virtio_net: support set_ringparam

Support set_ringparam based on virtio queue reset.

Users can use ethtool -G eth0 <ring_num> to modify the ring size of
virtio-net.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220801063902.129329-43-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 6aa0871..16783ed 100644 (file)
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2363,6 +2363,53 @@ static void virtnet_get_ringparam(struct net_device *dev,
        ring->tx_pending = virtqueue_get_vring_size(vi->sq[0].vq);
 }
 
+static int virtnet_set_ringparam(struct net_device *dev,
+                                struct ethtool_ringparam *ring,
+                                struct kernel_ethtool_ringparam *kernel_ring,
+                                struct netlink_ext_ack *extack)
+{
+       struct virtnet_info *vi = netdev_priv(dev);
+       u32 rx_pending, tx_pending;
+       struct receive_queue *rq;
+       struct send_queue *sq;
+       int i, err;
+
+       if (ring->rx_mini_pending || ring->rx_jumbo_pending)
+               return -EINVAL;
+
+       rx_pending = virtqueue_get_vring_size(vi->rq[0].vq);
+       tx_pending = virtqueue_get_vring_size(vi->sq[0].vq);
+
+       if (ring->rx_pending == rx_pending &&
+           ring->tx_pending == tx_pending)
+               return 0;
+
+       if (ring->rx_pending > vi->rq[0].vq->num_max)
+               return -EINVAL;
+
+       if (ring->tx_pending > vi->sq[0].vq->num_max)
+               return -EINVAL;
+
+       for (i = 0; i < vi->max_queue_pairs; i++) {
+               rq = vi->rq + i;
+               sq = vi->sq + i;
+
+               if (ring->tx_pending != tx_pending) {
+                       err = virtnet_tx_resize(vi, sq, ring->tx_pending);
+                       if (err)
+                               return err;
+               }
+
+               if (ring->rx_pending != rx_pending) {
+                       err = virtnet_rx_resize(vi, rq, ring->rx_pending);
+                       if (err)
+                               return err;
+               }
+       }
+
+       return 0;
+}
+
 static bool virtnet_commit_rss_command(struct virtnet_info *vi)
 {
        struct net_device *dev = vi->dev;
@@ -2850,6 +2897,7 @@ static const struct ethtool_ops virtnet_ethtool_ops = {
        .get_drvinfo = virtnet_get_drvinfo,
        .get_link = ethtool_op_get_link,
        .get_ringparam = virtnet_get_ringparam,
+       .set_ringparam = virtnet_set_ringparam,
        .get_strings = virtnet_get_strings,
        .get_sset_count = virtnet_get_sset_count,
        .get_ethtool_stats = virtnet_get_ethtool_stats,