Re: [PATCH V19 06/15] drm/xe: Guard teardown paths against purged BOs

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

On 31-08-2026 12:19, Tejas Upadhyay wrote:
> VRAM page offlining can purge BOs that are still referenced by page
> tables, exec queues, and DMA-buf exports. Add xe_bo_is_purged()
> guards in the teardown paths to prevent unpinning or mapping an
> already-purged BO:
> 
> - xe_bo_unpin_map_no_vm(): skip unpin if purged
> - xe_dma_buf_map(): return -ENOENT early if purged
> - xe_exec_queue_update_run_ticks(): skip LRC timestamp read if purged
> - xe_pt_destroy(): skip unpin if purged
> 
> v4(Sashiko):
> - Move bo purge check in xe_bo_unpin() to handle all instances
> v3(Sashiko):
> - Remove dma_resv is already held
> v2(Himal):
> - take dma_resv lock before calling xe_bo_is_purged()
> 

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

> Signed-off-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
> ---
>   drivers/gpu/drm/xe/xe_bo.c         | 3 +++
>   drivers/gpu/drm/xe/xe_dma_buf.c    | 3 +++
>   drivers/gpu/drm/xe/xe_exec_queue.c | 8 ++++++--
>   3 files changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
> index c255327669da..b162753cebb7 100644
> --- a/drivers/gpu/drm/xe/xe_bo.c
> +++ b/drivers/gpu/drm/xe/xe_bo.c
> @@ -3267,6 +3267,9 @@ void xe_bo_unpin(struct xe_bo *bo)
>   	struct ttm_place *place = &bo->placements[0];
>   	struct xe_device *xe = xe_bo_device(bo);
>   
> +	if (xe_bo_is_purged(bo))
> +		return;
> +
>   	xe_assert(xe, !bo->ttm.base.import_attach);
>   	xe_assert(xe, xe_bo_is_pinned(bo));
>   
> diff --git a/drivers/gpu/drm/xe/xe_dma_buf.c b/drivers/gpu/drm/xe/xe_dma_buf.c
> index bf0728838ead..5d9f1cd24b7f 100644
> --- a/drivers/gpu/drm/xe/xe_dma_buf.c
> +++ b/drivers/gpu/drm/xe/xe_dma_buf.c
> @@ -104,6 +104,9 @@ static struct sg_table *xe_dma_buf_map(struct dma_buf_attachment *attach,
>   	struct sg_table *sgt;
>   	int r = 0;
>   
> +	if (xe_bo_is_purged(bo))
> +		return ERR_PTR(-ENOENT);
> +
>   	if (!attach->peer2peer && !xe_bo_can_migrate(bo, XE_PL_TT))
>   		return ERR_PTR(-EOPNOTSUPP);
>   
> diff --git a/drivers/gpu/drm/xe/xe_exec_queue.c b/drivers/gpu/drm/xe/xe_exec_queue.c
> index 91ed6c0fac84..91e4f3cb5617 100644
> --- a/drivers/gpu/drm/xe/xe_exec_queue.c
> +++ b/drivers/gpu/drm/xe/xe_exec_queue.c
> @@ -1572,8 +1572,12 @@ void xe_exec_queue_update_run_ticks(struct xe_exec_queue *q)
>   	 * errors.
>   	 */
>   	lrc = q->lrc[0];
> -	new_ts = xe_lrc_update_timestamp(lrc, &old_ts);
> -	q->xef->run_ticks[q->class] += (new_ts - old_ts) * q->width;
> +	xe_bo_lock(lrc->bo, false);
> +	if (!xe_bo_is_purged(lrc->bo)) {
> +		new_ts = xe_lrc_update_timestamp(lrc, &old_ts);
> +		q->xef->run_ticks[q->class] += (new_ts - old_ts) * q->width;
> +	}
> +	xe_bo_unlock(lrc->bo);
>   
>   	drm_dev_exit(idx);
>   }