Re: [V2] drm/xe: Skip clearing purged page-table BOs

["Ghimiray, Himal Prasad" <himal.prasad.ghimiray@intel.com>]

On 07-09-2026 21:07, Tejas Upadhyay wrote:
> VRAM page offlining can clear a page-table BO's vmap before VM teardown
> calls xe_pt_clear(). Check for a purged BO under its dma-resv lock before
> writing to the mapping.
> 
> v2(Sashiko):
> - Fix lock ordering
> 
> Signed-off-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
> ---
>   drivers/gpu/drm/xe/xe_pt.c | 6 ++++--
>   drivers/gpu/drm/xe/xe_vm.c | 8 +++++---
>   2 files changed, 9 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_pt.c b/drivers/gpu/drm/xe/xe_pt.c
> index 5d990c1c3740..a9b9cd7ac2c8 100644
> --- a/drivers/gpu/drm/xe/xe_pt.c
> +++ b/drivers/gpu/drm/xe/xe_pt.c
> @@ -236,9 +236,11 @@ void xe_pt_destroy(struct xe_pt *pt, u32 flags, struct llist_head *deferred)
>    */
>   void xe_pt_clear(struct xe_device *xe, struct xe_pt *pt)
>   {
> -	struct iosys_map *map = &pt->bo->vmap;
> +	struct xe_bo *bo = pt->bo;
>   
> -	xe_map_memset(xe, map, 0, 0, SZ_4K);
> +	xe_bo_assert_held(bo);
> +	if (!xe_bo_is_purged(bo))
> +		xe_map_memset(xe, &bo->vmap, 0, 0, SZ_4K);
>   }
>   
>   /**
> diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
> index 9e71567b27cc..e77ff3cf3ca3 100644
> --- a/drivers/gpu/drm/xe/xe_vm.c
> +++ b/drivers/gpu/drm/xe/xe_vm.c
> @@ -1876,10 +1876,13 @@ static void xe_vm_close(struct xe_vm *vm)
>   	bound = drm_dev_enter(&xe->drm, &idx);
>   
>   	down_write(&vm->lock);
> +	xe_vm_lock(vm, false);
> +
>   	if (xe_vm_in_fault_mode(vm))
>   		xe_svm_notifier_lock(vm);
> -
>   	vm->size = 0;
> +	if (xe_vm_in_fault_mode(vm))
> +		xe_svm_notifier_unlock(vm);
>   
>   	if (!((vm->flags & XE_VM_FLAG_MIGRATION))) {
>   		struct xe_tile *tile;
> @@ -1901,8 +1904,7 @@ static void xe_vm_close(struct xe_vm *vm)
>   		}
>   	}
>   
> -	if (xe_vm_in_fault_mode(vm))
> -		xe_svm_notifier_unlock(vm);
> +	xe_vm_unlock(vm);
>   	up_write(&vm->lock);

LGTM
Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>

>   
>   	if (bound)