diff options
| -rw-r--r-- | tools/testing/selftests/kvm/include/x86/pmu.h | 16 | ||||
| -rw-r--r-- | tools/testing/selftests/kvm/lib/x86/pmu.c | 44 | ||||
| -rw-r--r-- | tools/testing/selftests/kvm/lib/x86/processor.c | 4 | ||||
| -rw-r--r-- | tools/testing/selftests/kvm/x86/pmu_counters_test.c | 12 | ||||
| -rw-r--r-- | tools/testing/selftests/kvm/x86/pmu_event_filter_test.c | 4 |
5 files changed, 77 insertions, 3 deletions
diff --git a/tools/testing/selftests/kvm/include/x86/pmu.h b/tools/testing/selftests/kvm/include/x86/pmu.h index 2aabda2da002..72575eadb63a 100644 --- a/tools/testing/selftests/kvm/include/x86/pmu.h +++ b/tools/testing/selftests/kvm/include/x86/pmu.h @@ -5,8 +5,11 @@ #ifndef SELFTEST_KVM_PMU_H #define SELFTEST_KVM_PMU_H +#include <stdbool.h> #include <stdint.h> +#include <linux/bits.h> + #define KVM_PMU_EVENT_FILTER_MAX_EVENTS 300 /* @@ -104,4 +107,17 @@ enum amd_pmu_zen_events { extern const uint64_t intel_pmu_arch_events[]; extern const uint64_t amd_pmu_zen_events[]; +enum pmu_errata { + INSTRUCTIONS_RETIRED_OVERCOUNT, + BRANCHES_RETIRED_OVERCOUNT, +}; +extern uint64_t pmu_errata_mask; + +void kvm_init_pmu_errata(void); + +static inline bool this_pmu_has_errata(enum pmu_errata errata) +{ + return pmu_errata_mask & BIT_ULL(errata); +} + #endif /* SELFTEST_KVM_PMU_H */ diff --git a/tools/testing/selftests/kvm/lib/x86/pmu.c b/tools/testing/selftests/kvm/lib/x86/pmu.c index 5ab44bf54773..34cb57d1d671 100644 --- a/tools/testing/selftests/kvm/lib/x86/pmu.c +++ b/tools/testing/selftests/kvm/lib/x86/pmu.c @@ -8,6 +8,7 @@ #include <linux/kernel.h> #include "kvm_util.h" +#include "processor.h" #include "pmu.h" const uint64_t intel_pmu_arch_events[] = { @@ -34,3 +35,46 @@ const uint64_t amd_pmu_zen_events[] = { AMD_ZEN_BRANCHES_MISPREDICTED, }; kvm_static_assert(ARRAY_SIZE(amd_pmu_zen_events) == NR_AMD_ZEN_EVENTS); + +/* + * For Intel Atom CPUs, the PMU events "Instruction Retired" or + * "Branch Instruction Retired" may be overcounted for some certain + * instructions, like FAR CALL/JMP, RETF, IRET, VMENTRY/VMEXIT/VMPTRLD + * and complex SGX/SMX/CSTATE instructions/flows. + * + * The detailed information can be found in the errata (section SRF7): + * https://edc.intel.com/content/www/us/en/design/products-and-solutions/processors-and-chipsets/sierra-forest/xeon-6700-series-processor-with-e-cores-specification-update/errata-details/ + * + * For the Atom platforms before Sierra Forest (including Sierra Forest), + * Both 2 events "Instruction Retired" and "Branch Instruction Retired" would + * be overcounted on these certain instructions, but for Clearwater Forest + * only "Instruction Retired" event is overcounted on these instructions. + */ +static uint64_t get_pmu_errata(void) +{ + if (!this_cpu_is_intel()) + return 0; + + if (this_cpu_family() != 0x6) + return 0; + + switch (this_cpu_model()) { + case 0xDD: /* Clearwater Forest */ + return BIT_ULL(INSTRUCTIONS_RETIRED_OVERCOUNT); + case 0xAF: /* Sierra Forest */ + case 0x4D: /* Avaton, Rangely */ + case 0x5F: /* Denverton */ + case 0x86: /* Jacobsville */ + return BIT_ULL(INSTRUCTIONS_RETIRED_OVERCOUNT) | + BIT_ULL(BRANCHES_RETIRED_OVERCOUNT); + default: + return 0; + } +} + +uint64_t pmu_errata_mask; + +void kvm_init_pmu_errata(void) +{ + pmu_errata_mask = get_pmu_errata(); +} diff --git a/tools/testing/selftests/kvm/lib/x86/processor.c b/tools/testing/selftests/kvm/lib/x86/processor.c index 3b63c99f7b96..4402d2e1ea69 100644 --- a/tools/testing/selftests/kvm/lib/x86/processor.c +++ b/tools/testing/selftests/kvm/lib/x86/processor.c @@ -6,6 +6,7 @@ #include "linux/bitmap.h" #include "test_util.h" #include "kvm_util.h" +#include "pmu.h" #include "processor.h" #include "sev.h" @@ -638,6 +639,7 @@ void kvm_arch_vm_post_create(struct kvm_vm *vm) sync_global_to_guest(vm, host_cpu_is_intel); sync_global_to_guest(vm, host_cpu_is_amd); sync_global_to_guest(vm, is_forced_emulation_enabled); + sync_global_to_guest(vm, pmu_errata_mask); if (is_sev_vm(vm)) { struct kvm_sev_init init = { 0 }; @@ -1269,6 +1271,8 @@ void kvm_selftest_arch_init(void) host_cpu_is_intel = this_cpu_is_intel(); host_cpu_is_amd = this_cpu_is_amd(); is_forced_emulation_enabled = kvm_is_forced_emulation_enabled(); + + kvm_init_pmu_errata(); } bool sys_clocksource_is_based_on_tsc(void) diff --git a/tools/testing/selftests/kvm/x86/pmu_counters_test.c b/tools/testing/selftests/kvm/x86/pmu_counters_test.c index 24599d98f898..eb6c12a2cdd4 100644 --- a/tools/testing/selftests/kvm/x86/pmu_counters_test.c +++ b/tools/testing/selftests/kvm/x86/pmu_counters_test.c @@ -163,10 +163,18 @@ static void guest_assert_event_count(uint8_t idx, uint32_t pmc, uint32_t pmc_msr switch (idx) { case INTEL_ARCH_INSTRUCTIONS_RETIRED_INDEX: - GUEST_ASSERT_EQ(count, NUM_INSNS_RETIRED); + /* Relax precise count check due to VM-EXIT/VM-ENTRY overcount issue */ + if (this_pmu_has_errata(INSTRUCTIONS_RETIRED_OVERCOUNT)) + GUEST_ASSERT(count >= NUM_INSNS_RETIRED); + else + GUEST_ASSERT_EQ(count, NUM_INSNS_RETIRED); break; case INTEL_ARCH_BRANCHES_RETIRED_INDEX: - GUEST_ASSERT_EQ(count, NUM_BRANCH_INSNS_RETIRED); + /* Relax precise count check due to VM-EXIT/VM-ENTRY overcount issue */ + if (this_pmu_has_errata(BRANCHES_RETIRED_OVERCOUNT)) + GUEST_ASSERT(count >= NUM_BRANCH_INSNS_RETIRED); + else + GUEST_ASSERT_EQ(count, NUM_BRANCH_INSNS_RETIRED); break; case INTEL_ARCH_LLC_REFERENCES_INDEX: case INTEL_ARCH_LLC_MISSES_INDEX: diff --git a/tools/testing/selftests/kvm/x86/pmu_event_filter_test.c b/tools/testing/selftests/kvm/x86/pmu_event_filter_test.c index c15513cd74d1..1c5b7611db24 100644 --- a/tools/testing/selftests/kvm/x86/pmu_event_filter_test.c +++ b/tools/testing/selftests/kvm/x86/pmu_event_filter_test.c @@ -214,8 +214,10 @@ static void remove_event(struct __kvm_pmu_event_filter *f, uint64_t event) do { \ uint64_t br = pmc_results.branches_retired; \ uint64_t ir = pmc_results.instructions_retired; \ + bool br_matched = this_pmu_has_errata(BRANCHES_RETIRED_OVERCOUNT) ? \ + br >= NUM_BRANCHES : br == NUM_BRANCHES; \ \ - if (br && br != NUM_BRANCHES) \ + if (br && !br_matched) \ pr_info("%s: Branch instructions retired = %lu (expected %u)\n", \ __func__, br, NUM_BRANCHES); \ TEST_ASSERT(br, "%s: Branch instructions retired = %lu (expected > 0)", \ |