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Diffstat (limited to '')
| -rw-r--r-- | tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c | 910 |
1 files changed, 910 insertions, 0 deletions
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 new file mode 100644 index 000000000000..3c85d1ae9893 --- /dev/null +++ b/tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c @@ -0,0 +1,910 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Test for x86 KVM_SET_PMU_EVENT_FILTER. + * + * Copyright (C) 2022, Google LLC. + * + * This work is licensed under the terms of the GNU GPL, version 2. + * + * Verifies the expected behavior of allow lists and deny lists for + * virtual PMU events. + */ + +#define _GNU_SOURCE /* for program_invocation_short_name */ + +#include "kvm_util.h" +#include "pmu.h" +#include "processor.h" +#include "test_util.h" + +#define NUM_BRANCHES 42 +#define MAX_TEST_EVENTS 10 + +#define PMU_EVENT_FILTER_INVALID_ACTION (KVM_PMU_EVENT_DENY + 1) +#define PMU_EVENT_FILTER_INVALID_FLAGS (KVM_PMU_EVENT_FLAGS_VALID_MASK << 1) +#define PMU_EVENT_FILTER_INVALID_NEVENTS (KVM_PMU_EVENT_FILTER_MAX_EVENTS + 1) + +struct __kvm_pmu_event_filter { + __u32 action; + __u32 nevents; + __u32 fixed_counter_bitmap; + __u32 flags; + __u32 pad[4]; + __u64 events[KVM_PMU_EVENT_FILTER_MAX_EVENTS]; +}; + +/* + * This event list comprises Intel's known architectural events, plus AMD's + * "retired branch instructions" for Zen1-Zen3 (and* possibly other AMD CPUs). + * Note, AMD and Intel use the same encoding for instructions retired. + */ +kvm_static_assert(INTEL_ARCH_INSTRUCTIONS_RETIRED == AMD_ZEN_INSTRUCTIONS_RETIRED); + +static const struct __kvm_pmu_event_filter base_event_filter = { + .nevents = ARRAY_SIZE(base_event_filter.events), + .events = { + INTEL_ARCH_CPU_CYCLES, + INTEL_ARCH_INSTRUCTIONS_RETIRED, + INTEL_ARCH_REFERENCE_CYCLES, + INTEL_ARCH_LLC_REFERENCES, + INTEL_ARCH_LLC_MISSES, + INTEL_ARCH_BRANCHES_RETIRED, + INTEL_ARCH_BRANCHES_MISPREDICTED, + INTEL_ARCH_TOPDOWN_SLOTS, + AMD_ZEN_BRANCHES_RETIRED, + }, +}; + +struct { + uint64_t loads; + uint64_t stores; + uint64_t loads_stores; + uint64_t branches_retired; + uint64_t instructions_retired; +} pmc_results; + +/* + * If we encounter a #GP during the guest PMU sanity check, then the guest + * PMU is not functional. Inform the hypervisor via GUEST_SYNC(0). + */ +static void guest_gp_handler(struct ex_regs *regs) +{ + GUEST_SYNC(-EFAULT); +} + +/* + * Check that we can write a new value to the given MSR and read it back. + * The caller should provide a non-empty set of bits that are safe to flip. + * + * Return on success. GUEST_SYNC(0) on error. + */ +static void check_msr(uint32_t msr, uint64_t bits_to_flip) +{ + uint64_t v = rdmsr(msr) ^ bits_to_flip; + + wrmsr(msr, v); + if (rdmsr(msr) != v) + GUEST_SYNC(-EIO); + + v ^= bits_to_flip; + wrmsr(msr, v); + if (rdmsr(msr) != v) + GUEST_SYNC(-EIO); +} + +static void run_and_measure_loop(uint32_t msr_base) +{ + const uint64_t branches_retired = rdmsr(msr_base + 0); + const uint64_t insn_retired = rdmsr(msr_base + 1); + + __asm__ __volatile__("loop ." : "+c"((int){NUM_BRANCHES})); + + pmc_results.branches_retired = rdmsr(msr_base + 0) - branches_retired; + pmc_results.instructions_retired = rdmsr(msr_base + 1) - insn_retired; +} + +static void intel_guest_code(void) +{ + check_msr(MSR_CORE_PERF_GLOBAL_CTRL, 1); + check_msr(MSR_P6_EVNTSEL0, 0xffff); + check_msr(MSR_IA32_PMC0, 0xffff); + GUEST_SYNC(0); + + for (;;) { + wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, 0); + wrmsr(MSR_P6_EVNTSEL0, ARCH_PERFMON_EVENTSEL_ENABLE | + ARCH_PERFMON_EVENTSEL_OS | INTEL_ARCH_BRANCHES_RETIRED); + wrmsr(MSR_P6_EVNTSEL1, ARCH_PERFMON_EVENTSEL_ENABLE | + ARCH_PERFMON_EVENTSEL_OS | INTEL_ARCH_INSTRUCTIONS_RETIRED); + wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, 0x3); + + run_and_measure_loop(MSR_IA32_PMC0); + GUEST_SYNC(0); + } +} + +/* + * To avoid needing a check for CPUID.80000001:ECX.PerfCtrExtCore[bit 23], + * this code uses the always-available, legacy K7 PMU MSRs, which alias to + * the first four of the six extended core PMU MSRs. + */ +static void amd_guest_code(void) +{ + check_msr(MSR_K7_EVNTSEL0, 0xffff); + check_msr(MSR_K7_PERFCTR0, 0xffff); + GUEST_SYNC(0); + + for (;;) { + wrmsr(MSR_K7_EVNTSEL0, 0); + wrmsr(MSR_K7_EVNTSEL0, ARCH_PERFMON_EVENTSEL_ENABLE | + ARCH_PERFMON_EVENTSEL_OS | AMD_ZEN_BRANCHES_RETIRED); + wrmsr(MSR_K7_EVNTSEL1, ARCH_PERFMON_EVENTSEL_ENABLE | + ARCH_PERFMON_EVENTSEL_OS | AMD_ZEN_INSTRUCTIONS_RETIRED); + + run_and_measure_loop(MSR_K7_PERFCTR0); + GUEST_SYNC(0); + } +} + +/* + * Run the VM to the next GUEST_SYNC(value), and return the value passed + * to the sync. Any other exit from the guest is fatal. + */ +static uint64_t run_vcpu_to_sync(struct kvm_vcpu *vcpu) +{ + struct ucall uc; + + vcpu_run(vcpu); + TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO); + get_ucall(vcpu, &uc); + TEST_ASSERT(uc.cmd == UCALL_SYNC, + "Received ucall other than UCALL_SYNC: %lu", uc.cmd); + return uc.args[1]; +} + +static void run_vcpu_and_sync_pmc_results(struct kvm_vcpu *vcpu) +{ + uint64_t r; + + memset(&pmc_results, 0, sizeof(pmc_results)); + sync_global_to_guest(vcpu->vm, pmc_results); + + r = run_vcpu_to_sync(vcpu); + TEST_ASSERT(!r, "Unexpected sync value: 0x%lx", r); + + sync_global_from_guest(vcpu->vm, pmc_results); +} + +/* + * In a nested environment or if the vPMU is disabled, the guest PMU + * might not work as architected (accessing the PMU MSRs may raise + * #GP, or writes could simply be discarded). In those situations, + * there is no point in running these tests. The guest code will perform + * a sanity check and then GUEST_SYNC(success). In the case of failure, + * the behavior of the guest on resumption is undefined. + */ +static bool sanity_check_pmu(struct kvm_vcpu *vcpu) +{ + uint64_t r; + + vm_install_exception_handler(vcpu->vm, GP_VECTOR, guest_gp_handler); + r = run_vcpu_to_sync(vcpu); + vm_install_exception_handler(vcpu->vm, GP_VECTOR, NULL); + + return !r; +} + +/* + * Remove the first occurrence of 'event' (if any) from the filter's + * event list. + */ +static void remove_event(struct __kvm_pmu_event_filter *f, uint64_t event) +{ + bool found = false; + int i; + + for (i = 0; i < f->nevents; i++) { + if (found) + f->events[i - 1] = f->events[i]; + else + found = f->events[i] == event; + } + if (found) + f->nevents--; +} + +#define ASSERT_PMC_COUNTING_INSTRUCTIONS() \ +do { \ + uint64_t br = pmc_results.branches_retired; \ + uint64_t ir = pmc_results.instructions_retired; \ + \ + if (br && br != NUM_BRANCHES) \ + pr_info("%s: Branch instructions retired = %lu (expected %u)\n", \ + __func__, br, NUM_BRANCHES); \ + TEST_ASSERT(br, "%s: Branch instructions retired = %lu (expected > 0)", \ + __func__, br); \ + TEST_ASSERT(ir, "%s: Instructions retired = %lu (expected > 0)", \ + __func__, ir); \ +} while (0) + +#define ASSERT_PMC_NOT_COUNTING_INSTRUCTIONS() \ +do { \ + uint64_t br = pmc_results.branches_retired; \ + uint64_t ir = pmc_results.instructions_retired; \ + \ + TEST_ASSERT(!br, "%s: Branch instructions retired = %lu (expected 0)", \ + __func__, br); \ + TEST_ASSERT(!ir, "%s: Instructions retired = %lu (expected 0)", \ + __func__, ir); \ +} while (0) + +static void test_without_filter(struct kvm_vcpu *vcpu) +{ + run_vcpu_and_sync_pmc_results(vcpu); + + ASSERT_PMC_COUNTING_INSTRUCTIONS(); +} + +static void test_with_filter(struct kvm_vcpu *vcpu, + struct __kvm_pmu_event_filter *__f) +{ + struct kvm_pmu_event_filter *f = (void *)__f; + + vm_ioctl(vcpu->vm, KVM_SET_PMU_EVENT_FILTER, f); + run_vcpu_and_sync_pmc_results(vcpu); +} + +static void test_amd_deny_list(struct kvm_vcpu *vcpu) +{ + struct __kvm_pmu_event_filter f = { + .action = KVM_PMU_EVENT_DENY, + .nevents = 1, + .events = { + RAW_EVENT(0x1C2, 0), + }, + }; + + test_with_filter(vcpu, &f); + + ASSERT_PMC_COUNTING_INSTRUCTIONS(); +} + +static void test_member_deny_list(struct kvm_vcpu *vcpu) +{ + struct __kvm_pmu_event_filter f = base_event_filter; + + f.action = KVM_PMU_EVENT_DENY; + test_with_filter(vcpu, &f); + + ASSERT_PMC_NOT_COUNTING_INSTRUCTIONS(); +} + +static void test_member_allow_list(struct kvm_vcpu *vcpu) +{ + struct __kvm_pmu_event_filter f = base_event_filter; + + f.action = KVM_PMU_EVENT_ALLOW; + test_with_filter(vcpu, &f); + + ASSERT_PMC_COUNTING_INSTRUCTIONS(); +} + +static void test_not_member_deny_list(struct kvm_vcpu *vcpu) +{ + struct __kvm_pmu_event_filter f = base_event_filter; + + f.action = KVM_PMU_EVENT_DENY; + + remove_event(&f, INTEL_ARCH_INSTRUCTIONS_RETIRED); + remove_event(&f, INTEL_ARCH_BRANCHES_RETIRED); + remove_event(&f, AMD_ZEN_BRANCHES_RETIRED); + test_with_filter(vcpu, &f); + + ASSERT_PMC_COUNTING_INSTRUCTIONS(); +} + +static void test_not_member_allow_list(struct kvm_vcpu *vcpu) +{ + struct __kvm_pmu_event_filter f = base_event_filter; + + f.action = KVM_PMU_EVENT_ALLOW; + + remove_event(&f, INTEL_ARCH_INSTRUCTIONS_RETIRED); + remove_event(&f, INTEL_ARCH_BRANCHES_RETIRED); + remove_event(&f, AMD_ZEN_BRANCHES_RETIRED); + test_with_filter(vcpu, &f); + + ASSERT_PMC_NOT_COUNTING_INSTRUCTIONS(); +} + +/* + * Verify that setting KVM_PMU_CAP_DISABLE prevents the use of the PMU. + * + * Note that KVM_CAP_PMU_CAPABILITY must be invoked prior to creating VCPUs. + */ +static void test_pmu_config_disable(void (*guest_code)(void)) +{ + struct kvm_vcpu *vcpu; + int r; + struct kvm_vm *vm; + + r = kvm_check_cap(KVM_CAP_PMU_CAPABILITY); + if (!(r & KVM_PMU_CAP_DISABLE)) + return; + + vm = vm_create(1); + + vm_enable_cap(vm, KVM_CAP_PMU_CAPABILITY, KVM_PMU_CAP_DISABLE); + + vcpu = vm_vcpu_add(vm, 0, guest_code); + vm_init_descriptor_tables(vm); + vcpu_init_descriptor_tables(vcpu); + + TEST_ASSERT(!sanity_check_pmu(vcpu), + "Guest should not be able to use disabled PMU."); + + kvm_vm_free(vm); +} + +/* + * On Intel, check for a non-zero PMU version, at least one general-purpose + * counter per logical processor, and support for counting the number of branch + * instructions retired. + */ +static bool use_intel_pmu(void) +{ + return host_cpu_is_intel && + kvm_cpu_property(X86_PROPERTY_PMU_VERSION) && + kvm_cpu_property(X86_PROPERTY_PMU_NR_GP_COUNTERS) && + kvm_pmu_has(X86_PMU_FEATURE_BRANCH_INSNS_RETIRED); +} + +static bool is_zen1(uint32_t family, uint32_t model) +{ + return family == 0x17 && model <= 0x0f; +} + +static bool is_zen2(uint32_t family, uint32_t model) +{ + return family == 0x17 && model >= 0x30 && model <= 0x3f; +} + +static bool is_zen3(uint32_t family, uint32_t model) +{ + return family == 0x19 && model <= 0x0f; +} + +/* + * Determining AMD support for a PMU event requires consulting the AMD + * PPR for the CPU or reference material derived therefrom. The AMD + * test code herein has been verified to work on Zen1, Zen2, and Zen3. + * + * Feel free to add more AMD CPUs that are documented to support event + * select 0xc2 umask 0 as "retired branch instructions." + */ +static bool use_amd_pmu(void) +{ + uint32_t family = kvm_cpu_family(); + uint32_t model = kvm_cpu_model(); + + return host_cpu_is_amd && + (is_zen1(family, model) || + is_zen2(family, model) || + is_zen3(family, model)); +} + +/* + * "MEM_INST_RETIRED.ALL_LOADS", "MEM_INST_RETIRED.ALL_STORES", and + * "MEM_INST_RETIRED.ANY" from https://perfmon-events.intel.com/ + * supported on Intel Xeon processors: + * - Sapphire Rapids, Ice Lake, Cascade Lake, Skylake. + */ +#define MEM_INST_RETIRED 0xD0 +#define MEM_INST_RETIRED_LOAD RAW_EVENT(MEM_INST_RETIRED, 0x81) +#define MEM_INST_RETIRED_STORE RAW_EVENT(MEM_INST_RETIRED, 0x82) +#define MEM_INST_RETIRED_LOAD_STORE RAW_EVENT(MEM_INST_RETIRED, 0x83) + +static bool supports_event_mem_inst_retired(void) +{ + uint32_t eax, ebx, ecx, edx; + + cpuid(1, &eax, &ebx, &ecx, &edx); + if (x86_family(eax) == 0x6) { + switch (x86_model(eax)) { + /* Sapphire Rapids */ + case 0x8F: + /* Ice Lake */ + case 0x6A: + /* Skylake */ + /* Cascade Lake */ + case 0x55: + return true; + } + } + + return false; +} + +/* + * "LS Dispatch", from Processor Programming Reference + * (PPR) for AMD Family 17h Model 01h, Revision B1 Processors, + * Preliminary Processor Programming Reference (PPR) for AMD Family + * 17h Model 31h, Revision B0 Processors, and Preliminary Processor + * Programming Reference (PPR) for AMD Family 19h Model 01h, Revision + * B1 Processors Volume 1 of 2. + */ +#define LS_DISPATCH 0x29 +#define LS_DISPATCH_LOAD RAW_EVENT(LS_DISPATCH, BIT(0)) +#define LS_DISPATCH_STORE RAW_EVENT(LS_DISPATCH, BIT(1)) +#define LS_DISPATCH_LOAD_STORE RAW_EVENT(LS_DISPATCH, BIT(2)) + +#define INCLUDE_MASKED_ENTRY(event_select, mask, match) \ + KVM_PMU_ENCODE_MASKED_ENTRY(event_select, mask, match, false) +#define EXCLUDE_MASKED_ENTRY(event_select, mask, match) \ + KVM_PMU_ENCODE_MASKED_ENTRY(event_select, mask, match, true) + +static void masked_events_guest_test(uint32_t msr_base) +{ + /* + * The actual value of the counters don't determine the outcome of + * the test. Only that they are zero or non-zero. + */ + const uint64_t loads = rdmsr(msr_base + 0); + const uint64_t stores = rdmsr(msr_base + 1); + const uint64_t loads_stores = rdmsr(msr_base + 2); + int val; + + + __asm__ __volatile__("movl $0, %[v];" + "movl %[v], %%eax;" + "incl %[v];" + : [v]"+m"(val) :: "eax"); + + pmc_results.loads = rdmsr(msr_base + 0) - loads; + pmc_results.stores = rdmsr(msr_base + 1) - stores; + pmc_results.loads_stores = rdmsr(msr_base + 2) - loads_stores; +} + +static void intel_masked_events_guest_code(void) +{ + for (;;) { + wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, 0); + + wrmsr(MSR_P6_EVNTSEL0 + 0, ARCH_PERFMON_EVENTSEL_ENABLE | + ARCH_PERFMON_EVENTSEL_OS | MEM_INST_RETIRED_LOAD); + wrmsr(MSR_P6_EVNTSEL0 + 1, ARCH_PERFMON_EVENTSEL_ENABLE | + ARCH_PERFMON_EVENTSEL_OS | MEM_INST_RETIRED_STORE); + wrmsr(MSR_P6_EVNTSEL0 + 2, ARCH_PERFMON_EVENTSEL_ENABLE | + ARCH_PERFMON_EVENTSEL_OS | MEM_INST_RETIRED_LOAD_STORE); + + wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, 0x7); + + masked_events_guest_test(MSR_IA32_PMC0); + GUEST_SYNC(0); + } +} + +static void amd_masked_events_guest_code(void) +{ + for (;;) { + wrmsr(MSR_K7_EVNTSEL0, 0); + wrmsr(MSR_K7_EVNTSEL1, 0); + wrmsr(MSR_K7_EVNTSEL2, 0); + + wrmsr(MSR_K7_EVNTSEL0, ARCH_PERFMON_EVENTSEL_ENABLE | + ARCH_PERFMON_EVENTSEL_OS | LS_DISPATCH_LOAD); + wrmsr(MSR_K7_EVNTSEL1, ARCH_PERFMON_EVENTSEL_ENABLE | + ARCH_PERFMON_EVENTSEL_OS | LS_DISPATCH_STORE); + wrmsr(MSR_K7_EVNTSEL2, ARCH_PERFMON_EVENTSEL_ENABLE | + ARCH_PERFMON_EVENTSEL_OS | LS_DISPATCH_LOAD_STORE); + + masked_events_guest_test(MSR_K7_PERFCTR0); + GUEST_SYNC(0); + } +} + +static void run_masked_events_test(struct kvm_vcpu *vcpu, + const uint64_t masked_events[], + const int nmasked_events) +{ + struct __kvm_pmu_event_filter f = { + .nevents = nmasked_events, + .action = KVM_PMU_EVENT_ALLOW, + .flags = KVM_PMU_EVENT_FLAG_MASKED_EVENTS, + }; + + memcpy(f.events, masked_events, sizeof(uint64_t) * nmasked_events); + test_with_filter(vcpu, &f); +} + +#define ALLOW_LOADS BIT(0) +#define ALLOW_STORES BIT(1) +#define ALLOW_LOADS_STORES BIT(2) + +struct masked_events_test { + uint64_t intel_events[MAX_TEST_EVENTS]; + uint64_t intel_event_end; + uint64_t amd_events[MAX_TEST_EVENTS]; + uint64_t amd_event_end; + const char *msg; + uint32_t flags; +}; + +/* + * These are the test cases for the masked events tests. + * + * For each test, the guest enables 3 PMU counters (loads, stores, + * loads + stores). The filter is then set in KVM with the masked events + * provided. The test then verifies that the counters agree with which + * ones should be counting and which ones should be filtered. + */ +const struct masked_events_test test_cases[] = { + { + .intel_events = { + INCLUDE_MASKED_ENTRY(MEM_INST_RETIRED, 0xFF, 0x81), + }, + .amd_events = { + INCLUDE_MASKED_ENTRY(LS_DISPATCH, 0xFF, BIT(0)), + }, + .msg = "Only allow loads.", + .flags = ALLOW_LOADS, + }, { + .intel_events = { + INCLUDE_MASKED_ENTRY(MEM_INST_RETIRED, 0xFF, 0x82), + }, + .amd_events = { + INCLUDE_MASKED_ENTRY(LS_DISPATCH, 0xFF, BIT(1)), + }, + .msg = "Only allow stores.", + .flags = ALLOW_STORES, + }, { + .intel_events = { + INCLUDE_MASKED_ENTRY(MEM_INST_RETIRED, 0xFF, 0x83), + }, + .amd_events = { + INCLUDE_MASKED_ENTRY(LS_DISPATCH, 0xFF, BIT(2)), + }, + .msg = "Only allow loads + stores.", + .flags = ALLOW_LOADS_STORES, + }, { + .intel_events = { + INCLUDE_MASKED_ENTRY(MEM_INST_RETIRED, 0x7C, 0), + EXCLUDE_MASKED_ENTRY(MEM_INST_RETIRED, 0xFF, 0x83), + }, + .amd_events = { + INCLUDE_MASKED_ENTRY(LS_DISPATCH, ~(BIT(0) | BIT(1)), 0), + }, + .msg = "Only allow loads and stores.", + .flags = ALLOW_LOADS | ALLOW_STORES, + }, { + .intel_events = { + INCLUDE_MASKED_ENTRY(MEM_INST_RETIRED, 0x7C, 0), + EXCLUDE_MASKED_ENTRY(MEM_INST_RETIRED, 0xFF, 0x82), + }, + .amd_events = { + INCLUDE_MASKED_ENTRY(LS_DISPATCH, 0xF8, 0), + EXCLUDE_MASKED_ENTRY(LS_DISPATCH, 0xFF, BIT(1)), + }, + .msg = "Only allow loads and loads + stores.", + .flags = ALLOW_LOADS | ALLOW_LOADS_STORES + }, { + .intel_events = { + INCLUDE_MASKED_ENTRY(MEM_INST_RETIRED, 0xFE, 0x82), + }, + .amd_events = { + INCLUDE_MASKED_ENTRY(LS_DISPATCH, 0xF8, 0), + EXCLUDE_MASKED_ENTRY(LS_DISPATCH, 0xFF, BIT(0)), + }, + .msg = "Only allow stores and loads + stores.", + .flags = ALLOW_STORES | ALLOW_LOADS_STORES + }, { + .intel_events = { + INCLUDE_MASKED_ENTRY(MEM_INST_RETIRED, 0x7C, 0), + }, + .amd_events = { + INCLUDE_MASKED_ENTRY(LS_DISPATCH, 0xF8, 0), + }, + .msg = "Only allow loads, stores, and loads + stores.", + .flags = ALLOW_LOADS | ALLOW_STORES | ALLOW_LOADS_STORES + }, +}; + +static int append_test_events(const struct masked_events_test *test, + uint64_t *events, int nevents) +{ + const uint64_t *evts; + int i; + + evts = use_intel_pmu() ? test->intel_events : test->amd_events; + for (i = 0; i < MAX_TEST_EVENTS; i++) { + if (evts[i] == 0) + break; + + events[nevents + i] = evts[i]; + } + + return nevents + i; +} + +static bool bool_eq(bool a, bool b) +{ + return a == b; +} + +static void run_masked_events_tests(struct kvm_vcpu *vcpu, uint64_t *events, + int nevents) +{ + int ntests = ARRAY_SIZE(test_cases); + int i, n; + + for (i = 0; i < ntests; i++) { + const struct masked_events_test *test = &test_cases[i]; + + /* Do any test case events overflow MAX_TEST_EVENTS? */ + assert(test->intel_event_end == 0); + assert(test->amd_event_end == 0); + + n = append_test_events(test, events, nevents); + + run_masked_events_test(vcpu, events, n); + + TEST_ASSERT(bool_eq(pmc_results.loads, test->flags & ALLOW_LOADS) && + bool_eq(pmc_results.stores, test->flags & ALLOW_STORES) && + bool_eq(pmc_results.loads_stores, + test->flags & ALLOW_LOADS_STORES), + "%s loads: %lu, stores: %lu, loads + stores: %lu", + test->msg, pmc_results.loads, pmc_results.stores, + pmc_results.loads_stores); + } +} + +static void add_dummy_events(uint64_t *events, int nevents) +{ + int i; + + for (i = 0; i < nevents; i++) { + int event_select = i % 0xFF; + bool exclude = ((i % 4) == 0); + + if (event_select == MEM_INST_RETIRED || + event_select == LS_DISPATCH) + event_select++; + + events[i] = KVM_PMU_ENCODE_MASKED_ENTRY(event_select, 0, + 0, exclude); + } +} + +static void test_masked_events(struct kvm_vcpu *vcpu) +{ + int nevents = KVM_PMU_EVENT_FILTER_MAX_EVENTS - MAX_TEST_EVENTS; + uint64_t events[KVM_PMU_EVENT_FILTER_MAX_EVENTS]; + + /* Run the test cases against a sparse PMU event filter. */ + run_masked_events_tests(vcpu, events, 0); + + /* Run the test cases against a dense PMU event filter. */ + add_dummy_events(events, KVM_PMU_EVENT_FILTER_MAX_EVENTS); + run_masked_events_tests(vcpu, events, nevents); +} + +static int set_pmu_event_filter(struct kvm_vcpu *vcpu, + struct __kvm_pmu_event_filter *__f) +{ + struct kvm_pmu_event_filter *f = (void *)__f; + + return __vm_ioctl(vcpu->vm, KVM_SET_PMU_EVENT_FILTER, f); +} + +static int set_pmu_single_event_filter(struct kvm_vcpu *vcpu, uint64_t event, + uint32_t flags, uint32_t action) +{ + struct __kvm_pmu_event_filter f = { + .nevents = 1, + .flags = flags, + .action = action, + .events = { + event, + }, + }; + + return set_pmu_event_filter(vcpu, &f); +} + +static void test_filter_ioctl(struct kvm_vcpu *vcpu) +{ + uint8_t nr_fixed_counters = kvm_cpu_property(X86_PROPERTY_PMU_NR_FIXED_COUNTERS); + struct __kvm_pmu_event_filter f; + uint64_t e = ~0ul; + int r; + + /* + * Unfortunately having invalid bits set in event data is expected to + * pass when flags == 0 (bits other than eventsel+umask). + */ + r = set_pmu_single_event_filter(vcpu, e, 0, KVM_PMU_EVENT_ALLOW); + TEST_ASSERT(r == 0, "Valid PMU Event Filter is failing"); + + r = set_pmu_single_event_filter(vcpu, e, + KVM_PMU_EVENT_FLAG_MASKED_EVENTS, + KVM_PMU_EVENT_ALLOW); + TEST_ASSERT(r != 0, "Invalid PMU Event Filter is expected to fail"); + + e = KVM_PMU_ENCODE_MASKED_ENTRY(0xff, 0xff, 0xff, 0xf); + r = set_pmu_single_event_filter(vcpu, e, + KVM_PMU_EVENT_FLAG_MASKED_EVENTS, + KVM_PMU_EVENT_ALLOW); + TEST_ASSERT(r == 0, "Valid PMU Event Filter is failing"); + + f = base_event_filter; + f.action = PMU_EVENT_FILTER_INVALID_ACTION; + r = set_pmu_event_filter(vcpu, &f); + TEST_ASSERT(r, "Set invalid action is expected to fail"); + + f = base_event_filter; + f.flags = PMU_EVENT_FILTER_INVALID_FLAGS; + r = set_pmu_event_filter(vcpu, &f); + TEST_ASSERT(r, "Set invalid flags is expected to fail"); + + f = base_event_filter; + f.nevents = PMU_EVENT_FILTER_INVALID_NEVENTS; + r = set_pmu_event_filter(vcpu, &f); + TEST_ASSERT(r, "Exceeding the max number of filter events should fail"); + + f = base_event_filter; + f.fixed_counter_bitmap = ~GENMASK_ULL(nr_fixed_counters, 0); + r = set_pmu_event_filter(vcpu, &f); + TEST_ASSERT(!r, "Masking non-existent fixed counters should be allowed"); +} + +static void intel_run_fixed_counter_guest_code(uint8_t idx) +{ + for (;;) { + wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, 0); + wrmsr(MSR_CORE_PERF_FIXED_CTR0 + idx, 0); + + /* Only OS_EN bit is enabled for fixed counter[idx]. */ + wrmsr(MSR_CORE_PERF_FIXED_CTR_CTRL, FIXED_PMC_CTRL(idx, FIXED_PMC_KERNEL)); + wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, FIXED_PMC_GLOBAL_CTRL_ENABLE(idx)); + __asm__ __volatile__("loop ." : "+c"((int){NUM_BRANCHES})); + wrmsr(MSR_CORE_PERF_GLOBAL_CTRL, 0); + + GUEST_SYNC(rdmsr(MSR_CORE_PERF_FIXED_CTR0 + 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 uint64_t test_set_gp_and_fixed_event_filter(struct kvm_vcpu *vcpu, + uint32_t action, + uint32_t bitmap) +{ + struct __kvm_pmu_event_filter f = base_event_filter; + + f.action = action; + f.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", 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))); + + /* + * Check that fixed_counter_bitmap has higher priority than + * events[] when both are set. + */ + count = test_set_gp_and_fixed_event_filter(vcpu, + KVM_PMU_EVENT_ALLOW, + bitmap); + TEST_ASSERT_EQ(!!count, !!(bitmap & BIT(idx))); + + count = test_set_gp_and_fixed_event_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); + struct kvm_vcpu *vcpu, *vcpu2 = NULL; + struct kvm_vm *vm; + + TEST_REQUIRE(kvm_is_pmu_enabled()); + TEST_REQUIRE(kvm_has_cap(KVM_CAP_PMU_EVENT_FILTER)); + TEST_REQUIRE(kvm_has_cap(KVM_CAP_PMU_EVENT_MASKED_EVENTS)); + + TEST_REQUIRE(use_intel_pmu() || use_amd_pmu()); + guest_code = use_intel_pmu() ? intel_guest_code : amd_guest_code; + + vm = vm_create_with_one_vcpu(&vcpu, guest_code); + + vm_init_descriptor_tables(vm); + vcpu_init_descriptor_tables(vcpu); + + TEST_REQUIRE(sanity_check_pmu(vcpu)); + + if (use_amd_pmu()) + test_amd_deny_list(vcpu); + + test_without_filter(vcpu); + test_member_deny_list(vcpu); + test_member_allow_list(vcpu); + test_not_member_deny_list(vcpu); + test_not_member_allow_list(vcpu); + + if (use_intel_pmu() && + supports_event_mem_inst_retired() && + kvm_cpu_property(X86_PROPERTY_PMU_NR_GP_COUNTERS) >= 3) + vcpu2 = vm_vcpu_add(vm, 2, intel_masked_events_guest_code); + else if (use_amd_pmu()) + vcpu2 = vm_vcpu_add(vm, 2, amd_masked_events_guest_code); + + if (vcpu2) + test_masked_events(vcpu2); + test_filter_ioctl(vcpu); + + kvm_vm_free(vm); + + test_pmu_config_disable(guest_code); + test_fixed_counter_bitmap(); + + return 0; +} |