This test implements basic sanity test and cycle/instret event counting tests.
Reviewed-by: Anup Patel anup@brainfault.org Reviewed-by: Andrew Jones ajones@ventanamicro.com Signed-off-by: Atish Patra atishp@rivosinc.com --- tools/testing/selftests/kvm/Makefile | 1 + .../selftests/kvm/riscv/sbi_pmu_test.c | 369 ++++++++++++++++++ 2 files changed, 370 insertions(+) create mode 100644 tools/testing/selftests/kvm/riscv/sbi_pmu_test.c
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 741c7dc16afc..1cfcd2797ee4 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -189,6 +189,7 @@ TEST_GEN_PROGS_s390x += rseq_test TEST_GEN_PROGS_s390x += set_memory_region_test TEST_GEN_PROGS_s390x += kvm_binary_stats_test
+TEST_GEN_PROGS_riscv += riscv/sbi_pmu_test TEST_GEN_PROGS_riscv += arch_timer TEST_GEN_PROGS_riscv += demand_paging_test TEST_GEN_PROGS_riscv += dirty_log_test diff --git a/tools/testing/selftests/kvm/riscv/sbi_pmu_test.c b/tools/testing/selftests/kvm/riscv/sbi_pmu_test.c new file mode 100644 index 000000000000..7c81691e39c5 --- /dev/null +++ b/tools/testing/selftests/kvm/riscv/sbi_pmu_test.c @@ -0,0 +1,369 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * sbi_pmu_test.c - Tests the riscv64 SBI PMU functionality. + * + * Copyright (c) 2024, Rivos Inc. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <sys/types.h> +#include "kvm_util.h" +#include "test_util.h" +#include "processor.h" +#include "sbi.h" + +/* Maximum counters(firmware + hardware) */ +#define RISCV_MAX_PMU_COUNTERS 64 +union sbi_pmu_ctr_info ctrinfo_arr[RISCV_MAX_PMU_COUNTERS]; + +/* Cache the available counters in a bitmask */ +static unsigned long counter_mask_available; + +static bool illegal_handler_invoked; + +unsigned long pmu_csr_read_num(int csr_num) +{ +#define switchcase_csr_read(__csr_num, __val) {\ + case __csr_num: \ + __val = csr_read(__csr_num); \ + break; } +#define switchcase_csr_read_2(__csr_num, __val) {\ + switchcase_csr_read(__csr_num + 0, __val) \ + switchcase_csr_read(__csr_num + 1, __val)} +#define switchcase_csr_read_4(__csr_num, __val) {\ + switchcase_csr_read_2(__csr_num + 0, __val) \ + switchcase_csr_read_2(__csr_num + 2, __val)} +#define switchcase_csr_read_8(__csr_num, __val) {\ + switchcase_csr_read_4(__csr_num + 0, __val) \ + switchcase_csr_read_4(__csr_num + 4, __val)} +#define switchcase_csr_read_16(__csr_num, __val) {\ + switchcase_csr_read_8(__csr_num + 0, __val) \ + switchcase_csr_read_8(__csr_num + 8, __val)} +#define switchcase_csr_read_32(__csr_num, __val) {\ + switchcase_csr_read_16(__csr_num + 0, __val) \ + switchcase_csr_read_16(__csr_num + 16, __val)} + + unsigned long ret = 0; + + switch (csr_num) { + switchcase_csr_read_32(CSR_CYCLE, ret) + switchcase_csr_read_32(CSR_CYCLEH, ret) + default : + break; + } + + return ret; +#undef switchcase_csr_read_32 +#undef switchcase_csr_read_16 +#undef switchcase_csr_read_8 +#undef switchcase_csr_read_4 +#undef switchcase_csr_read_2 +#undef switchcase_csr_read +} + +static inline void dummy_func_loop(uint64_t iter) +{ + int i = 0; + + while (i < iter) { + asm volatile("nop"); + i++; + } +} + +static void start_counter(unsigned long counter, unsigned long start_flags, + unsigned long ival) +{ + struct sbiret ret; + + ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_START, counter, 1, start_flags, + ival, 0, 0); + __GUEST_ASSERT(ret.error == 0, "Unable to start counter %ld\n", counter); +} + +/* This should be invoked only for reset counter use case */ +static void stop_reset_counter(unsigned long counter, unsigned long stop_flags) +{ + struct sbiret ret; + + ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP, counter, 1, + stop_flags | SBI_PMU_STOP_FLAG_RESET, 0, 0, 0); + __GUEST_ASSERT(ret.error == SBI_ERR_ALREADY_STOPPED, + "Unable to stop counter %ld\n", counter); +} + +static void stop_counter(unsigned long counter, unsigned long stop_flags) +{ + struct sbiret ret; + + ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP, counter, 1, stop_flags, + 0, 0, 0); + __GUEST_ASSERT(ret.error == 0, "Unable to stop counter %ld error %ld\n", + counter, ret.error); +} + +static void guest_illegal_exception_handler(struct ex_regs *regs) +{ + __GUEST_ASSERT(regs->cause == EXC_INST_ILLEGAL, + "Unexpected exception handler %lx\n", regs->cause); + + illegal_handler_invoked = true; + /* skip the trapping instruction */ + regs->epc += 4; +} + +static unsigned long get_counter_index(unsigned long cbase, unsigned long cmask, + unsigned long cflags, + unsigned long event) +{ + struct sbiret ret; + + ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, cbase, cmask, + cflags, event, 0, 0); + __GUEST_ASSERT(ret.error == 0, "config matching failed %ld\n", ret.error); + GUEST_ASSERT(ret.value < RISCV_MAX_PMU_COUNTERS); + GUEST_ASSERT(BIT(ret.value) & counter_mask_available); + + return ret.value; +} + +static unsigned long get_num_counters(void) +{ + struct sbiret ret; + + ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_NUM_COUNTERS, 0, 0, 0, 0, 0, 0); + + __GUEST_ASSERT(ret.error == 0, "Unable to retrieve number of counters from SBI PMU"); + __GUEST_ASSERT(ret.value < RISCV_MAX_PMU_COUNTERS, + "Invalid number of counters %ld\n", ret.value); + + return ret.value; +} + +static void update_counter_info(int num_counters) +{ + int i = 0; + struct sbiret ret; + + for (i = 0; i < num_counters; i++) { + ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_GET_INFO, i, 0, 0, 0, 0, 0); + + /* There can be gaps in logical counter indicies*/ + if (ret.error) + continue; + GUEST_ASSERT_NE(ret.value, 0); + + ctrinfo_arr[i].value = ret.value; + counter_mask_available |= BIT(i); + } + + GUEST_ASSERT(counter_mask_available > 0); +} + +static unsigned long read_fw_counter(int idx, union sbi_pmu_ctr_info ctrinfo) +{ + struct sbiret ret; + + ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_FW_READ, idx, 0, 0, 0, 0, 0); + GUEST_ASSERT(ret.error == 0); + return ret.value; +} + +static unsigned long read_counter(int idx, union sbi_pmu_ctr_info ctrinfo) +{ + unsigned long counter_val = 0; + + __GUEST_ASSERT(ctrinfo.type < 2, "Invalid counter type %d", ctrinfo.type); + + if (ctrinfo.type == SBI_PMU_CTR_TYPE_HW) + counter_val = pmu_csr_read_num(ctrinfo.csr); + else if (ctrinfo.type == SBI_PMU_CTR_TYPE_FW) + counter_val = read_fw_counter(idx, ctrinfo); + + return counter_val; +} + +static void test_pmu_event(unsigned long event) +{ + unsigned long counter; + unsigned long counter_value_pre, counter_value_post; + unsigned long counter_init_value = 100; + + counter = get_counter_index(0, counter_mask_available, 0, event); + counter_value_pre = read_counter(counter, ctrinfo_arr[counter]); + + /* Do not set the initial value */ + start_counter(counter, 0, 0); + dummy_func_loop(10000); + stop_counter(counter, 0); + + counter_value_post = read_counter(counter, ctrinfo_arr[counter]); + __GUEST_ASSERT(counter_value_post > counter_value_pre, + "Event update verification failed: post [%lx] pre [%lx]\n", + counter_value_post, counter_value_pre); + + /* + * We can't just update the counter without starting it. + * Do start/stop twice to simulate that by first initializing to a very + * high value and a low value after that. + */ + start_counter(counter, SBI_PMU_START_FLAG_SET_INIT_VALUE, ULONG_MAX/2); + stop_counter(counter, 0); + counter_value_pre = read_counter(counter, ctrinfo_arr[counter]); + + start_counter(counter, SBI_PMU_START_FLAG_SET_INIT_VALUE, counter_init_value); + stop_counter(counter, 0); + counter_value_post = read_counter(counter, ctrinfo_arr[counter]); + __GUEST_ASSERT(counter_value_pre > counter_value_post, + "Counter reinitialization verification failed : post [%lx] pre [%lx]\n", + counter_value_post, counter_value_pre); + + /* Now set the initial value and compare */ + start_counter(counter, SBI_PMU_START_FLAG_SET_INIT_VALUE, counter_init_value); + dummy_func_loop(10000); + stop_counter(counter, 0); + + counter_value_post = read_counter(counter, ctrinfo_arr[counter]); + __GUEST_ASSERT(counter_value_post > counter_init_value, + "Event update verification failed: post [%lx] pre [%lx]\n", + counter_value_post, counter_init_value); + + stop_reset_counter(counter, 0); +} + +static void test_invalid_event(void) +{ + struct sbiret ret; + unsigned long event = 0x1234; /* A random event */ + + ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_CFG_MATCH, 0, + counter_mask_available, 0, event, 0, 0); + GUEST_ASSERT_EQ(ret.error, SBI_ERR_NOT_SUPPORTED); +} + +static void test_pmu_events(void) +{ + int num_counters = 0; + + /* Get the counter details */ + num_counters = get_num_counters(); + update_counter_info(num_counters); + + /* Sanity testing for any random invalid event */ + test_invalid_event(); + + /* Only these two events are guaranteed to be present */ + test_pmu_event(SBI_PMU_HW_CPU_CYCLES); + test_pmu_event(SBI_PMU_HW_INSTRUCTIONS); + + GUEST_DONE(); +} + +static void test_pmu_basic_sanity(void) +{ + long out_val = 0; + bool probe; + struct sbiret ret; + int num_counters = 0, i; + union sbi_pmu_ctr_info ctrinfo; + + probe = guest_sbi_probe_extension(SBI_EXT_PMU, &out_val); + GUEST_ASSERT(probe && out_val == 1); + + num_counters = get_num_counters(); + + for (i = 0; i < num_counters; i++) { + ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_GET_INFO, i, + 0, 0, 0, 0, 0); + + /* There can be gaps in logical counter indicies*/ + if (ret.error) + continue; + GUEST_ASSERT_NE(ret.value, 0); + + ctrinfo.value = ret.value; + + /** + * Accessibility check of hardware and read capability of firmware counters. + * The spec doesn't mandate any initial value. No need to check any value. + */ + if (ctrinfo.type == SBI_PMU_CTR_TYPE_HW) { + pmu_csr_read_num(ctrinfo.csr); + GUEST_ASSERT(illegal_handler_invoked); + } else if (ctrinfo.type == SBI_PMU_CTR_TYPE_FW) { + read_fw_counter(i, ctrinfo); + } + } + + GUEST_DONE(); +} + +static void run_vcpu(struct kvm_vcpu *vcpu) +{ + struct ucall uc; + + vcpu_run(vcpu); + switch (get_ucall(vcpu, &uc)) { + case UCALL_ABORT: + REPORT_GUEST_ASSERT(uc); + break; + case UCALL_DONE: + case UCALL_SYNC: + break; + default: + TEST_FAIL("Unknown ucall %lu", uc.cmd); + break; + } +} + +void test_vm_destroy(struct kvm_vm *vm) +{ + memset(ctrinfo_arr, 0, sizeof(union sbi_pmu_ctr_info) * RISCV_MAX_PMU_COUNTERS); + counter_mask_available = 0; + kvm_vm_free(vm); +} + +static void test_vm_basic_test(void *guest_code) +{ + struct kvm_vm *vm; + struct kvm_vcpu *vcpu; + + vm = vm_create_with_one_vcpu(&vcpu, guest_code); + __TEST_REQUIRE(__vcpu_has_sbi_ext(vcpu, KVM_RISCV_SBI_EXT_PMU), + "SBI PMU not available, skipping test"); + vm_init_vector_tables(vm); + /* Illegal instruction handler is required to verify read access without configuration */ + vm_install_exception_handler(vm, EXC_INST_ILLEGAL, guest_illegal_exception_handler); + + vcpu_init_vector_tables(vcpu); + run_vcpu(vcpu); + + test_vm_destroy(vm); +} + +static void test_vm_events_test(void *guest_code) +{ + struct kvm_vm *vm = NULL; + struct kvm_vcpu *vcpu = NULL; + + vm = vm_create_with_one_vcpu(&vcpu, guest_code); + __TEST_REQUIRE(__vcpu_has_sbi_ext(vcpu, KVM_RISCV_SBI_EXT_PMU), + "SBI PMU not available, skipping test"); + run_vcpu(vcpu); + + test_vm_destroy(vm); +} + +int main(void) +{ + test_vm_basic_test(test_pmu_basic_sanity); + pr_info("SBI PMU basic test : PASS\n"); + + test_vm_events_test(test_pmu_events); + pr_info("SBI PMU event verification test : PASS\n"); + + return 0; +}