KVM: selftests: Use kvm_cpu_has() to query PDCM in PMU selftest

Use kvm_cpu_has() in the PMU test to query PDCM support 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/20220614200707.3315957-8-seanjc@google.com

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

@@ -81,6 +81,7 @@ struct kvm_x86_cpu_feature {
 #define	X86_FEATURE_MWAIT		KVM_X86_CPU_FEATURE(0x1, 0, ECX, 3)
 #define	X86_FEATURE_VMX			KVM_X86_CPU_FEATURE(0x1, 0, ECX, 5)
 #define	X86_FEATURE_SMX			KVM_X86_CPU_FEATURE(0x1, 0, ECX, 6)
+#define	X86_FEATURE_PDCM		KVM_X86_CPU_FEATURE(0x1, 0, ECX, 15)
 #define	X86_FEATURE_PCID		KVM_X86_CPU_FEATURE(0x1, 0, ECX, 17)
 #define	X86_FEATURE_MOVBE		KVM_X86_CPU_FEATURE(0x1, 0, ECX, 22)
 #define	X86_FEATURE_TSC_DEADLINE_TIMER	KVM_X86_CPU_FEATURE(0x1, 0, ECX, 24)

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

@@ -17,7 +17,6 @@
 #include "kvm_util.h"
 #include "vmx.h"
 
-#define X86_FEATURE_PDCM	(1<<15)
 #define PMU_CAP_FW_WRITES	(1ULL << 13)
 #define PMU_CAP_LBR_FMT		0x3f
 
@@ -55,7 +54,6 @@ static void guest_code(void)
 int main(int argc, char *argv[])
 {
 	struct kvm_cpuid2 *cpuid;
-	struct kvm_cpuid_entry2 *entry_1_0;
 	struct kvm_cpuid_entry2 *entry_a_0;
 	struct kvm_vm *vm;
 	struct kvm_vcpu *vcpu;
@@ -70,11 +68,10 @@ int main(int argc, char *argv[])
 	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
 	cpuid = kvm_get_supported_cpuid();
 
-	TEST_REQUIRE(kvm_get_cpuid_max_basic() >= 0xa);
+	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_PDCM));
 
-	entry_1_0 = kvm_get_supported_cpuid_index(1, 0);
+	TEST_REQUIRE(kvm_get_cpuid_max_basic() >= 0xa);
 	entry_a_0 = kvm_get_supported_cpuid_index(0xa, 0);
-	TEST_REQUIRE(entry_1_0->ecx & X86_FEATURE_PDCM);
 
 	eax.full = entry_a_0->eax;
 	__TEST_REQUIRE(eax.split.version_id, "PMU is not supported by the vCPU");