From d4e36166820a089f6300dc59dbb641e8c150bec1 Mon Sep 17 00:00:00 2001 From: Jinrong Liang Date: Thu, 10 Aug 2023 17:09:44 +0800 Subject: [PATCH] KVM: selftests: Test if event filter meets expectations on fixed counters Add tests to cover that pmu event_filter works as expected when it's applied to fixed performance counters, even if there is none fixed counter exists (e.g. Intel guest pmu version=1 or AMD guest). Signed-off-by: Jinrong Liang Reviewed-by: Isaku Yamahata Link: https://lore.kernel.org/r/20230810090945.16053-6-cloudliang@tencent.com Signed-off-by: Sean Christopherson --- .../selftests/kvm/x86_64/pmu_event_filter_test.c | 80 ++++++++++++++++++++++ 1 file changed, 80 insertions(+) diff --git a/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c b/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c index ca4ff5a..c9355ca 100644 --- a/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c +++ b/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c @@ -27,6 +27,7 @@ #define ARCH_PERFMON_BRANCHES_RETIRED 5 #define NUM_BRANCHES 42 +#define INTEL_PMC_IDX_FIXED 32 /* Matches KVM_PMU_EVENT_FILTER_MAX_EVENTS in pmu.c */ #define MAX_FILTER_EVENTS 300 @@ -808,6 +809,84 @@ static void test_filter_ioctl(struct kvm_vcpu *vcpu) TEST_ASSERT(!r, "Masking non-existent fixed counters should be allowed"); } +static void intel_run_fixed_counter_guest_code(uint8_t fixed_ctr_idx) +{ + for (;;) { + wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, 0); + wrmsr(MSR_CORE_PERF_FIXED_CTR0 + fixed_ctr_idx, 0); + + /* Only OS_EN bit is enabled for fixed counter[idx]. */ + wrmsr(MSR_CORE_PERF_FIXED_CTR_CTRL, BIT_ULL(4 * fixed_ctr_idx)); + wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, + BIT_ULL(INTEL_PMC_IDX_FIXED + fixed_ctr_idx)); + __asm__ __volatile__("loop ." : "+c"((int){NUM_BRANCHES})); + wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, 0); + + GUEST_SYNC(rdmsr(MSR_CORE_PERF_FIXED_CTR0 + fixed_ctr_idx)); + } +} + +static uint64_t test_with_fixed_counter_filter(struct kvm_vcpu *vcpu, + uint32_t action, uint32_t bitmap) +{ + struct __kvm_pmu_event_filter f = { + .action = action, + .fixed_counter_bitmap = bitmap, + }; + set_pmu_event_filter(vcpu, &f); + + return run_vcpu_to_sync(vcpu); +} + +static void __test_fixed_counter_bitmap(struct kvm_vcpu *vcpu, uint8_t idx, + uint8_t nr_fixed_counters) +{ + unsigned int i; + uint32_t bitmap; + uint64_t count; + + TEST_ASSERT(nr_fixed_counters < sizeof(bitmap) * 8, + "Invalid nr_fixed_counters"); + + /* + * Check the fixed performance counter can count normally when KVM + * userspace doesn't set any pmu filter. + */ + count = run_vcpu_to_sync(vcpu); + TEST_ASSERT(count, "Unexpected count value: %ld\n", count); + + for (i = 0; i < BIT(nr_fixed_counters); i++) { + bitmap = BIT(i); + count = test_with_fixed_counter_filter(vcpu, KVM_PMU_EVENT_ALLOW, + bitmap); + TEST_ASSERT_EQ(!!count, !!(bitmap & BIT(idx))); + + count = test_with_fixed_counter_filter(vcpu, KVM_PMU_EVENT_DENY, + bitmap); + TEST_ASSERT_EQ(!!count, !(bitmap & BIT(idx))); + } +} + +static void test_fixed_counter_bitmap(void) +{ + uint8_t nr_fixed_counters = kvm_cpu_property(X86_PROPERTY_PMU_NR_FIXED_COUNTERS); + struct kvm_vm *vm; + struct kvm_vcpu *vcpu; + uint8_t idx; + + /* + * Check that pmu_event_filter works as expected when it's applied to + * fixed performance counters. + */ + for (idx = 0; idx < nr_fixed_counters; idx++) { + vm = vm_create_with_one_vcpu(&vcpu, + intel_run_fixed_counter_guest_code); + vcpu_args_set(vcpu, 1, idx); + __test_fixed_counter_bitmap(vcpu, idx, nr_fixed_counters); + kvm_vm_free(vm); + } +} + int main(int argc, char *argv[]) { void (*guest_code)(void); @@ -851,6 +930,7 @@ int main(int argc, char *argv[]) kvm_vm_free(vm); test_pmu_config_disable(guest_code); + test_fixed_counter_bitmap(); return 0; } -- 2.7.4