[PATCH i-g-t 4/4] tests/intel/xe_eudebug_online: Add read/write pagefault online tests
Gwan-gyeong Mun
gwan-gyeong.mun at intel.com
Thu Nov 21 12:11:20 UTC 2024
On 11/19/24 5:58 PM, Hajda, Andrzej wrote:
>
> W dniu 15.11.2024 o 15:11, Gwan-gyeong Mun pisze:
>> Add read and write pagefault tests to xe_eudebug_online that checks if a
>> pagefault event is submitted by the KMD debugger when a pagefault occurs.
>>
>> Test that read (load instruction) and write(store instruction) attempt to
>> load or store access to unallocated memory, causing a pagefault.
>> Examine the address causing the page fault and the number of eu threads
>> causing the pagefault.
>>
>> Co-developed-by: Jonathan Cavitt <jonathan.cavitt at intel.com>
>> Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun at intel.com>
>> ---
>> tests/intel/xe_eudebug_online.c | 219 +++++++++++++++++++++++++++++++-
>> 1 file changed, 215 insertions(+), 4 deletions(-)
>>
>> diff --git a/tests/intel/xe_eudebug_online.c b/tests/intel/
>> xe_eudebug_online.c
>> index 0ef0d8093..eae0eb520 100644
>> --- a/tests/intel/xe_eudebug_online.c
>> +++ b/tests/intel/xe_eudebug_online.c
>> @@ -36,6 +36,8 @@
>> #define BB_IN_VRAM (1 << 11)
>> #define TARGET_IN_SRAM (1 << 12)
>> #define TARGET_IN_VRAM (1 << 13)
>> +#define SHADER_PAGEFAULT_READ (1 << 14)
>> +#define SHADER_PAGEFAULT_WRITE (1 << 15)
>> #define TRIGGER_UFENCE_SET_BREAKPOINT (1 << 24)
>> #define TRIGGER_RESUME_SINGLE_WALK (1 << 25)
>> #define TRIGGER_RESUME_PARALLEL_WALK (1 << 26)
>> @@ -45,6 +47,7 @@
>> #define TRIGGER_RESUME_DSS (1 << 30)
>> #define TRIGGER_RESUME_ONE (1 << 31)
>> +#define SHADER_PAGEFAULT (SHADER_PAGEFAULT_READ |
>> SHADER_PAGEFAULT_WRITE)
>> #define BB_REGION_BITMASK (BB_IN_SRAM | BB_IN_VRAM)
>> #define TARGET_REGION_BITMASK (TARGET_IN_SRAM | TARGET_IN_VRAM)
>> @@ -61,6 +64,8 @@
>> #define CACHING_VALUE(n) (CACHING_INIT_VALUE + (n))
>> #define SHADER_CANARY 0x01010101
>> +#define BAD_CANARY 0xf1f1f1f
>> +#define BAD_OFFSET (0x12345678ull << 12)
>> #define WALKER_X_DIM 4
>> #define WALKER_ALIGNMENT 16
>> @@ -123,6 +128,9 @@ static int get_number_of_threads(uint64_t flags)
>> if (flags & SHADER_MIN_THREADS)
>> return 16;
>> + if (flags & SHADER_PAGEFAULT)
>> + return 16;
>> +
>> if (flags & (TRIGGER_RESUME_ONE | TRIGGER_RESUME_SINGLE_WALK |
>> TRIGGER_RESUME_PARALLEL_WALK | SHADER_CACHING_SRAM |
>> SHADER_CACHING_VRAM))
>> return 32;
>> @@ -179,6 +187,16 @@ static struct gpgpu_shader *get_shader(int fd,
>> const unsigned int flags)
>> gpgpu_shader__common_target_write_u32(shader, s_dim.y +
>> i, CACHING_VALUE(i));
>> gpgpu_shader__nop(shader);
>> gpgpu_shader__breakpoint(shader);
>> + } else if (flags & SHADER_PAGEFAULT) {
>> + if (flags & SHADER_PAGEFAULT_READ)
>> + gpgpu_shader__read_page_fault(shader, BAD_OFFSET);
>> + else if (flags & SHADER_PAGEFAULT_WRITE)
>> + gpgpu_shader__write_offset(shader, BAD_OFFSET, BAD_CANARY);
>> +
>> + gpgpu_shader__label(shader, 0);
>> + gpgpu_shader__write_dword(shader, SHADER_CANARY, 0);
>> + gpgpu_shader__jump_neq(shader, 0, w_dim.y, STEERING_END_LOOP);
>> + gpgpu_shader__write_dword(shader, SHADER_CANARY, 0);
>> }
>> gpgpu_shader__eot(shader);
>> @@ -217,6 +235,17 @@ static int count_set_bits(void *ptr, size_t size)
>> return count;
>> }
>> +static int
>> +eu_attentions_xor_count(const uint32_t *a, const uint32_t *b,
>> uint32_t size)
>> +{
>> + int count = 0;
>> +
>> + for (int i = 0; i < size / 4 ; i++)
>> + count += igt_hweight(a[i] ^ b[i]);
>> +
>> + return count;
>> +}
>> +
>> static int count_canaries_eq(uint32_t *ptr, struct dim_t w_dim,
>> uint32_t value)
>> {
>> int count = 0;
>> @@ -636,7 +665,7 @@ static void eu_attention_resume_trigger(struct
>> xe_eudebug_debugger *d,
>> }
>> }
>> - if (d->flags & SHADER_LOOP) {
>> + if (d->flags & (SHADER_LOOP | SHADER_PAGEFAULT)) {
>> uint32_t threads = get_number_of_threads(d->flags);
>> uint32_t val = STEERING_END_LOOP;
>> @@ -746,6 +775,43 @@ static void
>> eu_attention_resume_single_step_trigger(struct xe_eudebug_debugger *
>> data->single_step_bitmask[i] &= ~att->bitmask[i];
>> }
>> +static void eu_attention_resume_pagefault_trigger(struct
>> xe_eudebug_debugger *d,
>> + struct drm_xe_eudebug_event *e)
>> +{
>> + struct drm_xe_eudebug_event_eu_attention *att = (void *) e;
>> + struct online_debug_data *data = d->ptr;
>> + uint32_t bitmask_size = att->bitmask_size;
>> + uint8_t *bitmask;
>> +
>> + if (data->last_eu_control_seqno > att->base.seqno)
>> + return;
>> +
>> + bitmask = calloc(1, att->bitmask_size);
>> +
>> + eu_ctl_stopped(d->fd, att->client_handle, att->exec_queue_handle,
>> + att->lrc_handle, bitmask, &bitmask_size);
>> + igt_assert(bitmask_size == att->bitmask_size);
>> +
>> + pthread_mutex_lock(&data->mutex);
>> +
>> + if (d->flags & SHADER_PAGEFAULT) {
>> + uint32_t threads = get_number_of_threads(d->flags);
>> + uint32_t val = STEERING_END_LOOP;
>> +
>> + igt_assert_eq(pwrite(data->vm_fd, &val, sizeof(uint32_t),
>> + data->target_offset + steering_offset(threads)),
>> + sizeof(uint32_t));
>> + fsync(data->vm_fd);
>> + }
>> + pthread_mutex_unlock(&data->mutex);
>> +
>> + data->last_eu_control_seqno = eu_ctl_resume(d->master_fd, d->fd,
>> att->client_handle,
>> + att->exec_queue_handle, att->lrc_handle,
>> + bitmask, att->bitmask_size);
>> +
>> + free(bitmask);
>> +}
>> +
>> static void open_trigger(struct xe_eudebug_debugger *d,
>> struct drm_xe_eudebug_event *e)
>> {
>> @@ -1015,7 +1081,7 @@ static void run_online_client(struct
>> xe_eudebug_client *c)
>> struct intel_bb *ibb;
>> struct intel_buf *buf;
>> uint32_t *ptr;
>> - int fd;
>> + int fd, vm_flags;
>> metadata[0] = calloc(2, sizeof(*metadata));
>> metadata[1] = calloc(2, sizeof(*metadata));
>> @@ -1025,7 +1091,7 @@ static void run_online_client(struct
>> xe_eudebug_client *c)
>> fd = xe_eudebug_client_open_driver(c);
>> /* Additional memory for steering control */
>> - if (c->flags & SHADER_LOOP || c->flags & SHADER_SINGLE_STEP)
>> + if (c->flags & SHADER_LOOP || c->flags & SHADER_SINGLE_STEP || c-
>> >flags & SHADER_PAGEFAULT)
>> s_dim.y++;
>> /* Additional memory for caching check */
>> if ((c->flags & SHADER_CACHING_SRAM) || (c->flags &
>> SHADER_CACHING_VRAM))
>> @@ -1045,7 +1111,11 @@ static void run_online_client(struct
>> xe_eudebug_client *c)
>> DRM_XE_DEBUG_METADATA_PROGRAM_MODULE,
>> 2 * sizeof(*metadata), metadata[1]);
>> - create.vm_id = xe_eudebug_client_vm_create(c, fd,
>> DRM_XE_VM_CREATE_FLAG_LR_MODE, 0);
>> + vm_flags = DRM_XE_VM_CREATE_FLAG_LR_MODE;
>> + vm_flags |= c->flags & SHADER_PAGEFAULT ?
>> DRM_XE_VM_CREATE_FLAG_FAULT_MODE : 0;
>> +
>> + create.vm_id = xe_eudebug_client_vm_create(c, fd, vm_flags, 0);
>> +
>> xe_eudebug_client_exec_queue_create(c, fd, &create);
>> ibb = xe_bb_create_on_offset(fd, create.exec_queue_id,
>> create.vm_id, bb_offset, bb_size,
>> @@ -1245,11 +1315,14 @@ match_attention_with_exec_queue(struct
>> xe_eudebug_event_log *log,
>> static void online_session_check(struct xe_eudebug_session *s, int
>> flags)
>> {
>> struct drm_xe_eudebug_event_eu_attention *ea = NULL;
>> + struct drm_xe_eudebug_event_pagefault *pf = NULL;
>> struct drm_xe_eudebug_event *event = NULL;
>> struct online_debug_data *data = s->client->ptr;
>> bool expect_exception = flags & DISABLE_DEBUG_MODE ? false : true;
>> int sum = 0;
>> int bitmask_size;
>> + int pagefault_threads = 0;
>> + uint32_t *ptr = NULL;
>> xe_eudebug_session_check(s, true, XE_EUDEBUG_FILTER_EVENT_VM_BIND |
>> XE_EUDEBUG_FILTER_EVENT_VM_BIND_OP |
>> @@ -1265,6 +1338,16 @@ static void online_session_check(struct
>> xe_eudebug_session *s, int flags)
>> igt_assert_eq(ea->bitmask_size, bitmask_size);
>> sum += count_set_bits(ea->bitmask, bitmask_size);
>> igt_assert(match_attention_with_exec_queue(s->debugger-
>> >log, ea));
>> + } else if (event->type == DRM_XE_EUDEBUG_EVENT_PAGEFAULT) {
>> + uint32_t after_offset = bitmask_size / sizeof(uint32_t);
>> + uint32_t resolved_offset = bitmask_size /
>> sizeof(uint32_t) * 2;
>> +
>> + pf = (struct drm_xe_eudebug_event_pagefault *)event;
>> + ptr = (uint32_t *) pf->bitmask;
>> + igt_assert_eq(pf->bitmask_size, bitmask_size * 3);
>> + pagefault_threads += eu_attentions_xor_count(ptr +
>> after_offset,
>> + ptr + resolved_offset,
>> + bitmask_size);
>> }
>> }
>> @@ -1279,6 +1362,9 @@ static void online_session_check(struct
>> xe_eudebug_session *s, int flags)
>> igt_assert(sum > 0);
>> else
>> igt_assert(sum == 0);
>> +
>> + if (flags & SHADER_PAGEFAULT)
>> + igt_assert(pagefault_threads > 0);
>> }
>> static void ufence_ack_trigger(struct xe_eudebug_debugger *d,
>> @@ -1302,6 +1388,55 @@ static void ufence_ack_set_bp_trigger(struct
>> xe_eudebug_debugger *d,
>> }
>> }
>> +static void pagefault_trigger(struct xe_eudebug_debugger *d,
>> + struct drm_xe_eudebug_event *e)
>> +{
>> + struct drm_xe_eudebug_event_pagefault *pf = (void *) e;
>> + int before_threads, after_threads, resolved_threads,
>> pagefault_threads;
>> + uint32_t attn_size = pf->bitmask_size / 3;
>> + uint32_t *ptr = (uint32_t *) pf->bitmask;
>> + uint32_t offset, before_offset = 0;
>> + uint32_t after_offset = attn_size / sizeof(uint32_t);
>> + uint32_t resolved_offset = attn_size / sizeof(uint32_t) * 2;
>> +
>> + before_threads = count_set_bits(ptr + before_offset, attn_size);
>> + after_threads = count_set_bits(ptr + after_offset, attn_size);
>> + resolved_threads = count_set_bits(ptr + resolved_offset, attn_size);
>> +
>> + pagefault_threads = eu_attentions_xor_count(ptr + after_offset,
>> + ptr + resolved_offset,
>> + attn_size);
>> +
>> + igt_debug("EVENT[%llu] pagefault; threads[before=%d, after=%d, "
>> + "resolved=%d, pagefault=%d] "
>> + "client[%llu], exec_queue[%llu], lrc[%llu],
>> bitmask_size[%d], "
>> + "pagefault_address[0x%llx]\n",
>> + pf->base.seqno, before_threads, after_threads,
>> resolved_threads,
>> + pagefault_threads, pf->client_handle, pf->exec_queue_handle,
>> + pf->lrc_handle, pf->bitmask_size,
>> + pf->pagefault_address);
>> +
>> + for (int idx = 0; idx < 3; idx++) {
>> + if (idx == 0) {
>> + igt_debug("=== Attentions before ===\n");
>> + offset = before_offset;
>> + } else if (idx == 1) {
>> + igt_debug("=== Attentions after ===\n");
>> + offset = after_offset;
>> + } else {
>> + igt_debug("=== Attentions resolved ===\n");
>> + offset = resolved_offset;
>> + }
>> +
>> + for (uint32_t i = 0; i < attn_size / sizeof(uint32_t); i += 2)
>> + igt_debug("bitmask[%d] = 0x%08x%08x\n", i / 2,
>> + ptr[offset + i], ptr[offset + i + 1]);
>> + }
>> +
>> + igt_assert(pagefault_threads > 0);
>
>
> Why not checking if pagefault_threads == num_of_threads ?
>
> I am not sure what is worth checking else, I wonder if we couldn't for
> example cause only some of test PF and check if they are reported
> correctly.
>
> Regarding the flow I see nothing suspicious, AFAIK.
>
In terms of identifying the eu thread that caused the pagefault, the igt
test case only verifies that there is at least one eu thread that caused
a pagefault, as there is only a guarantee that KMD will report the first
eu thread that caused a pagefault. Of course, if multiple eu threads
caused the pagefault while KMD was handling the pagefault, all of them
may be reported. The point here is that at least one eu thread is reported.
>
> Regards
>
> Andrzej
>
>
>> + igt_assert_eq_u64(pf->pagefault_address, BAD_OFFSET);
>> +}
>> +
>> /**
>> * SUBTEST: basic-breakpoint
>> * Description:
>> @@ -1383,6 +1518,77 @@ static void test_set_breakpoint_online(int fd,
>> struct drm_xe_engine_class_instan
>> online_debug_data_destroy(data);
>> }
>> +/**
>> + * SUBTEST: pagefault-read
>> + * Description:
>> + * Check whether KMD sends pagefault event for workload in debug
>> mode that
>> + * triggers a read pagefault.
>> + *
>> + * SUBTEST: pagefault-write
>> + * Description:
>> + * Check whether KMD sends pagefault event for workload in debug
>> mode that
>> + * triggers a write pagefault.
>> + */
>> +static void test_pagefault_online(int fd, struct
>> drm_xe_engine_class_instance *hwe,
>> + int flags)
>> +{
>> + struct xe_eudebug_session *s;
>> + struct online_debug_data *data;
>> + uint32_t val;
>> +
>> + data = online_debug_data_create(hwe);
>> + s = xe_eudebug_session_create(fd, run_online_client, flags, data);
>> +
>> + xe_eudebug_debugger_add_trigger(s->debugger,
>> DRM_XE_EUDEBUG_EVENT_OPEN,
>> + open_trigger);
>> + xe_eudebug_debugger_add_trigger(s->debugger,
>> DRM_XE_EUDEBUG_EVENT_EXEC_QUEUE,
>> + exec_queue_trigger);
>> + xe_eudebug_debugger_add_trigger(s->debugger,
>> DRM_XE_EUDEBUG_EVENT_EU_ATTENTION,
>> + eu_attention_debug_trigger);
>> + xe_eudebug_debugger_add_trigger(s->debugger,
>> DRM_XE_EUDEBUG_EVENT_EU_ATTENTION,
>> + eu_attention_resume_pagefault_trigger);
>> + xe_eudebug_debugger_add_trigger(s->debugger,
>> DRM_XE_EUDEBUG_EVENT_VM, vm_open_trigger);
>> + xe_eudebug_debugger_add_trigger(s->debugger,
>> DRM_XE_EUDEBUG_EVENT_METADATA,
>> + create_metadata_trigger);
>> + xe_eudebug_debugger_add_trigger(s->debugger,
>> DRM_XE_EUDEBUG_EVENT_VM_BIND_UFENCE,
>> + ufence_ack_trigger);
>> + xe_eudebug_debugger_add_trigger(s->debugger,
>> DRM_XE_EUDEBUG_EVENT_PAGEFAULT,
>> + pagefault_trigger);
>> +
>> + igt_assert_eq(xe_eudebug_debugger_attach(s->debugger, s->client),
>> 0);
>> + xe_eudebug_debugger_start_worker(s->debugger);
>> + xe_eudebug_client_start(s->client);
>> +
>> + /* wait for workload to start */
>> + igt_for_milliseconds(STARTUP_TIMEOUT_MS) {
>> + /* collect needed data from triggers */
>> + if (READ_ONCE(data->vm_fd) == -1 || READ_ONCE(data-
>> >target_size) == 0)
>> + continue;
>> +
>> + if (pread(data->vm_fd, &val, sizeof(val), data-
>> >target_offset) == sizeof(val))
>> + if (val != 0)
>> + break;
>> + }
>> +
>> + pthread_mutex_lock(&data->mutex);
>> + igt_assert(data->client_handle != -1);
>> + igt_assert(data->exec_queue_handle != -1);
>> +
>> + pthread_mutex_unlock(&data->mutex);
>> +
>> + xe_eudebug_client_wait_done(s->client);
>> +
>> + xe_eudebug_debugger_stop_worker(s->debugger, 1);
>> +
>> + xe_eudebug_event_log_print(s->debugger->log, true);
>> + xe_eudebug_event_log_print(s->client->log, true);
>> +
>> + online_session_check(s, s->flags);
>> +
>> + xe_eudebug_session_destroy(s);
>> + online_debug_data_destroy(data);
>> +}
>> +
>> /**
>> * SUBTEST: preempt-breakpoint
>> * Description:
>> @@ -2344,6 +2550,11 @@ igt_main
>> igt_subtest("breakpoint-many-sessions-tiles")
>> test_many_sessions_on_tiles(fd, true);
>> + test_gt_render_or_compute("pagefault-read", fd, hwe)
>> + test_pagefault_online(fd, hwe, SHADER_PAGEFAULT_READ);
>> + test_gt_render_or_compute("pagefault-write", fd, hwe)
>> + test_pagefault_online(fd, hwe, SHADER_PAGEFAULT_WRITE);
>> +
>> igt_fixture {
>> xe_eudebug_enable(fd, was_enabled);
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