Re: [PATCH i-g-t v6 8/9] tests/intel/xe_madvise: Add per-vma-tracking subtest

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

On 3/25/2026 6:14 PM, Arvind Yadav wrote:
> This test validates that purgeable state is tracked per-VMA when a
> single BO is bound in multiple VMs. The test creates one BO shared
> across two VMs at different virtual addresses. It verifies that marking
> only one VMA as DONTNEED does not make the BO purgeable, but marking
> both VMAs as DONTNEED allows the kernel to purge the shared BO. This
> ensures proper per-VMA tracking for shared memory.
>
> v4:
>    -  The comment now clarifies that triggering pressure. (Nishit)
>
> v6:
>    - Move resource cleanup before igt_skip() to avoid leaking VM and BO
>      handles on platforms where memory pressure cannot be induced; replace
>      igt_assert_eq(retained, 0) with a graceful skip. (Nishit)
>
> Cc: Matthew Brost <matthew.brost@intel.com>
> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
> Cc: Nishit Sharma <nishit.sharma@intel.com>
> Cc: Pravalika Gurram <pravalika.gurram@intel.com>
> Signed-off-by: Arvind Yadav <arvind.yadav@intel.com>
> ---
>   tests/intel/xe_madvise.c | 114 +++++++++++++++++++++++++++++++++++++++
>   1 file changed, 114 insertions(+)
>
> diff --git a/tests/intel/xe_madvise.c b/tests/intel/xe_madvise.c
> index 28ea81442..6c0a563d8 100644
> --- a/tests/intel/xe_madvise.c
> +++ b/tests/intel/xe_madvise.c
> @@ -28,6 +28,7 @@ static bool xe_has_purgeable_support(int fd)
>   
>   /* Purgeable test constants */
>   #define PURGEABLE_ADDR		0x1a0000
> +#define PURGEABLE_ADDR2		0x2b0000
>   #define PURGEABLE_BATCH_ADDR	0x3c0000
>   #define PURGEABLE_BO_SIZE	4096
>   #define PURGEABLE_FENCE_VAL	0xbeef
> @@ -267,6 +268,58 @@ static void purgeable_setup_batch_and_data(int fd, uint32_t *vm,
>   	xe_wait_ufence(fd, &vm_sync, PURGEABLE_FENCE_VAL, 0, NSEC_PER_SEC);
>   }
>   
> +/**
> + * purgeable_setup_two_vms_shared_bo - Setup two VMs with one shared BO
> + * @fd: DRM file descriptor
> + * @vm1: Output first VM handle
> + * @vm2: Output second VM handle
> + * @bo: Output shared BO handle
> + * @addr1: Virtual address in VM1
> + * @addr2: Virtual address in VM2
> + * @size: Size of the BO
> + * @use_scratch: Whether to use scratch page flag for VMs
> + *
> + * Helper to create two VMs and bind one shared BO in both VMs.
> + * Returns mapped pointer to the BO.
> + */
> +static void *purgeable_setup_two_vms_shared_bo(int fd, uint32_t *vm1, uint32_t *vm2,
> +					       uint32_t *bo, uint64_t addr1,
> +					       uint64_t addr2, size_t size,
> +					       bool use_scratch)
> +{
> +	struct drm_xe_sync sync = {
> +		.type = DRM_XE_SYNC_TYPE_USER_FENCE,
> +		.flags = DRM_XE_SYNC_FLAG_SIGNAL,
> +		.timeline_value = 1,
> +	};
> +	uint64_t sync_val = 0;
> +	void *map;
> +
> +	/* Create two VMs */
> +	*vm1 = xe_vm_create(fd, use_scratch ? DRM_XE_VM_CREATE_FLAG_SCRATCH_PAGE : 0, 0);
> +	*vm2 = xe_vm_create(fd, use_scratch ? DRM_XE_VM_CREATE_FLAG_SCRATCH_PAGE : 0, 0);
> +
> +	/* Create shared BO */
> +	*bo = xe_bo_create(fd, 0, size, vram_if_possible(fd, 0),
> +			   DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM);
> +
> +	map = xe_bo_map(fd, *bo, size);
> +	memset(map, 0xAB, size);
> +
> +	/* Bind BO in VM1 */
> +	sync.addr = to_user_pointer(&sync_val);
> +	sync_val = 0;
> +	xe_vm_bind_async(fd, *vm1, 0, *bo, 0, addr1, size, &sync, 1);
> +	xe_wait_ufence(fd, &sync_val, 1, 0, NSEC_PER_SEC);
> +
> +	/* Bind BO in VM2 */
> +	sync_val = 0;
> +	xe_vm_bind_async(fd, *vm2, 0, *bo, 0, addr2, size, &sync, 1);
> +	xe_wait_ufence(fd, &sync_val, 1, 0, NSEC_PER_SEC);
> +
> +	return map;
> +}
> +
>   /**
>    * SUBTEST: dontneed-before-mmap
>    * Description: Mark BO as DONTNEED before mmap, verify mmap() fails with -EBUSY
> @@ -546,6 +599,61 @@ static void test_dontneed_after_exec(int fd, struct drm_xe_engine_class_instance
>   	xe_vm_destroy(fd, vm);
>   }
>   
> +/**
> + * SUBTEST: per-vma-tracking
> + * Description: One BO in two VMs becomes purgeable only when both VMAs are DONTNEED
> + * Test category: functionality test
> + */
> +static void test_per_vma_tracking(int fd, struct drm_xe_engine_class_instance *hwe)
> +{
> +	uint32_t bo, vm1, vm2;
> +	uint64_t addr1 = PURGEABLE_ADDR;
> +	uint64_t addr2 = PURGEABLE_ADDR2;
> +	size_t bo_size = PURGEABLE_BO_SIZE;
> +	uint32_t retained;
> +	void *map;
> +
> +	map = purgeable_setup_two_vms_shared_bo(fd, &vm1, &vm2, &bo,
> +						addr1, addr2,
> +						bo_size, false);
> +
> +	/* Mark VMA1 as DONTNEED */
> +	retained = xe_vm_madvise_purgeable(fd, vm1, addr1, bo_size,
> +					   DRM_XE_VMA_PURGEABLE_STATE_DONTNEED);
> +	igt_assert_eq(retained, 1);

As per description  if VM1 is set to DONTNEED it'll not purge untill VM2 
also set to DONTNEED. So retained = 1 is expected which also verifies

BO is purged or not, if returned 0, So below VM1 WILLNEED check can be 
dropped.

> +
> +	/* Verify BO NOT purgeable (VMA2 still WILLNEED) */
> +	retained = xe_vm_madvise_purgeable(fd, vm1, addr1, bo_size,
> +					   DRM_XE_VMA_PURGEABLE_STATE_WILLNEED);
> +	igt_assert_eq(retained, 1);
> +
> +	/* Mark both VMAs as DONTNEED */
> +	retained = xe_vm_madvise_purgeable(fd, vm1, addr1, bo_size,
> +					   DRM_XE_VMA_PURGEABLE_STATE_DONTNEED);
> +	igt_assert_eq(retained, 1);
> +
> +	retained = xe_vm_madvise_purgeable(fd, vm2, addr2, bo_size,
> +					   DRM_XE_VMA_PURGEABLE_STATE_DONTNEED);
> +	igt_assert_eq(retained, 1);
> +
> +	/*
> +	 * Trigger pressure and verify BO was purged.
> +	 * Using vm1 is sufficient since both VMAs are DONTNEED - kernel can purge the BO.
> +	 */
> +	trigger_memory_pressure(fd, vm1);
> +
> +	retained = xe_vm_madvise_purgeable(fd, vm1, addr1, bo_size,
> +					   DRM_XE_VMA_PURGEABLE_STATE_WILLNEED);
Expecting 0 (for purge) here, right? Can we put a check over here?
> +	munmap(map, bo_size);
> +	gem_close(fd, bo);
> +	xe_vm_destroy(fd, vm1);
> +	xe_vm_destroy(fd, vm2);
> +
> +	if (retained != 0)
> +		igt_skip("Unable to induce purge on this platform/config");
> +
> +}
> +
>   int igt_main()
>   {
>   	struct drm_xe_engine_class_instance *hwe;
> @@ -588,6 +696,12 @@ int igt_main()
>   			break;
>   		}
>   
> +	igt_subtest("per-vma-tracking")
> +		xe_for_each_engine(fd, hwe) {
> +			test_per_vma_tracking(fd, hwe);
> +			break;
> +		}
> +
>   	igt_fixture() {
>   		xe_device_put(fd);
>   		drm_close_driver(fd);