Re: [PATCH v7 26/26] virtio_net: support set_ringparam

Support set_ringparam based on virtio queue reset.

The rx,tx_pending required to be passed must be power of 2.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
  drivers/net/virtio_net.c | 47 ++++++++++++++++++++++++++++++++++++++++
  1 file changed, 47 insertions(+)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index f1bdc6ce21c3..1fa2d632a994 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c

@@ -2290,6 +2290,52 @@ 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 > virtqueue_get_vring_max_size(vi->rq[0].vq))
+		return -EINVAL;
+
+	if (ring->tx_pending > virtqueue_get_vring_max_size(vi->sq[0].vq))
+		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_vq_reset(vi, sq, ring->tx_pending);
+			if (err)
+				return err;
+		}
+
+		if (ring->rx_pending != rx_pending) {
+			err = virtnet_rx_vq_reset(vi, rq, ring->rx_pending);
+			if (err)
+				return err;
+		}
+	}
+
+	return 0;
+}
  
  static void virtnet_get_drvinfo(struct net_device *dev,
  				struct ethtool_drvinfo *info)

@@ -2523,6 +2569,7 @@ 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,