Re: [PATCH i-g-t v3 5/8] tests/intel/xe_madvise: Add dontneed-before-exec subtest

["Sharma, Nishit" <nishit.sharma@intel.com>]

On 2/23/2026 10:40 AM, Gurram, Pravalika wrote:
>
>> -----Original Message-----
>> From: Yadav, Arvind <arvind.yadav@intel.com>
>> Sent: Tuesday, 17 February, 2026 08:04 AM
>> To: igt-dev@lists.freedesktop.org
>> Cc: Brost, Matthew <matthew.brost@intel.com>; Ghimiray, Himal Prasad
>> <himal.prasad.ghimiray@intel.com>; thomas.hellstrom@linux.intel.com;
>> Sharma, Nishit <nishit.sharma@intel.com>; Gurram, Pravalika
>> <pravalika.gurram@intel.com>
>> Subject: [PATCH i-g-t v3 5/8] tests/intel/xe_madvise: Add dontneed-before-
>> exec subtest
>>
>> This test validates GPU execution behavior when a data BO is purged before
>> submission. The test creates a batch that writes to a data BO, purges the data
>> BO (while keeping the batch BO valid to avoid GPU reset), then submits for
>> execution. With VM_CREATE_FLAG_SCRATCH_PAGE, the GPU write may
>> succeed by landing on scratch memory instead of the purged BO,
>> demonstrating graceful handling of purged memory during GPU operations.
>>
>> Cc: Nishit Sharma <nishit.sharma@intel.com>
>> Cc: Pravalika Gurram <pravalika.gurram@intel.com>
>> Cc: Matthew Brost <matthew.brost@intel.com>
>> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
>> Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
>> Signed-off-by: Arvind Yadav <arvind.yadav@intel.com>
>> ---
>>   tests/intel/xe_madvise.c | 140
>> +++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 140 insertions(+)
>>
>> diff --git a/tests/intel/xe_madvise.c b/tests/intel/xe_madvise.c index
>> 5c6a24553..42cf1b3e5 100644
>> --- a/tests/intel/xe_madvise.c
>> +++ b/tests/intel/xe_madvise.c
>> @@ -19,7 +19,11 @@
>>
>>   /* Purgeable test constants */
>>   #define PURGEABLE_ADDR		0x1a0000
>> +#define PURGEABLE_BATCH_ADDR	0x3c0000
>>   #define PURGEABLE_BO_SIZE	4096
>> +#define PURGEABLE_FENCE_VAL	0xbeef
>> +#define PURGEABLE_TEST_PATTERN	0xc0ffee
>> +#define PURGEABLE_DEAD_PATTERN	0xdead
>>
>>   /**
>>    * trigger_memory_pressure - Fill VRAM + 25% to force purgeable reclaim @@
>> -144,6 +148,62 @@ static void purgeable_setup_simple_bo(int fd, uint32_t
>> *vm, uint32_t *bo,
>>   	xe_wait_ufence(fd, &sync_val, 1, 0, NSEC_PER_SEC);  }
>>
>> +/**
>> + * purgeable_setup_batch_and_data - Setup VM with batch and data BOs
>> +for GPU exec
>> + * @fd: DRM file descriptor
>> + * @vm: Output VM handle
>> + * @bind_engine: Output bind engine handle
>> + * @batch_bo: Output batch BO handle
>> + * @data_bo: Output data BO handle
>> + * @batch: Output batch buffer pointer
>> + * @data: Output data buffer pointer
>> + * @batch_addr: Batch virtual address
>> + * @data_addr: Data virtual address
>> + * @batch_size: Batch buffer size
>> + * @data_size: Data buffer size
>> + *
>> + * Helper to create VM, bind engine, batch and data BOs, and bind them.
>> + */
>> +static void purgeable_setup_batch_and_data(int fd, uint32_t *vm,
>> +					   uint32_t *bind_engine,
>> +					   uint32_t *batch_bo,
>> +					   uint32_t *data_bo,
>> +					   uint32_t **batch,
>> +					   uint32_t **data,
>> +					   uint64_t batch_addr,
>> +					   uint64_t data_addr,
>> +					   size_t batch_size,
>> +					   size_t data_size)
>> +{
>> +	struct drm_xe_sync sync = {
>> +		.type = DRM_XE_SYNC_TYPE_USER_FENCE,
>> +		.flags = DRM_XE_SYNC_FLAG_SIGNAL,
>> +		.timeline_value = PURGEABLE_FENCE_VAL,
>> +	};
>> +	uint64_t vm_sync = 0;
>> +
>> +	*vm = xe_vm_create(fd, DRM_XE_VM_CREATE_FLAG_SCRATCH_PAGE,
>> 0);
>> +	*bind_engine = xe_bind_exec_queue_create(fd, *vm, 0);
>> +
>> +	/* Create and bind batch BO */
>> +	*batch_bo = xe_bo_create(fd, *vm, batch_size, vram_if_possible(fd,
>> 0),
>> +
>> DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM);
>> +	*batch = xe_bo_map(fd, *batch_bo, batch_size);
>> +
>> +	sync.addr = to_user_pointer(&vm_sync);
>> +	xe_vm_bind_async(fd, *vm, *bind_engine, *batch_bo, 0, batch_addr,
>> batch_size, &sync, 1);
>> +	xe_wait_ufence(fd, &vm_sync, PURGEABLE_FENCE_VAL, 0,
>> NSEC_PER_SEC);
>> +
>> +	/* Create and bind data BO */
>> +	*data_bo = xe_bo_create(fd, *vm, data_size, vram_if_possible(fd, 0),
>> +
>> 	DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM);
>> +	*data = xe_bo_map(fd, *data_bo, data_size);
>> +
>> +	vm_sync = 0;
>> +	xe_vm_bind_async(fd, *vm, *bind_engine, *data_bo, 0, data_addr,
>> data_size, &sync, 1);
>> +	xe_wait_ufence(fd, &vm_sync, PURGEABLE_FENCE_VAL, 0,
>> NSEC_PER_SEC); }
>> +
>>   /**
>>    * SUBTEST: dontneed-before-mmap
>>    * Description: Mark BO as DONTNEED before mmap, verify mmap fails or
>> SIGBUS on access @@ -244,6 +304,80 @@ static void
>> test_dontneed_after_mmap(int fd, struct drm_xe_engine_class_instance
>>   	xe_vm_destroy(fd, vm);
>>   }
>>
>> +/**
>> + * SUBTEST: dontneed-before-exec
>> + * Description: Mark BO as DONTNEED before GPU exec, verify GPU
>> +behavior with SCRATCH_PAGE
>> + * Test category: functionality test
>> + */
>> +static void test_dontneed_before_exec(int fd, struct
>> +drm_xe_engine_class_instance *hwe) {
>> +	uint32_t vm, exec_queue, bo, batch_bo, bind_engine;
>> +	uint64_t data_addr = PURGEABLE_ADDR;
>> +	uint64_t batch_addr = PURGEABLE_BATCH_ADDR;
>> +	size_t data_size = PURGEABLE_BO_SIZE;
>> +	size_t batch_size = PURGEABLE_BO_SIZE;
>> +	struct drm_xe_sync sync[1] = {
>> +		{ .type = DRM_XE_SYNC_TYPE_USER_FENCE,
>> +		  .flags = DRM_XE_SYNC_FLAG_SIGNAL,
>> +		  .timeline_value = PURGEABLE_FENCE_VAL },
>> +	};
>> +	struct drm_xe_exec exec = {
>> +		.num_batch_buffer = 1,
>> +		.num_syncs = 1,
>> +		.syncs = to_user_pointer(sync),
>> +	};
>> +	uint32_t *data, *batch;
>> +	uint64_t vm_sync = 0;
>> +	int b, ret;
>> +
>> +	purgeable_setup_batch_and_data(fd, &vm, &bind_engine,
>> &batch_bo,
>> +				       &bo, &batch, &data, batch_addr,
>> +				       data_addr, batch_size, data_size);
>> +
>> +	/* Prepare batch */
>> +	b = 0;
>> +	batch[b++] = MI_STORE_DWORD_IMM_GEN4;
>> +	batch[b++] = data_addr;
>> +	batch[b++] = data_addr >> 32;
>> +	batch[b++] = PURGEABLE_DEAD_PATTERN;
>> +	batch[b++] = MI_BATCH_BUFFER_END;
>> +
>> +	/* Phase 1: Purge data BO, batch BO still valid */
>> +	igt_assert(purgeable_mark_and_verify_purged(fd, vm, data_addr,
>> +data_size));
Resource cleanup?
>> +
>> +	exec_queue = xe_exec_queue_create(fd, vm, hwe, 0);
>> +	exec.exec_queue_id = exec_queue;
>> +	exec.address = batch_addr;
>> +
>> +	vm_sync = 0;
>> +	sync[0].addr = to_user_pointer(&vm_sync);
>> +
>> +	/*
>> +	 * VM has SCRATCH_PAGE — exec may succeed with the GPU write
>> +	 * landing on scratch instead of the purged data BO.
>> +	 */
>> +	ret = __xe_exec(fd, &exec);
>> +	if (ret == 0) {
>> +		int64_t timeout = NSEC_PER_SEC;
>> +
>> +		__xe_wait_ufence(fd, &vm_sync, PURGEABLE_FENCE_VAL,
>> +				 exec_queue, &timeout);
>> +	}
>> +
>> +	/*
>> +	 * Don't purge the batch BO — GPU would fetch zeroed scratch
>> +	 * instructions and trigger an engine reset.
>> +	 */
>> +
>> +	munmap(data, data_size);
>> +	munmap(batch, batch_size);
>> +	gem_close(fd, bo);
>> +	gem_close(fd, batch_bo);
>> +	xe_exec_queue_destroy(fd, bind_engine);
>> +	xe_exec_queue_destroy(fd, exec_queue);
>> +	xe_vm_destroy(fd, vm);
>> +}
>> +
>>   int igt_main()
>>   {
>>   	struct drm_xe_engine_class_instance *hwe; @@ -266,6 +400,12 @@
>> int igt_main()
>>   			break;
>>   		}
>>
>> +	igt_subtest("dontneed-before-exec")
>> +		xe_for_each_engine(fd, hwe) {
>> +			test_dontneed_before_exec(fd, hwe);
>> +			break;
>> +		}
>> +
>>   	igt_fixture() {
>>   		xe_device_put(fd);
>>   		drm_close_driver(fd);
> Reviewed-by: Pravalika Gurram <pravalika.gurram@intel.com>
>> --
>> 2.43.0