[PATCH v2] vhost: cleanup resubmit info before inflight setup

[Maxime Coquelin]

On 4/26/24 13:09, Haoqian He wrote:
> This patch fixes a potential VM hang bug when the VM reboots after
> vhost live recovery due to missing cleanup virtqueue resubmit info.
> 
> Specifically, if inflight IO that should be resubmitted during
> the latest vhost reconnection has not been submitted yet while
> VM rebooting, so GET_VRING_BASE would not wait for the inflight
> IO, at this time the resubmit info has been.  When the VM restarts,
> SET_VRING_KICK will resubmit the inflight IO (If resubmit info
> is not null, function set_vring_kick will return without updating
> resubmit info).
> 
> It’s an error, any stale inflight IO should not be resubmitted
> after the VM restart.
> 
> The solution is to clean up virtqueue resubmit info when function
> set_inflight_fd before function set_vring_kick.
> 
> Fixes: ad0a4ae491fe ("vhost: checkout resubmit inflight information")
> Cc: stable at dpdk.org
> 
> Signed-off-by: Haoqian He <haoqian.he at smartx.com>
> ---
> v2: rewrite the commit message.
> 
>   lib/vhost/vhost_user.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
> index 414192500e..7c54afc5fb 100644
> --- a/lib/vhost/vhost_user.c
> +++ b/lib/vhost/vhost_user.c
> @@ -1871,6 +1871,7 @@ vhost_user_set_inflight_fd(struct virtio_net **pdev,
>   		if (!vq)
>   			continue;
>   
> +		cleanup_vq_inflight(dev, vq);
>   		if (vq_is_packed(dev)) {
>   			vq->inflight_packed = addr;
>   			vq->inflight_packed->desc_num = queue_size;

Reviewed-by: Maxime Coquelin <maxime.coquelin at redhat.com>

Thanks,
Maxime