KVM: selftests: Use kvm_cpu_has() for XSAVES in XSS MSR test

Use kvm_cpu_has() in the XSS MSR test instead of open coding equivalent
functionality using kvm_get_supported_cpuid_index().

No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220614200707.3315957-10-seanjc@google.com

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

@@ -112,6 +112,7 @@ struct kvm_x86_cpu_feature {
 #define	X86_FEATURE_SPEC_CTRL		KVM_X86_CPU_FEATURE(0x7, 0, EDX, 26)
 #define	X86_FEATURE_ARCH_CAPABILITIES	KVM_X86_CPU_FEATURE(0x7, 0, EDX, 29)
 #define	X86_FEATURE_PKS			KVM_X86_CPU_FEATURE(0x7, 0, ECX, 31)
+#define	X86_FEATURE_XSAVES		KVM_X86_CPU_FEATURE(0xD, 1, EAX, 3)
 
 /*
  * Extended Leafs, a.k.a. AMD defined

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

@@ -14,11 +14,8 @@
 
 #define MSR_BITS      64
 
-#define X86_FEATURE_XSAVES	(1<<3)
-
 int main(int argc, char *argv[])
 {
-	struct kvm_cpuid_entry2 *entry;
 	bool xss_in_msr_list;
 	struct kvm_vm *vm;
 	struct kvm_vcpu *vcpu;
@@ -28,10 +25,7 @@ int main(int argc, char *argv[])
 	/* Create VM */
 	vm = vm_create_with_one_vcpu(&vcpu, NULL);
 
-	TEST_REQUIRE(kvm_get_cpuid_max_basic() >= 0xd);
-
-	entry = kvm_get_supported_cpuid_index(0xd, 1);
-	TEST_REQUIRE(entry->eax & X86_FEATURE_XSAVES);
+	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_XSAVES));
 
 	xss_val = vcpu_get_msr(vcpu, MSR_IA32_XSS);
 	TEST_ASSERT(xss_val == 0,