[net,2/3] vhost_net: keep private_data and rx_ring synced
diff mbox series

Message ID 1520578234-5565-3-git-send-email-jasowang@redhat.com
State New, archived
Headers show
Series
  • Several fixes for vhost_net ptr_ring usage
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Commit Message

Jason Wang March 9, 2018, 6:50 a.m. UTC
We get pointer ring from the exported sock, this means we should keep
rx_ring and vq->private synced during both vq stop and backend set,
otherwise we may see stale rx_ring.

Fixes: c67df11f6e480 ("vhost_net: try batch dequing from skb array")
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/vhost/net.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

Michael S. Tsirkin March 9, 2018, 4:56 p.m. UTC | #1
On Fri, Mar 09, 2018 at 02:50:33PM +0800, Jason Wang wrote:
> We get pointer ring from the exported sock, this means we should keep
> rx_ring and vq->private synced during both vq stop and backend set,
> otherwise we may see stale rx_ring.
> 
> Fixes: c67df11f6e480 ("vhost_net: try batch dequing from skb array")
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>

Acked-by: Michael S. Tsirkin <mst@redhat.com>

> ---
>  drivers/vhost/net.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> index 60f1080..efb9306 100644
> --- a/drivers/vhost/net.c
> +++ b/drivers/vhost/net.c
> @@ -973,6 +973,7 @@ static struct socket *vhost_net_stop_vq(struct vhost_net *n,
>  	vhost_net_disable_vq(n, vq);
>  	vq->private_data = NULL;
>  	vhost_net_buf_unproduce(nvq);
> +	nvq->rx_ring = NULL;
>  	mutex_unlock(&vq->mutex);
>  	return sock;
>  }
> @@ -1162,14 +1163,14 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
>  		vhost_net_disable_vq(n, vq);
>  		vq->private_data = sock;
>  		vhost_net_buf_unproduce(nvq);
> -		if (index == VHOST_NET_VQ_RX)
> -			nvq->rx_ring = get_tap_ptr_ring(fd);
>  		r = vhost_vq_init_access(vq);
>  		if (r)
>  			goto err_used;
>  		r = vhost_net_enable_vq(n, vq);
>  		if (r)
>  			goto err_used;
> +		if (index == VHOST_NET_VQ_RX)
> +			nvq->rx_ring = get_tap_ptr_ring(fd);
>  
>  		oldubufs = nvq->ubufs;
>  		nvq->ubufs = ubufs;
> -- 
> 2.7.4

Patch
diff mbox series

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 60f1080..efb9306 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -973,6 +973,7 @@  static struct socket *vhost_net_stop_vq(struct vhost_net *n,
 	vhost_net_disable_vq(n, vq);
 	vq->private_data = NULL;
 	vhost_net_buf_unproduce(nvq);
+	nvq->rx_ring = NULL;
 	mutex_unlock(&vq->mutex);
 	return sock;
 }
@@ -1162,14 +1163,14 @@  static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
 		vhost_net_disable_vq(n, vq);
 		vq->private_data = sock;
 		vhost_net_buf_unproduce(nvq);
-		if (index == VHOST_NET_VQ_RX)
-			nvq->rx_ring = get_tap_ptr_ring(fd);
 		r = vhost_vq_init_access(vq);
 		if (r)
 			goto err_used;
 		r = vhost_net_enable_vq(n, vq);
 		if (r)
 			goto err_used;
+		if (index == VHOST_NET_VQ_RX)
+			nvq->rx_ring = get_tap_ptr_ring(fd);
 
 		oldubufs = nvq->ubufs;
 		nvq->ubufs = ubufs;