Re: [PATCH v11 05/12] vdpa: document set_group_asid thread safety

From: Michael S. Tsirkin

Date: Sat Jan 10 2026 - 18:48:47 EST


On Fri, Jan 09, 2026 at 04:24:23PM +0100, Eugenio Pérez wrote:
> Document that the function races with the check of DRIVER_OK.
>
> Signed-off-by: Eugenio Pérez <eperezma@xxxxxxxxxx>
> ---
> Requested at
> https://lore.kernel.org/lkml/CACGkMEvXdV4ukZE6xhLL0sSN70G=AWVQgpRnH98Fr4btzMkK9g@xxxxxxxxxxxxxx/
> ---
> include/linux/vdpa.h | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
> index 4cf21d6e9cfd..cd1b1f1321b9 100644
> --- a/include/linux/vdpa.h
> +++ b/include/linux/vdpa.h
> @@ -312,7 +312,9 @@ struct vdpa_map_file {
> * @idx: virtqueue index
> * Returns the affinity mask
> * @set_group_asid: Set address space identifier for a
> - * virtqueue group (optional)
> + * virtqueue group (optional). It's not thread
> + * safe to call this function concurrently with
> + * set_status.

Let's be explicit about what to do.
"Caller must prevent this from being executed concurrently with
set_status"?


> * @vdev: vdpa device
> * @group: virtqueue group
> * @asid: address space id for this group
> --
> 2.52.0