Verify PMU snapshot functionality by setting up the shared memory correctly and reading the counter values from the shared memory instead of the CSR.
Reviewed-by: Andrew Jones ajones@ventanamicro.com Reviewed-by: Anup Patel anup@brainfault.org Signed-off-by: Atish Patra atishp@rivosinc.com --- .../testing/selftests/kvm/include/riscv/sbi.h | 25 +++ .../selftests/kvm/lib/riscv/processor.c | 12 ++ .../selftests/kvm/riscv/sbi_pmu_test.c | 144 ++++++++++++++++++ 3 files changed, 181 insertions(+)
diff --git a/tools/testing/selftests/kvm/include/riscv/sbi.h b/tools/testing/selftests/kvm/include/riscv/sbi.h index 6675ca673c77..046b432ae896 100644 --- a/tools/testing/selftests/kvm/include/riscv/sbi.h +++ b/tools/testing/selftests/kvm/include/riscv/sbi.h @@ -8,6 +8,12 @@ #ifndef SELFTEST_KVM_SBI_H #define SELFTEST_KVM_SBI_H
+/* SBI spec version fields */ +#define SBI_SPEC_VERSION_DEFAULT 0x1 +#define SBI_SPEC_VERSION_MAJOR_SHIFT 24 +#define SBI_SPEC_VERSION_MAJOR_MASK 0x7f +#define SBI_SPEC_VERSION_MINOR_MASK 0xffffff + /* SBI return error codes */ #define SBI_SUCCESS 0 #define SBI_ERR_FAILURE -1 @@ -33,6 +39,9 @@ enum sbi_ext_id { };
enum sbi_ext_base_fid { + SBI_EXT_BASE_GET_SPEC_VERSION = 0, + SBI_EXT_BASE_GET_IMP_ID, + SBI_EXT_BASE_GET_IMP_VERSION, SBI_EXT_BASE_PROBE_EXT = 3, }; enum sbi_ext_pmu_fid { @@ -60,6 +69,12 @@ union sbi_pmu_ctr_info { }; };
+struct riscv_pmu_snapshot_data { + u64 ctr_overflow_mask; + u64 ctr_values[64]; + u64 reserved[447]; +}; + struct sbiret { long error; long value; @@ -113,4 +128,14 @@ struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
bool guest_sbi_probe_extension(int extid, long *out_val);
+/* Make SBI version */ +static inline unsigned long sbi_mk_version(unsigned long major, + unsigned long minor) +{ + return ((major & SBI_SPEC_VERSION_MAJOR_MASK) << SBI_SPEC_VERSION_MAJOR_SHIFT) + | (minor & SBI_SPEC_VERSION_MINOR_MASK); +} + +unsigned long get_host_sbi_spec_version(void); + #endif /* SELFTEST_KVM_SBI_H */ diff --git a/tools/testing/selftests/kvm/lib/riscv/processor.c b/tools/testing/selftests/kvm/lib/riscv/processor.c index e8211f5d6863..ccb35573749c 100644 --- a/tools/testing/selftests/kvm/lib/riscv/processor.c +++ b/tools/testing/selftests/kvm/lib/riscv/processor.c @@ -502,3 +502,15 @@ bool guest_sbi_probe_extension(int extid, long *out_val)
return true; } + +unsigned long get_host_sbi_spec_version(void) +{ + struct sbiret ret; + + ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_GET_SPEC_VERSION, 0, + 0, 0, 0, 0, 0); + + GUEST_ASSERT(!ret.error); + + return ret.value; +} diff --git a/tools/testing/selftests/kvm/riscv/sbi_pmu_test.c b/tools/testing/selftests/kvm/riscv/sbi_pmu_test.c index 7c81691e39c5..9002ff451abf 100644 --- a/tools/testing/selftests/kvm/riscv/sbi_pmu_test.c +++ b/tools/testing/selftests/kvm/riscv/sbi_pmu_test.c @@ -19,6 +19,11 @@ #define RISCV_MAX_PMU_COUNTERS 64 union sbi_pmu_ctr_info ctrinfo_arr[RISCV_MAX_PMU_COUNTERS];
+/* Snapshot shared memory data */ +#define PMU_SNAPSHOT_GPA_BASE BIT(30) +static void *snapshot_gva; +static vm_paddr_t snapshot_gpa; + /* Cache the available counters in a bitmask */ static unsigned long counter_mask_available;
@@ -186,6 +191,32 @@ static unsigned long read_counter(int idx, union sbi_pmu_ctr_info ctrinfo) return counter_val; }
+static inline void verify_sbi_requirement_assert(void) +{ + long out_val = 0; + bool probe; + + probe = guest_sbi_probe_extension(SBI_EXT_PMU, &out_val); + GUEST_ASSERT(probe && out_val == 1); + + if (get_host_sbi_spec_version() < sbi_mk_version(2, 0)) + __GUEST_ASSERT(0, "SBI implementation version doesn't support PMU Snapshot"); +} + +static void snapshot_set_shmem(vm_paddr_t gpa, unsigned long flags) +{ + unsigned long lo = (unsigned long)gpa; +#if __riscv_xlen == 32 + unsigned long hi = (unsigned long)(gpa >> 32); +#else + unsigned long hi = gpa == -1 ? -1 : 0; +#endif + struct sbiret ret = sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_SNAPSHOT_SET_SHMEM, + lo, hi, flags, 0, 0, 0); + + GUEST_ASSERT(ret.value == 0 && ret.error == 0); +} + static void test_pmu_event(unsigned long event) { unsigned long counter; @@ -234,6 +265,59 @@ static void test_pmu_event(unsigned long event) stop_reset_counter(counter, 0); }
+static void test_pmu_event_snapshot(unsigned long event) +{ + unsigned long counter; + unsigned long counter_value_pre, counter_value_post; + unsigned long counter_init_value = 100; + struct riscv_pmu_snapshot_data *snapshot_data = snapshot_gva; + + 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, SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT); + + /* The counter value is updated w.r.t relative index of cbase */ + counter_value_post = READ_ONCE(snapshot_data->ctr_values[0]); + __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. + */ + WRITE_ONCE(snapshot_data->ctr_values[0], ULONG_MAX/2); + start_counter(counter, SBI_PMU_START_FLAG_INIT_SNAPSHOT, 0); + stop_counter(counter, SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT); + counter_value_pre = READ_ONCE(snapshot_data->ctr_values[0]); + + WRITE_ONCE(snapshot_data->ctr_values[0], counter_init_value); + start_counter(counter, SBI_PMU_START_FLAG_INIT_SNAPSHOT, 0); + stop_counter(counter, SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT); + counter_value_post = READ_ONCE(snapshot_data->ctr_values[0]); + __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 */ + WRITE_ONCE(snapshot_data->ctr_values[0], counter_init_value); + start_counter(counter, SBI_PMU_START_FLAG_INIT_SNAPSHOT, 0); + dummy_func_loop(10000); + stop_counter(counter, SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT); + + counter_value_post = READ_ONCE(snapshot_data->ctr_values[0]); + __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; @@ -301,6 +385,34 @@ static void test_pmu_basic_sanity(void) GUEST_DONE(); }
+static void test_pmu_events_snaphost(void) +{ + int num_counters = 0; + struct riscv_pmu_snapshot_data *snapshot_data = snapshot_gva; + int i; + + /* Verify presence of SBI PMU and minimum requrired SBI version */ + verify_sbi_requirement_assert(); + + snapshot_set_shmem(snapshot_gpa, 0); + + /* Get the counter details */ + num_counters = get_num_counters(); + update_counter_info(num_counters); + + /* Validate shared memory access */ + GUEST_ASSERT_EQ(READ_ONCE(snapshot_data->ctr_overflow_mask), 0); + for (i = 0; i < num_counters; i++) { + if (counter_mask_available & (BIT(i))) + GUEST_ASSERT_EQ(READ_ONCE(snapshot_data->ctr_values[i]), 0); + } + /* Only these two events are guranteed to be present */ + test_pmu_event_snapshot(SBI_PMU_HW_CPU_CYCLES); + test_pmu_event_snapshot(SBI_PMU_HW_INSTRUCTIONS); + + GUEST_DONE(); +} + static void run_vcpu(struct kvm_vcpu *vcpu) { struct ucall uc; @@ -357,6 +469,35 @@ static void test_vm_events_test(void *guest_code) test_vm_destroy(vm); }
+static void test_vm_setup_snapshot_mem(struct kvm_vm *vm, struct kvm_vcpu *vcpu) +{ + /* PMU Snapshot requires single page only */ + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, PMU_SNAPSHOT_GPA_BASE, 1, 1, 0); + /* PMU_SNAPSHOT_GPA_BASE is identity mapped */ + virt_map(vm, PMU_SNAPSHOT_GPA_BASE, PMU_SNAPSHOT_GPA_BASE, 1); + + snapshot_gva = (void *)(PMU_SNAPSHOT_GPA_BASE); + snapshot_gpa = addr_gva2gpa(vcpu->vm, (vm_vaddr_t)snapshot_gva); + sync_global_to_guest(vcpu->vm, snapshot_gva); + sync_global_to_guest(vcpu->vm, snapshot_gpa); +} + +static void test_vm_events_snapshot_test(void *guest_code) +{ + struct kvm_vm *vm = NULL; + 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"); + + test_vm_setup_snapshot_mem(vm, vcpu); + + run_vcpu(vcpu); + + test_vm_destroy(vm); +} + int main(void) { test_vm_basic_test(test_pmu_basic_sanity); @@ -365,5 +506,8 @@ int main(void) test_vm_events_test(test_pmu_events); pr_info("SBI PMU event verification test : PASS\n");
+ test_vm_events_snapshot_test(test_pmu_events_snaphost); + pr_info("SBI PMU event verification with snapshot test : PASS\n"); + return 0; }