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 +
.../kvm/x86_64/pmu_basic_functionality_test.c | 158 ++++++++++++++++++
2 files changed, 159 insertions(+)
create mode 100644 tools/testing/selftests/kvm/x86_64/pmu_basic_functionality_test.c
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 77026907968f..965a36562ef8 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -80,6 +80,7 @@ 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_basic_functionality_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_basic_functionality_test.c b/tools/testing/selftests/kvm/x86_64/pmu_basic_functionality_test.c
new file mode 100644
index 000000000000..c04eb0bdf69f
--- /dev/null
+++ b/tools/testing/selftests/kvm/x86_64/pmu_basic_functionality_test.c
@@ -0,0 +1,158 @@
+// 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"
+
+/* 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 uint64_t run_vcpu(struct kvm_vcpu *vcpu, uint64_t *ucall_arg)
+{
+ struct ucall uc;
+
+ vcpu_run(vcpu);
+ switch (get_ucall(vcpu, &uc)) {
+ case UCALL_SYNC:
+ *ucall_arg = uc.args[1];
+ break;
+ case UCALL_DONE:
+ break;
+ default:
+ TEST_FAIL("Unexpected ucall: %lu", uc.cmd);
+ }
+ return uc.cmd;
+}
+
+static void guest_measure_loop(uint64_t event_code)
+{
+ 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;
+
+ if (rdmsr(MSR_IA32_PERF_CAPABILITIES) & PMU_CAP_FW_WRITES)
+ counter_msr = MSR_IA32_PMC0;
+ else
+ counter_msr = MSR_IA32_PERFCTR0;
+
+ 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 | event_code);
+
+ if (pmu_version > 1) {
+ wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, BIT_ULL(i));
+ __asm__ __volatile__("loop ." : "+c"((int){NUM_BRANCHES}));
+ wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, 0);
+ GUEST_SYNC(_rdpmc(i));
+ } else {
+ __asm__ __volatile__("loop ." : "+c"((int){NUM_BRANCHES}));
+ GUEST_SYNC(_rdpmc(i));
+ }
+ }
+
+ GUEST_DONE();
+}
+
+static void test_arch_events_cpuid(struct kvm_vcpu *vcpu,
+ uint8_t arch_events_bitmap_size,
+ uint8_t arch_events_unavailable_mask,
+ uint8_t idx)
+{
+ uint64_t counter_val = 0;
+ bool is_supported;
+
+ 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);
+
+ is_supported = arch_event_is_supported(vcpu, idx);
+ vcpu_args_set(vcpu, 1, intel_arch_events[idx]);
+
+ while (run_vcpu(vcpu, &counter_val) != UCALL_DONE)
+ TEST_ASSERT_EQ(is_supported, !!counter_val);
+}
+
+static void intel_check_arch_event_is_unavl(uint8_t idx)
+{
+ uint8_t eax_evt_vec, ebx_unavl_mask, i, j;
+ struct kvm_vcpu *vcpu;
+ struct kvm_vm *vm;
+
+ /*
+ * 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 < ARRAY_SIZE(intel_arch_events); i++) {
+ eax_evt_vec = BIT_ULL(i);
+ for (j = 0; j < ARRAY_SIZE(intel_arch_events); j++) {
+ ebx_unavl_mask = BIT_ULL(j);
+ vm = pmu_vm_create_with_one_vcpu(&vcpu,
+ guest_measure_loop);
+ test_arch_events_cpuid(vcpu, eax_evt_vec,
+ ebx_unavl_mask, idx);
+
+ kvm_vm_free(vm);
+ }
+ }
+}
+
+static void intel_test_arch_events(void)
+{
+ uint8_t idx;
+
+ for (idx = 0; idx < ARRAY_SIZE(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;
+
+ intel_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));
+
+ intel_test_arch_events();
+
+ return 0;
+}
--
2.39.3
