpu_has(X86_FEATURE_SEV_ES);
 
 	if (kvm_has_cap(KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM)) {
 		test_sev_migrate_from(/* es= */ false);