Re: [PATCH 4/4] xe: populate buffers before exporting them.

["Thomas Hellström" <thomas.hellstrom@linux.intel.com>]

On Thu, 2025-09-04 at 12:16 +1000, Dave Airlie wrote:
> From: Dave Airlie <airlied@redhat.com>
> 
> Before exporting a buffer, make sure it has been populated with
> pages at least once.
> 
> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> Signed-off-by: Dave Airlie <airlied@redhat.com>

Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>

> ---
>  drivers/gpu/drm/xe/xe_dma_buf.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_dma_buf.c
> b/drivers/gpu/drm/xe/xe_dma_buf.c
> index 346f857f3837..71b70e17bddd 100644
> --- a/drivers/gpu/drm/xe/xe_dma_buf.c
> +++ b/drivers/gpu/drm/xe/xe_dma_buf.c
> @@ -191,10 +191,22 @@ struct dma_buf *xe_gem_prime_export(struct
> drm_gem_object *obj, int flags)
>  {
>  	struct xe_bo *bo = gem_to_xe_bo(obj);
>  	struct dma_buf *buf;
> +	struct ttm_operation_ctx ctx = {
> +		.interruptible = true,
> +		.no_wait_gpu = true,
> +		/* We opt to avoid OOM on system pages allocations
> */
> +		.gfp_retry_mayfail = true,
> +		.allow_res_evict = false,
> +	};
> +	int ret;
>  
>  	if (bo->vm)
>  		return ERR_PTR(-EPERM);
>  
> +	ret = ttm_bo_setup_export(&bo->ttm, &ctx);
> +	if (ret)
> +		return ERR_PTR(ret);
> +
>  	buf = drm_gem_prime_export(obj, flags);
>  	if (!IS_ERR(buf))
>  		buf->ops = &xe_dmabuf_ops;