diff options
Diffstat (limited to 'tools/testing/selftests/kvm/x86/pmu_counters_test.c')
| -rw-r--r-- | tools/testing/selftests/kvm/x86/pmu_counters_test.c | 158 |
1 files changed, 91 insertions, 67 deletions
diff --git a/tools/testing/selftests/kvm/x86/pmu_counters_test.c b/tools/testing/selftests/kvm/x86/pmu_counters_test.c index 698cb36989db..8aaaf25b6111 100644 --- a/tools/testing/selftests/kvm/x86/pmu_counters_test.c +++ b/tools/testing/selftests/kvm/x86/pmu_counters_test.c @@ -17,7 +17,7 @@ * Number of instructions in each loop. 1 CLFLUSH/CLFLUSHOPT/NOP, 1 MFENCE, * 1 LOOP. */ -#define NUM_INSNS_PER_LOOP 3 +#define NUM_INSNS_PER_LOOP 4 /* * Number of "extra" instructions that will be counted, i.e. the number of @@ -29,10 +29,59 @@ /* Total number of instructions retired within the measured section. */ #define NUM_INSNS_RETIRED (NUM_LOOPS * NUM_INSNS_PER_LOOP + NUM_EXTRA_INSNS) +/* Track which architectural events are supported by hardware. */ +static uint32_t hardware_pmu_arch_events; static uint8_t kvm_pmu_version; static bool kvm_has_perf_caps; +#define X86_PMU_FEATURE_NULL \ +({ \ + struct kvm_x86_pmu_feature feature = {}; \ + \ + feature; \ +}) + +static bool pmu_is_null_feature(struct kvm_x86_pmu_feature event) +{ + return !(*(u64 *)&event); +} + +struct kvm_intel_pmu_event { + struct kvm_x86_pmu_feature gp_event; + struct kvm_x86_pmu_feature fixed_event; +}; + +/* + * Wrap the array to appease the compiler, as the macros used to construct each + * kvm_x86_pmu_feature use syntax that's only valid in function scope, and the + * compiler often thinks the feature definitions aren't compile-time constants. + */ +static struct kvm_intel_pmu_event intel_event_to_feature(uint8_t idx) +{ + const struct kvm_intel_pmu_event __intel_event_to_feature[] = { + [INTEL_ARCH_CPU_CYCLES_INDEX] = { X86_PMU_FEATURE_CPU_CYCLES, X86_PMU_FEATURE_CPU_CYCLES_FIXED }, + [INTEL_ARCH_INSTRUCTIONS_RETIRED_INDEX] = { X86_PMU_FEATURE_INSNS_RETIRED, X86_PMU_FEATURE_INSNS_RETIRED_FIXED }, + /* + * Note, the fixed counter for reference cycles is NOT the same as the + * general purpose architectural event. The fixed counter explicitly + * counts at the same frequency as the TSC, whereas the GP event counts + * at a fixed, but uarch specific, frequency. Bundle them here for + * simplicity. + */ + [INTEL_ARCH_REFERENCE_CYCLES_INDEX] = { X86_PMU_FEATURE_REFERENCE_CYCLES, X86_PMU_FEATURE_REFERENCE_TSC_CYCLES_FIXED }, + [INTEL_ARCH_LLC_REFERENCES_INDEX] = { X86_PMU_FEATURE_LLC_REFERENCES, X86_PMU_FEATURE_NULL }, + [INTEL_ARCH_LLC_MISSES_INDEX] = { X86_PMU_FEATURE_LLC_MISSES, X86_PMU_FEATURE_NULL }, + [INTEL_ARCH_BRANCHES_RETIRED_INDEX] = { X86_PMU_FEATURE_BRANCH_INSNS_RETIRED, X86_PMU_FEATURE_NULL }, + [INTEL_ARCH_BRANCHES_MISPREDICTED_INDEX] = { X86_PMU_FEATURE_BRANCHES_MISPREDICTED, X86_PMU_FEATURE_NULL }, + [INTEL_ARCH_TOPDOWN_SLOTS_INDEX] = { X86_PMU_FEATURE_TOPDOWN_SLOTS, X86_PMU_FEATURE_TOPDOWN_SLOTS_FIXED }, + }; + + kvm_static_assert(ARRAY_SIZE(__intel_event_to_feature) == NR_INTEL_ARCH_EVENTS); + + return __intel_event_to_feature[idx]; +} + static struct kvm_vm *pmu_vm_create_with_one_vcpu(struct kvm_vcpu **vcpu, void *guest_code, uint8_t pmu_version, @@ -42,6 +91,7 @@ static struct kvm_vm *pmu_vm_create_with_one_vcpu(struct kvm_vcpu **vcpu, vm = vm_create_with_one_vcpu(vcpu, guest_code); sync_global_to_guest(vm, kvm_pmu_version); + sync_global_to_guest(vm, hardware_pmu_arch_events); /* * Set PERF_CAPABILITIES before PMU version as KVM disallows enabling @@ -98,14 +148,12 @@ static uint8_t guest_get_pmu_version(void) * Sanity check that in all cases, the event doesn't count when it's disabled, * and that KVM correctly emulates the write of an arbitrary value. */ -static void guest_assert_event_count(uint8_t idx, - struct kvm_x86_pmu_feature event, - uint32_t pmc, uint32_t pmc_msr) +static void guest_assert_event_count(uint8_t idx, uint32_t pmc, uint32_t pmc_msr) { uint64_t count; count = _rdpmc(pmc); - if (!this_pmu_has(event)) + if (!(hardware_pmu_arch_events & BIT(idx))) goto sanity_checks; switch (idx) { @@ -126,7 +174,9 @@ static void guest_assert_event_count(uint8_t idx, GUEST_ASSERT_NE(count, 0); break; case INTEL_ARCH_TOPDOWN_SLOTS_INDEX: - GUEST_ASSERT(count >= NUM_INSNS_RETIRED); + __GUEST_ASSERT(count >= NUM_INSNS_RETIRED, + "Expected top-down slots >= %u, got count = %lu", + NUM_INSNS_RETIRED, count); break; default: break; @@ -162,75 +212,42 @@ do { \ "1:\n\t" \ clflush "\n\t" \ "mfence\n\t" \ + "mov %[m], %%eax\n\t" \ FEP "loop 1b\n\t" \ FEP "mov %%edi, %%ecx\n\t" \ FEP "xor %%eax, %%eax\n\t" \ FEP "xor %%edx, %%edx\n\t" \ "wrmsr\n\t" \ :: "a"((uint32_t)_value), "d"(_value >> 32), \ - "c"(_msr), "D"(_msr) \ + "c"(_msr), "D"(_msr), [m]"m"(kvm_pmu_version) \ ); \ } while (0) -#define GUEST_TEST_EVENT(_idx, _event, _pmc, _pmc_msr, _ctrl_msr, _value, FEP) \ +#define GUEST_TEST_EVENT(_idx, _pmc, _pmc_msr, _ctrl_msr, _value, FEP) \ do { \ - wrmsr(pmc_msr, 0); \ + wrmsr(_pmc_msr, 0); \ \ if (this_cpu_has(X86_FEATURE_CLFLUSHOPT)) \ - GUEST_MEASURE_EVENT(_ctrl_msr, _value, "clflushopt .", FEP); \ + GUEST_MEASURE_EVENT(_ctrl_msr, _value, "clflushopt %[m]", FEP); \ else if (this_cpu_has(X86_FEATURE_CLFLUSH)) \ - GUEST_MEASURE_EVENT(_ctrl_msr, _value, "clflush .", FEP); \ + GUEST_MEASURE_EVENT(_ctrl_msr, _value, "clflush %[m]", FEP); \ else \ GUEST_MEASURE_EVENT(_ctrl_msr, _value, "nop", FEP); \ \ - guest_assert_event_count(_idx, _event, _pmc, _pmc_msr); \ + guest_assert_event_count(_idx, _pmc, _pmc_msr); \ } while (0) -static void __guest_test_arch_event(uint8_t idx, struct kvm_x86_pmu_feature event, - uint32_t pmc, uint32_t pmc_msr, +static void __guest_test_arch_event(uint8_t idx, uint32_t pmc, uint32_t pmc_msr, uint32_t ctrl_msr, uint64_t ctrl_msr_value) { - GUEST_TEST_EVENT(idx, event, pmc, pmc_msr, ctrl_msr, ctrl_msr_value, ""); + GUEST_TEST_EVENT(idx, pmc, pmc_msr, ctrl_msr, ctrl_msr_value, ""); if (is_forced_emulation_enabled) - GUEST_TEST_EVENT(idx, event, pmc, pmc_msr, ctrl_msr, ctrl_msr_value, KVM_FEP); -} - -#define X86_PMU_FEATURE_NULL \ -({ \ - struct kvm_x86_pmu_feature feature = {}; \ - \ - feature; \ -}) - -static bool pmu_is_null_feature(struct kvm_x86_pmu_feature event) -{ - return !(*(u64 *)&event); + GUEST_TEST_EVENT(idx, pmc, pmc_msr, ctrl_msr, ctrl_msr_value, KVM_FEP); } static void guest_test_arch_event(uint8_t idx) { - const struct { - struct kvm_x86_pmu_feature gp_event; - struct kvm_x86_pmu_feature fixed_event; - } intel_event_to_feature[] = { - [INTEL_ARCH_CPU_CYCLES_INDEX] = { X86_PMU_FEATURE_CPU_CYCLES, X86_PMU_FEATURE_CPU_CYCLES_FIXED }, - [INTEL_ARCH_INSTRUCTIONS_RETIRED_INDEX] = { X86_PMU_FEATURE_INSNS_RETIRED, X86_PMU_FEATURE_INSNS_RETIRED_FIXED }, - /* - * Note, the fixed counter for reference cycles is NOT the same - * as the general purpose architectural event. The fixed counter - * explicitly counts at the same frequency as the TSC, whereas - * the GP event counts at a fixed, but uarch specific, frequency. - * Bundle them here for simplicity. - */ - [INTEL_ARCH_REFERENCE_CYCLES_INDEX] = { X86_PMU_FEATURE_REFERENCE_CYCLES, X86_PMU_FEATURE_REFERENCE_TSC_CYCLES_FIXED }, - [INTEL_ARCH_LLC_REFERENCES_INDEX] = { X86_PMU_FEATURE_LLC_REFERENCES, X86_PMU_FEATURE_NULL }, - [INTEL_ARCH_LLC_MISSES_INDEX] = { X86_PMU_FEATURE_LLC_MISSES, X86_PMU_FEATURE_NULL }, - [INTEL_ARCH_BRANCHES_RETIRED_INDEX] = { X86_PMU_FEATURE_BRANCH_INSNS_RETIRED, X86_PMU_FEATURE_NULL }, - [INTEL_ARCH_BRANCHES_MISPREDICTED_INDEX] = { X86_PMU_FEATURE_BRANCHES_MISPREDICTED, X86_PMU_FEATURE_NULL }, - [INTEL_ARCH_TOPDOWN_SLOTS_INDEX] = { X86_PMU_FEATURE_TOPDOWN_SLOTS, X86_PMU_FEATURE_TOPDOWN_SLOTS_FIXED }, - }; - uint32_t nr_gp_counters = this_cpu_property(X86_PROPERTY_PMU_NR_GP_COUNTERS); uint32_t pmu_version = guest_get_pmu_version(); /* PERF_GLOBAL_CTRL exists only for Architectural PMU Version 2+. */ @@ -248,7 +265,7 @@ static void guest_test_arch_event(uint8_t idx) else base_pmc_msr = MSR_IA32_PERFCTR0; - gp_event = intel_event_to_feature[idx].gp_event; + gp_event = intel_event_to_feature(idx).gp_event; GUEST_ASSERT_EQ(idx, gp_event.f.bit); GUEST_ASSERT(nr_gp_counters); @@ -262,14 +279,14 @@ static void guest_test_arch_event(uint8_t idx) if (guest_has_perf_global_ctrl) wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, BIT_ULL(i)); - __guest_test_arch_event(idx, gp_event, i, base_pmc_msr + i, + __guest_test_arch_event(idx, i, base_pmc_msr + i, MSR_P6_EVNTSEL0 + i, eventsel); } if (!guest_has_perf_global_ctrl) return; - fixed_event = intel_event_to_feature[idx].fixed_event; + fixed_event = intel_event_to_feature(idx).fixed_event; if (pmu_is_null_feature(fixed_event) || !this_pmu_has(fixed_event)) return; @@ -277,7 +294,7 @@ static void guest_test_arch_event(uint8_t idx) wrmsr(MSR_CORE_PERF_FIXED_CTR_CTRL, FIXED_PMC_CTRL(i, FIXED_PMC_KERNEL)); - __guest_test_arch_event(idx, fixed_event, i | INTEL_RDPMC_FIXED, + __guest_test_arch_event(idx, i | INTEL_RDPMC_FIXED, MSR_CORE_PERF_FIXED_CTR0 + i, MSR_CORE_PERF_GLOBAL_CTRL, FIXED_PMC_GLOBAL_CTRL_ENABLE(i)); @@ -331,9 +348,9 @@ __GUEST_ASSERT(expect_gp ? vector == GP_VECTOR : !vector, \ expect_gp ? "#GP" : "no fault", msr, vector) \ #define GUEST_ASSERT_PMC_VALUE(insn, msr, val, expected) \ - __GUEST_ASSERT(val == expected_val, \ + __GUEST_ASSERT(val == expected, \ "Expected " #insn "(0x%x) to yield 0x%lx, got 0x%lx", \ - msr, expected_val, val); + msr, expected, val); static void guest_test_rdpmc(uint32_t rdpmc_idx, bool expect_success, uint64_t expected_val) @@ -545,7 +562,6 @@ static void test_fixed_counters(uint8_t pmu_version, uint64_t perf_capabilities, static void test_intel_counters(void) { - uint8_t nr_arch_events = kvm_cpu_property(X86_PROPERTY_PMU_EBX_BIT_VECTOR_LENGTH); uint8_t nr_fixed_counters = kvm_cpu_property(X86_PROPERTY_PMU_NR_FIXED_COUNTERS); uint8_t nr_gp_counters = kvm_cpu_property(X86_PROPERTY_PMU_NR_GP_COUNTERS); uint8_t pmu_version = kvm_cpu_property(X86_PROPERTY_PMU_VERSION); @@ -567,18 +583,26 @@ static void test_intel_counters(void) /* * Detect the existence of events that aren't supported by selftests. - * This will (obviously) fail any time the kernel adds support for a - * new event, but it's worth paying that price to keep the test fresh. + * This will (obviously) fail any time hardware adds support for a new + * event, but it's worth paying that price to keep the test fresh. */ - TEST_ASSERT(nr_arch_events <= NR_INTEL_ARCH_EVENTS, + TEST_ASSERT(this_cpu_property(X86_PROPERTY_PMU_EBX_BIT_VECTOR_LENGTH) <= NR_INTEL_ARCH_EVENTS, "New architectural event(s) detected; please update this test (length = %u, mask = %x)", - nr_arch_events, kvm_cpu_property(X86_PROPERTY_PMU_EVENTS_MASK)); + this_cpu_property(X86_PROPERTY_PMU_EBX_BIT_VECTOR_LENGTH), + this_cpu_property(X86_PROPERTY_PMU_EVENTS_MASK)); /* - * Force iterating over known arch events regardless of whether or not - * KVM/hardware supports a given event. + * Iterate over known arch events irrespective of KVM/hardware support + * to verify that KVM doesn't reject programming of events just because + * the *architectural* encoding is unsupported. Track which events are + * supported in hardware; the guest side will validate supported events + * count correctly, even if *enumeration* of the event is unsupported + * by KVM and/or isn't exposed to the guest. */ - nr_arch_events = max_t(typeof(nr_arch_events), nr_arch_events, NR_INTEL_ARCH_EVENTS); + for (i = 0; i < NR_INTEL_ARCH_EVENTS; i++) { + if (this_pmu_has(intel_event_to_feature(i).gp_event)) + hardware_pmu_arch_events |= BIT(i); + } for (v = 0; v <= max_pmu_version; v++) { for (i = 0; i < ARRAY_SIZE(perf_caps); i++) { @@ -594,8 +618,8 @@ static void test_intel_counters(void) * vector length. */ if (v == pmu_version) { - for (k = 1; k < (BIT(nr_arch_events) - 1); k++) - test_arch_events(v, perf_caps[i], nr_arch_events, k); + for (k = 1; k < (BIT(NR_INTEL_ARCH_EVENTS) - 1); k++) + test_arch_events(v, perf_caps[i], NR_INTEL_ARCH_EVENTS, k); } /* * Test single bits for all PMU version and lengths up @@ -604,11 +628,11 @@ static void test_intel_counters(void) * host length). Explicitly test a mask of '0' and all * ones i.e. all events being available and unavailable. */ - for (j = 0; j <= nr_arch_events + 1; j++) { + for (j = 0; j <= NR_INTEL_ARCH_EVENTS + 1; j++) { test_arch_events(v, perf_caps[i], j, 0); test_arch_events(v, perf_caps[i], j, 0xff); - for (k = 0; k < nr_arch_events; k++) + for (k = 0; k < NR_INTEL_ARCH_EVENTS; k++) test_arch_events(v, perf_caps[i], j, BIT(k)); } |