Re: [PATCH] vhost-vdpa: propagate set_map error to caller

On Thu, Jul 16, 2026 at 5:02 AM Weimin Xiong <[email protected]> wrote:
>
> From: xiongweimin <[email protected]>
>
> The return value of ops->set_map() is currently ignored when handling
> VHOST_IOTLB_BATCH_END. If the backend fails to program the IOTLB,
> the VMM incorrectly believes the operation succeeded and may continue
> with stale or incorrect mappings.
>
> Save and propagate the error from ops->set_map() in BATCH_END.
>
> Signed-off-by: xiongweimin <[email protected]>
> ---
>  drivers/vhost/vdpa.c | 6 +++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
> index bb96b1aa5..ffbb10a92 100644
> --- a/drivers/vhost/vdpa.c
> +++ b/drivers/vhost/vdpa.c
> @@ -1297,8 +1297,10 @@ static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev, u32 asid,
>                 v->in_batch = true;
>                 break;
>         case VHOST_IOTLB_BATCH_END:
> -               if (v->in_batch && ops->set_map)
> -                       ops->set_map(vdpa, asid, iotlb);
> +               if (v->in_batch && ops->set_map) {
> +                       r = ops->set_map(vdpa, asid, iotlb);
> +                       break;
> +               }
>                 v->in_batch = false;

Maybe this needs to be discussed, but v->in_batch should be set to
false even in failure case.

>                 break;
>         default:
> --
> 2.39.3
>