Re: [PATCH v2 03/10] vhost-scsi: Fix vhost_scsi_send_status()

[Jason Wang]

On Tue, Mar 18, 2025 at 7:52 AM Dongli Zhang <dongli.zhang@xxxxxxxxxx> wrote:
>
> Although the support of VIRTIO_F_ANY_LAYOUT + VIRTIO_F_VERSION_1 was
> signaled by the commit 664ed90e621c ("vhost/scsi: Set
> VIRTIO_F_ANY_LAYOUT + VIRTIO_F_VERSION_1 feature bits"),
> vhost_scsi_send_bad_target() still assumes the response in a single
> descriptor.
>
> Similar issue in vhost_scsi_send_bad_target() has been fixed in previous
> commit.
>
> Fixes: 3ca51662f818 ("vhost-scsi: Add better resource allocation failure handling")

And

6dd88fd59da84631b5fe5c8176931c38cfa3b265 ("vhost-scsi: unbreak any
layout for response")

> Signed-off-by: Dongli Zhang <dongli.zhang@xxxxxxxxxx>
> ---
> Changed since v1:
>   - New patch to fix vhost_scsi_send_status().
>
>  drivers/vhost/scsi.c | 18 +++++++++++-------
>  1 file changed, 11 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
> index 59d907b94c5e..26bcf3a7f70c 100644
> --- a/drivers/vhost/scsi.c
> +++ b/drivers/vhost/scsi.c
> @@ -999,18 +999,22 @@ static void vhost_scsi_target_queue_cmd(struct vhost_scsi_nexus *nexus,
>
>  static void
>  vhost_scsi_send_status(struct vhost_scsi *vs, struct vhost_virtqueue *vq,
> -                      int head, unsigned int out, u8 status)
> +                      struct vhost_scsi_ctx *vc, u8 status)
>  {
> -       struct virtio_scsi_cmd_resp __user *resp;
>         struct virtio_scsi_cmd_resp rsp;
> +       struct iov_iter iov_iter;
>         int ret;
>
>         memset(&rsp, 0, sizeof(rsp));
>         rsp.status = status;
> -       resp = vq->iov[out].iov_base;
> -       ret = __copy_to_user(resp, &rsp, sizeof(rsp));
> -       if (!ret)
> -               vhost_add_used_and_signal(&vs->dev, vq, head, 0);
> +
> +       iov_iter_init(&iov_iter, ITER_DEST, &vq->iov[vc->out], vc->in,
> +                     sizeof(rsp));
> +
> +       ret = copy_to_iter(&rsp, sizeof(rsp), &iov_iter);
> +
> +       if (likely(ret == sizeof(rsp)))
> +               vhost_add_used_and_signal(&vs->dev, vq, vc->head, 0);
>         else
>                 pr_err("Faulted on virtio_scsi_cmd_resp\n");
>  }
> @@ -1420,7 +1424,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
>                 else if (ret == -EIO)
>                         vhost_scsi_send_bad_target(vs, vq, &vc, TYPE_IO_CMD);
>                 else if (ret == -ENOMEM)
> -                       vhost_scsi_send_status(vs, vq, vc.head, vc.out,
> +                       vhost_scsi_send_status(vs, vq, &vc,
>                                                SAM_STAT_TASK_SET_FULL);
>         } while (likely(!vhost_exceeds_weight(vq, ++c, 0)));
>  out:
> --
> 2.39.3
>

Acked-by: Jason Wang <jasowang@xxxxxxxxxx>

Thanks