On Sat, Nov 17, 2012 at 12:35:29AM +0000, Ben Hutchings wrote:

On Tue, 2012-11-13 at 08:40 +0200, Michael S. Tsirkin wrote:

quoted

On Mon, Nov 05, 2012 at 11:38:39AM +1030, Rusty Russell wrote:

quoted

quoted

@@ -924,11 +1032,10 @@ static void virtnet_get_ringparam(struct net_device *dev,
 {
 	struct virtnet_info *vi = netdev_priv(dev);
 
-	ring->rx_max_pending = virtqueue_get_vring_size(vi->rvq);
-	ring->tx_max_pending = virtqueue_get_vring_size(vi->svq);
+	ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
+	ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
 	ring->rx_pending = ring->rx_max_pending;
 	ring->tx_pending = ring->tx_max_pending;
-
 }

This assumes all vqs are the same size.  I think this should probably
check: for mq mode, use the first vq, otherewise use the 0th.

For rx_pending/tx_pending I think what is required here is the
actual number of outstanding buffers.
Dave, Eric - right?

So this should be the total over all rings and to be useful,
rx_max_pending/tx_max_pending should be the total too.

So far as I know, all current implementations use the number of
descriptors per ring here. virtio_net should be consistent with this.

Ben.

Problem is, it could in theory be different between rings. I guess we
could use the maximum.

What's the right thing to do for rx_pending - I am guessing
we want the current outstanding packets right?

quoted

quoted

For bonus points, check this assertion at probe time.

Looks like we can easily support different queues too.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.