On 4/20/24 8:17 PM, Atish Patra wrote: > 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 <[email protected]> > Reviewed-by: Anup Patel <[email protected]> > Signed-off-by: Atish Patra <[email protected]> LGTM
Reviewed-by: Muhammad Usama Anjum <[email protected]> > --- > .../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; > } -- BR, Muhammad Usama Anjum
