Re: [dpdk-dev] [PATCH v1] vhost: add vq status check in async enqueue poll

["Xia, Chenbo" <chenbo.xia@intel.com>]

> -----Original Message-----
> From: Fu, Patrick <patrick.fu@intel.com>
> Sent: Thursday, July 16, 2020 11:30 PM
> To: dev@dpdk.org; maxime.coquelin@redhat.com; Xia, Chenbo
> <chenbo.xia@intel.com>
> Cc: Fu, Patrick <patrick.fu@intel.com>
> Subject: [PATCH v1] vhost: add vq status check in async enqueue poll
> 
> From: Patrick Fu <patrick.fu@intel.com>
> 
> Vring should not be touched if vq is disabled. This patch adds the vq status check
> in async enqueue polling to avoid accessing to a disabled queue.
> 
> Fixes: cd6760da1076 ("vhost: introduce async enqueue for split ring")
> 
> Signed-off-by: Patrick Fu <patrick.fu@intel.com>
> ---
>  lib/librte_vhost/virtio_net.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c index
> 1d0be3dd4..b197d76d3 100644
> --- a/lib/librte_vhost/virtio_net.c
> +++ b/lib/librte_vhost/virtio_net.c
> @@ -1686,9 +1686,11 @@ uint16_t rte_vhost_poll_enqueue_completed(int vid,
> uint16_t queue_id,
> 
>  	if (n_pkts_put) {
>  		vq->async_pkts_inflight_n -= n_pkts_put;
> -		__atomic_add_fetch(&vq->used->idx, n_descs,
> __ATOMIC_RELEASE);
> -
> -		vhost_vring_call_split(dev, vq);
> +		if (likely(vq->enabled && vq->access_ok)) {
> +			__atomic_add_fetch(&vq->used->idx,
> +					n_descs, __ATOMIC_RELEASE);
> +			vhost_vring_call_split(dev, vq);
> +		}
>  	}
> 
>  	if (start_idx + n_pkts_put <= vq_size) {
> --
> 2.18.4

Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>