On 3/2/24 04:13, Andrew Jones wrote:
On Wed, Feb 28, 2024 at 05:01:29PM -0800, 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. Signed-off-by: Atish Patra <atishp@xxxxxxxxxxxx> --- .../selftests/kvm/include/riscv/processor.h | 25 ++++ .../selftests/kvm/lib/riscv/processor.c | 12 ++ tools/testing/selftests/kvm/riscv/sbi_pmu.c | 124 ++++++++++++++++++ 3 files changed, 161 insertions(+) diff --git a/tools/testing/selftests/kvm/include/riscv/processor.h b/tools/testing/selftests/kvm/include/riscv/processor.h index a49a39c8e8d4..e114d039e87b 100644 --- a/tools/testing/selftests/kvm/include/riscv/processor.h +++ b/tools/testing/selftests/kvm/include/riscv/processor.h @@ -173,6 +173,7 @@ enum sbi_ext_id { };enum sbi_ext_base_fid {+ SBI_EXT_BASE_GET_IMP_VERSION = 2, SBI_EXT_BASE_PROBE_EXT = 3, };@@ -201,6 +202,12 @@ 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; @@ -247,6 +254,14 @@ enum sbi_pmu_ctr_type { #define SBI_PMU_STOP_FLAG_RESET (1 << 0) #define SBI_PMU_STOP_FLAG_TAKE_SNAPSHOT BIT(1)+#define SBI_STA_SHMEM_DISABLE -1unrelated change
Dropped it.
+ +/* 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 + struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0, unsigned long arg1, unsigned long arg2, unsigned long arg3, unsigned long arg4, @@ -254,6 +269,16 @@ 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; +}We should probably just synch sbi.h into tools, since we need plenty from it.
As of now I have created sbi.h and moved all the definitions there. There is a still lot of difference between sbi.h. Do we really want to bring everything in ? Should we adopt kvmtool like policy to sync sbi.h
or just do it as new test cases need sbi.h?I can send another version with syncing sbi.h if you still think that's better.
+ +unsigned long get_host_sbi_impl_version(void); + static inline void local_irq_enable(void) { csr_set(CSR_SSTATUS, SR_SIE); diff --git a/tools/testing/selftests/kvm/lib/riscv/processor.c b/tools/testing/selftests/kvm/lib/riscv/processor.c index ec66d331a127..b0162d923e38 100644 --- a/tools/testing/selftests/kvm/lib/riscv/processor.c +++ b/tools/testing/selftests/kvm/lib/riscv/processor.c @@ -499,3 +499,15 @@ bool guest_sbi_probe_extension(int extid, long *out_val)return true;} + +unsigned long get_host_sbi_impl_version(void) +{ + struct sbiret ret; + + ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_GET_IMP_VERSION, 0, + 0, 0, 0, 0, 0); + + GUEST_ASSERT(!ret.error); + + return ret.value; +} diff --git a/tools/testing/selftests/kvm/riscv/sbi_pmu.c b/tools/testing/selftests/kvm/riscv/sbi_pmu.c index fc1fc5eea99e..8ea2a6db6610 100644 --- a/tools/testing/selftests/kvm/riscv/sbi_pmu.c +++ b/tools/testing/selftests/kvm/riscv/sbi_pmu.c @@ -21,6 +21,11 @@ #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 (1 << 30) +static void *snapshot_gva; +static vm_paddr_t snapshot_gpa; + /* Cache the available counters in a bitmask */ static unsigned long counter_mask_available;@@ -173,6 +178,20 @@ static void stop_counter(unsigned long counter, unsigned long stop_flags)counter, ret.error); }+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; @@ -207,6 +226,43 @@ static void test_pmu_event(unsigned long event) stop_counter(counter, SBI_PMU_STOP_FLAG_RESET); }+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, + "counter_value_post %lx counter_value_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_FROM_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, + "counter_value_post %lx counter_init_value %lx for counter\n", + counter_value_post, counter_init_value); + + stop_counter(counter, SBI_PMU_STOP_FLAG_RESET);This function is almost identical to test_pmu_event(). If we change one, we'll likely have to change the other. We should have a single function which can be used by both tests. We can do that by passing a function pointer for the read which is different for non-snapshot and snapshot.
There are more difference than just read function. Stop/start takes snapshot specific flag. We also have to update the counter in the shared memory. If we combine the two functions to a single one, we will end up with bunch of if else condition which I don't like.
I am okay modifying it if you feel strongly about it though.
+} + static void test_invalid_event(void) { struct sbiret ret; @@ -270,6 +326,41 @@ static void test_pmu_basic_sanity(int cpu) GUEST_DONE(); }+static void test_pmu_events_snaphost(int cpu)unnecessary cpu parameter
Removed.
+{ + long out_val = 0; + bool probe; + int num_counters = 0; + unsigned long sbi_impl_version; + struct riscv_pmu_snapshot_data *snapshot_data = snapshot_gva; + int i; + + probe = guest_sbi_probe_extension(SBI_EXT_PMU, &out_val); + GUEST_ASSERT(probe && out_val == 1); + + sbi_impl_version = get_host_sbi_impl_version(); + if (sbi_impl_version >= sbi_mk_version(2, 0)) + __GUEST_ASSERT(0, "SBI implementation version doesn't support PMU Snapshot"); + + 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 & (1UL << i))BIT()
Done.
+ 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; @@ -328,6 +419,36 @@ 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)+{ + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, PMU_SNAPSHOT_GPA_BASE, 1, 1, 0); + /* PMU Snapshot requires single page only */This comment should go above the memory region add+ virt_map(vm, PMU_SNAPSHOT_GPA_BASE, PMU_SNAPSHOT_GPA_BASE, 1); + + /* PMU_SNAPSHOT_GPA_BASE is identity mapped */This comment should go above the virt_map
Fixed.
+ 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 = NULL;nit: no need to set to NULL+ + vm = vm_create_with_one_vcpu(&vcpu, guest_code); + __TEST_REQUIRE(__vcpu_has_ext(vcpu, RISCV_ISA_EXT_REG(KVM_RISCV_SBI_EXT_PMU)),RISCV_SBI_EXT_REG
Updated to use the new helper functions as suggested in the earlier patch.
+ "SBI PMU not available, skipping test"); + + test_vm_setup_snapshot_mem(vm, vcpu); + + vcpu_args_set(vcpu, 1, 0);no need to set args
Fixed.
+ run_vcpu(vcpu); + + test_vm_destroy(vm); +} + int main(void) { test_vm_basic_test(test_pmu_basic_sanity); @@ -336,5 +457,8 @@ 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; } -- 2.34.1Thanks, drew
