+ Eli.
On Thu, Oct 1, 2020 at 2:02 PM Si-Wei Liu <si-wei....@oracle.com> wrote:
>
> A VM with mlx5 vDPA has below warnings while being reset:
>
> vhost VQ 0 ring restore failed: -1: Resource temporarily unavailable (11)
> vhost VQ 1 ring restore failed: -1: Resource temporarily unavailable (11)
>
> We should allow userspace emulating the virtio device be
> able to get to vq's avail_index, regardless of vDPA device
> status. Save the index that was last seen when virtq was
> stopped, so that userspace doesn't complain.
>
> Signed-off-by: Si-Wei Liu <si-wei....@oracle.com>
> ---
> drivers/vdpa/mlx5/net/mlx5_vnet.c | 20 ++++++++++++++------
> 1 file changed, 14 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> index 70676a6..74264e59 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> @@ -1133,15 +1133,17 @@ static void suspend_vq(struct mlx5_vdpa_net *ndev,
> struct mlx5_vdpa_virtqueue *m
> if (!mvq->initialized)
> return;
>
> - if (query_virtqueue(ndev, mvq, &attr)) {
> - mlx5_vdpa_warn(&ndev->mvdev, "failed to query virtqueue\n");
> - return;
> - }
> if (mvq->fw_state != MLX5_VIRTIO_NET_Q_OBJECT_STATE_RDY)
> return;
>
> if (modify_virtqueue(ndev, mvq,
> MLX5_VIRTIO_NET_Q_OBJECT_STATE_SUSPEND))
> mlx5_vdpa_warn(&ndev->mvdev, "modify to suspend failed\n");
> +
> + if (query_virtqueue(ndev, mvq, &attr)) {
> + mlx5_vdpa_warn(&ndev->mvdev, "failed to query virtqueue\n");
> + return;
> + }
> + mvq->avail_idx = attr.available_index;
> }
>
> static void suspend_vqs(struct mlx5_vdpa_net *ndev)
> @@ -1411,8 +1413,14 @@ static int mlx5_vdpa_get_vq_state(struct vdpa_device
> *vdev, u16 idx, struct vdpa
> struct mlx5_virtq_attr attr;
> int err;
>
> - if (!mvq->initialized)
> - return -EAGAIN;
> + /* If the virtq object was destroyed, use the value saved at
> + * the last minute of suspend_vq. This caters for userspace
> + * that cares about emulating the index after vq is stopped.
> + */
> + if (!mvq->initialized) {
> + state->avail_index = mvq->avail_idx;
> + return 0;
> + }
>
> err = query_virtqueue(ndev, mvq, &attr);
> if (err) {
> --
> 1.8.3.1
>
