[PATCH v4 4/9] KVM: selftests: Test Intel PMU architectural events on gp counters

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From: Jinrong Liang <cloudliang@xxxxxxxxxxx>

Add test cases to check if different Architectural events are available
after it's marked as unavailable via CPUID. It covers vPMU event filtering
logic based on Intel CPUID, which is a complement to pmu_event_filter.

According to Intel SDM, the number of architectural events is reported
through CPUID.0AH:EAX[31:24] and the architectural event x is supported
if EBX[x]=0 && EAX[31:24]>x.

Co-developed-by: Like Xu <likexu@xxxxxxxxxxx>
Signed-off-by: Like Xu <likexu@xxxxxxxxxxx>
Signed-off-by: Jinrong Liang <cloudliang@xxxxxxxxxxx>
---
 tools/testing/selftests/kvm/Makefile          |   1 +
 .../selftests/kvm/x86_64/pmu_counters_test.c  | 182 ++++++++++++++++++
 2 files changed, 183 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/x86_64/pmu_counters_test.c

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 172c4223b286..7768e09de96c 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -81,6 +81,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/mmio_warning_test
 TEST_GEN_PROGS_x86_64 += x86_64/monitor_mwait_test
 TEST_GEN_PROGS_x86_64 += x86_64/nested_exceptions_test
 TEST_GEN_PROGS_x86_64 += x86_64/platform_info_test
+TEST_GEN_PROGS_x86_64 += x86_64/pmu_counters_test
 TEST_GEN_PROGS_x86_64 += x86_64/pmu_event_filter_test
 TEST_GEN_PROGS_x86_64 += x86_64/set_boot_cpu_id
 TEST_GEN_PROGS_x86_64 += x86_64/set_sregs_test
diff --git a/tools/testing/selftests/kvm/x86_64/pmu_counters_test.c b/tools/testing/selftests/kvm/x86_64/pmu_counters_test.c
new file mode 100644
index 000000000000..f47853f3ab84
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86_64/pmu_counters_test.c
@@ -0,0 +1,182 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test the consistency of the PMU's CPUID and its features
+ *
+ * Copyright (C) 2023, Tencent, Inc.
+ *
+ * Check that the VM's PMU behaviour is consistent with the
+ * VM CPUID definition.
+ */
+
+#define _GNU_SOURCE /* for program_invocation_short_name */
+#include <x86intrin.h>
+
+#include "pmu.h"
+#include "processor.h"
+
+/* Guest payload for any performance counter counting */
+#define NUM_BRANCHES		10
+
+static struct kvm_vm *pmu_vm_create_with_one_vcpu(struct kvm_vcpu **vcpu,
+						  void *guest_code)
+{
+	struct kvm_vm *vm;
+
+	vm = vm_create_with_one_vcpu(vcpu, guest_code);
+	vm_init_descriptor_tables(vm);
+	vcpu_init_descriptor_tables(*vcpu);
+
+	return vm;
+}
+
+static void run_vcpu(struct kvm_vcpu *vcpu)
+{
+	struct ucall uc;
+
+	do {
+		vcpu_run(vcpu);
+		switch (get_ucall(vcpu, &uc)) {
+		case UCALL_SYNC:
+			break;
+		case UCALL_ABORT:
+			REPORT_GUEST_ASSERT(uc);
+			break;
+		case UCALL_DONE:
+			break;
+		default:
+			TEST_FAIL("Unexpected ucall: %lu", uc.cmd);
+		}
+	} while (uc.cmd != UCALL_DONE);
+}
+
+static void guest_measure_pmu_v1(uint8_t idx, uint32_t counter_msr,
+				 uint32_t nr_gp_counters, bool expect)
+{
+	unsigned int i;
+
+	for (i = 0; i < nr_gp_counters; i++) {
+		wrmsr(counter_msr + i, 0);
+		wrmsr(MSR_P6_EVNTSEL0 + i, ARCH_PERFMON_EVENTSEL_OS |
+		      ARCH_PERFMON_EVENTSEL_ENABLE |
+		      intel_pmu_arch_events[idx]);
+		__asm__ __volatile__("loop ." : "+c"((int){NUM_BRANCHES}));
+		GUEST_ASSERT_EQ(expect, !!_rdpmc(i));
+
+		wrmsr(MSR_P6_EVNTSEL0 + i, ARCH_PERFMON_EVENTSEL_OS |
+		      !ARCH_PERFMON_EVENTSEL_ENABLE |
+		      intel_pmu_arch_events[idx]);
+		wrmsr(counter_msr + i, 0);
+		__asm__ __volatile__("loop ." : "+c"((int){NUM_BRANCHES}));
+		GUEST_ASSERT(!_rdpmc(i));
+	}
+
+	GUEST_DONE();
+}
+
+static void guest_measure_loop(uint8_t idx)
+{
+	uint32_t nr_gp_counters = this_cpu_property(X86_PROPERTY_PMU_NR_GP_COUNTERS);
+	uint32_t pmu_version = this_cpu_property(X86_PROPERTY_PMU_VERSION);
+	uint32_t counter_msr;
+	unsigned int i;
+	bool expect;
+
+	if (rdmsr(MSR_IA32_PERF_CAPABILITIES) & PMU_CAP_FW_WRITES)
+		counter_msr = MSR_IA32_PMC0;
+	else
+		counter_msr = MSR_IA32_PERFCTR0;
+
+	expect = this_pmu_has_arch_event(KVM_X86_PMU_FEATURE(UNUSED, idx));
+
+	if (pmu_version < 2) {
+		guest_measure_pmu_v1(idx, counter_msr, nr_gp_counters, expect);
+		return;
+	}
+
+	for (i = 0; i < nr_gp_counters; i++) {
+		wrmsr(counter_msr + i, 0);
+		wrmsr(MSR_P6_EVNTSEL0 + i, ARCH_PERFMON_EVENTSEL_OS |
+		      ARCH_PERFMON_EVENTSEL_ENABLE |
+		      intel_pmu_arch_events[idx]);
+
+		wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, BIT_ULL(i));
+		__asm__ __volatile__("loop ." : "+c"((int){NUM_BRANCHES}));
+		wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, 0);
+
+		GUEST_ASSERT_EQ(expect, !!_rdpmc(i));
+	}
+
+	GUEST_DONE();
+}
+
+static void test_arch_events_cpuid(uint8_t i, uint8_t j, uint8_t idx)
+{
+	uint8_t arch_events_unavailable_mask = BIT_ULL(j);
+	uint8_t arch_events_bitmap_size = BIT_ULL(i);
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+
+	vm = pmu_vm_create_with_one_vcpu(&vcpu, guest_measure_loop);
+
+	vcpu_set_cpuid_property(vcpu, X86_PROPERTY_PMU_EBX_BIT_VECTOR_LENGTH,
+				arch_events_bitmap_size);
+	vcpu_set_cpuid_property(vcpu, X86_PROPERTY_PMU_EVENTS_MASK,
+				arch_events_unavailable_mask);
+
+	vcpu_args_set(vcpu, 1, idx);
+
+	run_vcpu(vcpu);
+
+	kvm_vm_free(vm);
+}
+
+static void check_arch_event_is_unavl(uint8_t idx)
+{
+	uint8_t i, j;
+
+	/*
+	 * A brute force iteration of all combinations of values is likely to
+	 * exhaust the limit of the single-threaded thread fd nums, so it's
+	 * tested here by iterating through all valid values on a single bit.
+	 */
+	for (i = 0; i < NR_INTEL_ARCH_EVENTS; i++) {
+		for (j = 0; j < NR_INTEL_ARCH_EVENTS; j++)
+			test_arch_events_cpuid(i, j, idx);
+	}
+}
+
+static void test_intel_arch_events(void)
+{
+	uint8_t idx;
+
+	for (idx = 0; idx < NR_INTEL_ARCH_EVENTS; idx++) {
+		/*
+		 * Given the stability of performance event recurrence, only
+		 * these arch events are currently being tested:
+		 *
+		 * - Core cycle event (idx = 0)
+		 * - Instruction retired event (idx = 1)
+		 * - Reference cycles event (idx = 2)
+		 * - Branch instruction retired event (idx = 5)
+		 */
+		if (idx > INTEL_ARCH_INSTRUCTIONS_RETIRED &&
+		    idx != INTEL_ARCH_BRANCHES_RETIRED)
+			continue;
+
+		check_arch_event_is_unavl(idx);
+	}
+}
+
+int main(int argc, char *argv[])
+{
+	TEST_REQUIRE(get_kvm_param_bool("enable_pmu"));
+
+	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);
+	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_PDCM));
+
+	test_intel_arch_events();
+
+	return 0;
+}
-- 
2.39.3




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