> -----Original Message-----
> From: Ma, WenwuX <wenwux...@intel.com>
> Sent: Friday, May 6, 2022 12:17 AM
> To: maxime.coque...@redhat.com; Xia, Chenbo <chenbo....@intel.com>;
> dev@dpdk.org
> Cc: Hu, Jiayu <jiayu...@intel.com>; Wang, Yinan <yinan.w...@intel.com>; He,
> Xingguang <xingguang...@intel.com>; Ma, WenwuX <wenwux...@intel.com>;
> sta...@dpdk.org
> Subject: [PATCH v2] vhost: fix deadlock when handling user messages
>
> In vhost_user_msg_handler(), if vhost message handling
> failed, we should check whether the queue is locked and
> release the lock before returning. Or, it will cause a
> deadlock later.
>
> Fixes: 7f31d4ea05ca ("vhost: fix lock on device readiness notification")
> Cc: sta...@dpdk.org
>
> Signed-off-by: Wenwu Ma <wenwux...@intel.com>
> ---
> lib/vhost/vhost_user.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
> index 1d390677fa..4baf969ee0 100644
> --- a/lib/vhost/vhost_user.c
> +++ b/lib/vhost/vhost_user.c
> @@ -2976,7 +2976,6 @@ vhost_user_msg_handler(int vid, int fd)
> return -1;
> }
>
> - ret = 0;
> request = ctx.msg.request.master;
> if (request > VHOST_USER_NONE && request < VHOST_USER_MAX &&
> vhost_message_str[request]) {
> @@ -3113,9 +3112,11 @@ vhost_user_msg_handler(int vid, int fd)
> send_vhost_reply(dev, fd, &ctx);
> } else if (ret == RTE_VHOST_MSG_RESULT_ERR) {
> VHOST_LOG_CONFIG(ERR, "(%s) vhost message handling failed.\n",
> dev->ifname);
> - return -1;
> + ret = -1;
> + goto unlock;
> }
>
> + ret = 0;
> for (i = 0; i < dev->nr_vring; i++) {
> struct vhost_virtqueue *vq = dev->virtqueue[i];
> bool cur_ready = vq_is_ready(dev, vq);
> @@ -3126,10 +3127,11 @@ vhost_user_msg_handler(int vid, int fd)
> }
> }
>
> +unlock:
> if (unlock_required)
> vhost_user_unlock_all_queue_pairs(dev);
>
> - if (!virtio_is_ready(dev))
> + if (ret != 0 || !virtio_is_ready(dev))
> goto out;
>
> /*
> @@ -3156,7 +3158,7 @@ vhost_user_msg_handler(int vid, int fd)
> }
>
> out:
> - return 0;
> + return ret;
> }
>
> static int process_slave_message_reply(struct virtio_net *dev,
> --
> 2.25.1
'vhost: fix deadlock when message handling failed' may be a better title.
Reviewed-by: Chenbo Xia <chenbo....@intel.com>
