virtio_net: ensure netdev_tx_reset_queue is called on tx ring resize

commit 1480f0f61b675567ca5d0943d6ef2e39172dcafd upstream.

virtnet_tx_resize() flushes remaining tx skbs, requiring DQL counters to
be reset when flushing has actually occurred. Add
virtnet_sq_free_unused_buf_done() as a callback for virtqueue_reset() to
handle this.

Fixes: c8bd1f7f3e61 ("virtio_net: add support for Byte Queue Limits")
Cc: <stable@vger.kernel.org> # v6.11+
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 37acc82be45d4c01f5a592b67eb097cb221754c9..60027b439021b8f48f140ee83d93e92d5770f6a1 100644 (file)
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -502,6 +502,7 @@ struct virtio_net_common_hdr {
 };
 
 static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf);
+static void virtnet_sq_free_unused_buf_done(struct virtqueue *vq);
 static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
                               struct net_device *dev,
                               unsigned int *xdp_xmit,
@@ -3228,7 +3229,8 @@ static int virtnet_tx_resize(struct virtnet_info *vi, struct send_queue *sq,
 
        virtnet_tx_pause(vi, sq);
 
-       err = virtqueue_resize(sq->vq, ring_num, virtnet_sq_free_unused_buf, NULL);
+       err = virtqueue_resize(sq->vq, ring_num, virtnet_sq_free_unused_buf,
+                              virtnet_sq_free_unused_buf_done);
        if (err)
                netdev_err(vi->dev, "resize tx fail: tx queue index: %d err: %d\n", qindex, err);
 
@@ -5996,6 +5998,14 @@ static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf)
                xdp_return_frame(ptr_to_xdp(buf));
 }
 
+static void virtnet_sq_free_unused_buf_done(struct virtqueue *vq)
+{
+       struct virtnet_info *vi = vq->vdev->priv;
+       int i = vq2txq(vq);
+
+       netdev_tx_reset_queue(netdev_get_tx_queue(vi->dev, i));
+}
+
 static void free_unused_bufs(struct virtnet_info *vi)
 {
        void *buf;