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[3/6] KVM: x86: selftests: Set up AMD VM in pmu_counters_test

Message ID 20240802182240.1916675-4-coltonlewis@google.com (mailing list archive)
State New, archived
Headers show
Series Extend pmu_counters_test to AMD CPUs | expand

Commit Message

Colton Lewis Aug. 2, 2024, 6:22 p.m. UTC
Branch in main() depending on if the CPU is Intel or AMD. They are
subject to vastly different requirements because the AMD PMU lacks
many properties defined by the Intel PMU including the entire CPUID
0xa function where Intel stores all the PMU properties. AMD lacks this
as well as any consistent notion of PMU versions as Intel does. Every
feature is a separate flag and they aren't the same features as Intel.

Set up a VM for testing core AMD counters and ensure proper CPUID
features are set.

Signed-off-by: Colton Lewis <coltonlewis@google.com>
---
 .../selftests/kvm/x86_64/pmu_counters_test.c  | 80 ++++++++++++++++---
 1 file changed, 68 insertions(+), 12 deletions(-)
diff mbox series

Patch

diff --git a/tools/testing/selftests/kvm/x86_64/pmu_counters_test.c b/tools/testing/selftests/kvm/x86_64/pmu_counters_test.c
index 0e305e43a93b..a11df073331a 100644
--- a/tools/testing/selftests/kvm/x86_64/pmu_counters_test.c
+++ b/tools/testing/selftests/kvm/x86_64/pmu_counters_test.c
@@ -33,7 +33,7 @@ 
 static uint8_t kvm_pmu_version;
 static bool kvm_has_perf_caps;
 
-static struct kvm_vm *pmu_vm_create_with_one_vcpu(struct kvm_vcpu **vcpu,
+static struct kvm_vm *intel_pmu_vm_create(struct kvm_vcpu **vcpu,
 						  void *guest_code,
 						  uint8_t pmu_version,
 						  uint64_t perf_capabilities)
@@ -303,7 +303,7 @@  static void test_arch_events(uint8_t pmu_version, uint64_t perf_capabilities,
 	if (!pmu_version)
 		return;
 
-	vm = pmu_vm_create_with_one_vcpu(&vcpu, guest_test_arch_events,
+	vm = intel_pmu_vm_create(&vcpu, guest_test_arch_events,
 					 pmu_version, perf_capabilities);
 
 	vcpu_set_cpuid_property(vcpu, X86_PROPERTY_PMU_EBX_BIT_VECTOR_LENGTH,
@@ -463,7 +463,7 @@  static void test_gp_counters(uint8_t pmu_version, uint64_t perf_capabilities,
 	struct kvm_vcpu *vcpu;
 	struct kvm_vm *vm;
 
-	vm = pmu_vm_create_with_one_vcpu(&vcpu, guest_test_gp_counters,
+	vm = intel_pmu_vm_create(&vcpu, guest_test_gp_counters,
 					 pmu_version, perf_capabilities);
 
 	vcpu_set_cpuid_property(vcpu, X86_PROPERTY_PMU_NR_GP_COUNTERS,
@@ -530,7 +530,7 @@  static void test_fixed_counters(uint8_t pmu_version, uint64_t perf_capabilities,
 	struct kvm_vcpu *vcpu;
 	struct kvm_vm *vm;
 
-	vm = pmu_vm_create_with_one_vcpu(&vcpu, guest_test_fixed_counters,
+	vm = intel_pmu_vm_create(&vcpu, guest_test_fixed_counters,
 					 pmu_version, perf_capabilities);
 
 	vcpu_set_cpuid_property(vcpu, X86_PROPERTY_PMU_FIXED_COUNTERS_BITMASK,
@@ -627,18 +627,74 @@  static void test_intel_counters(void)
 	}
 }
 
-int main(int argc, char *argv[])
+static uint8_t nr_core_counters(void)
 {
-	TEST_REQUIRE(kvm_is_pmu_enabled());
+	const uint8_t nr_counters = kvm_cpu_property(X86_PROPERTY_NUM_PERF_CTR_CORE);
+	const bool core_ext = kvm_cpu_has(X86_FEATURE_PERF_CTR_EXT_CORE);
+	/* The default numbers promised if the property is 0 */
+	const uint8_t amd_nr_core_ext_counters = 6;
+	const uint8_t amd_nr_core_counters = 4;
+
+	if (nr_counters != 0)
+		return nr_counters;
+
+	if (core_ext)
+		return amd_nr_core_ext_counters;
+
+	return amd_nr_core_counters;
+}
+
+static void guest_test_core_counters(void)
+{
+	GUEST_DONE();
+}
 
-	TEST_REQUIRE(host_cpu_is_intel);
-	TEST_REQUIRE(kvm_cpu_has_p(X86_PROPERTY_PMU_VERSION));
-	TEST_REQUIRE(kvm_cpu_property(X86_PROPERTY_PMU_VERSION) > 0);
+static void test_core_counters(void)
+{
+	uint8_t nr_counters = nr_core_counters();
+	bool core_ext = kvm_cpu_has(X86_FEATURE_PERF_CTR_EXT_CORE);
+	bool perf_mon_v2 = kvm_cpu_has(X86_FEATURE_PERF_MON_V2);
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
 
-	kvm_pmu_version = kvm_cpu_property(X86_PROPERTY_PMU_VERSION);
-	kvm_has_perf_caps = kvm_cpu_has(X86_FEATURE_PDCM);
+	vm = vm_create_with_one_vcpu(&vcpu, guest_test_core_counters);
 
-	test_intel_counters();
+	/* This property may not be there in older underlying CPUs,
+	 * but it simplifies the test code for it to be set
+	 * unconditionally.
+	 */
+	vcpu_set_cpuid_property(vcpu, X86_PROPERTY_NUM_PERF_CTR_CORE, nr_counters);
+	if (core_ext)
+		vcpu_set_cpuid_feature(vcpu, X86_FEATURE_PERF_CTR_EXT_CORE);
+	if (perf_mon_v2)
+		vcpu_set_cpuid_feature(vcpu, X86_FEATURE_PERF_MON_V2);
+
+	pr_info("Testing core counters: CoreExt = %u, PerfMonV2 = %u, NumCounters = %u\n",
+		core_ext, perf_mon_v2, nr_counters);
+	run_vcpu(vcpu);
+
+	kvm_vm_free(vm);
+}
+
+static void test_amd_counters(void)
+{
+	test_core_counters();
+}
+
+int main(int argc, char *argv[])
+{
+	TEST_REQUIRE(kvm_is_pmu_enabled());
+
+	if (host_cpu_is_intel) {
+		TEST_REQUIRE(kvm_cpu_has_p(X86_PROPERTY_PMU_VERSION));
+		TEST_REQUIRE(kvm_cpu_property(X86_PROPERTY_PMU_VERSION) > 0);
+		kvm_pmu_version = kvm_cpu_property(X86_PROPERTY_PMU_VERSION);
+		kvm_has_perf_caps = kvm_cpu_has(X86_FEATURE_PDCM);
+		test_intel_counters();
+	} else if (host_cpu_is_amd) {
+		/* AMD CPUs don't have the same properties to look at. */
+		test_amd_counters();
+	}
 
 	return 0;
 }