Re: [PATCH] drm/amdgpu/userq: serialize queue map against GPU reset

On Mon, Aug 3, 2026 at 6:13=E2=80=AFAM Jesse Zhang <[email protected]> wr=
ote:
>
> Creating a user queue can race with a GPU reset. While recovery holds
> reset_domain->sem for write, MES is unresponsive, so the ADD_QUEUE from
> amdgpu_userq_map_helper() times out (-110) and an otherwise valid queue
> create fails:
>
>   amdgpu: MES(0) failed to respond to msg=3DADD_QUEUE
>   [drm:mes_userq_map [amdgpu]] *ERROR* Failed to map queue in HW, err (-1=
10)
>   amdgpu: [drm] *ERROR* ... Failed to map Queue
>   amdgpu: [drm] *ERROR* ... Failed to create usermode queue
>
> Take reset_domain->sem for read around the map so it runs only once MES
> is back up. This mirrors amdgpu_userq_cleanup() and honors the
> userq_mutex -> reset_domain->sem order; the reset path never takes
> userq_mutex, so there is no deadlock.

Reviewed-by: Alex Deucher <[email protected]>

>
> Signed-off-by: Jesse Zhang <[email protected]>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c b/drivers/gpu/drm/=
amd/amdgpu/amdgpu_userq.c
> index 652599f08990..770635ab5298 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c
> @@ -745,7 +745,12 @@ amdgpu_userq_create(struct drm_file *filp, union drm=
_amdgpu_userq *args)
>         if (!adev->userq_halt_for_enforce_isolation ||
>             ((queue->queue_type !=3D AMDGPU_HW_IP_GFX) &&
>              (queue->queue_type !=3D AMDGPU_HW_IP_COMPUTE))) {
> +               /* Serialize the map against an in-progress GPU reset (ME=
S is
> +                * unresponsive during recovery), matching amdgpu_userq_c=
leanup().
> +                */
> +               down_read(&adev->reset_domain->sem);
>                 r =3D amdgpu_userq_map_helper(queue);
> +               up_read(&adev->reset_domain->sem);
>                 if (r) {
>                         drm_file_err(uq_mgr->file, "Failed to map Queue\n=
");
>                         trace_amdgpu_userq_create_end(queue, r);
> --
> 2.49.0
>