Re: [PATCH] virtio_net: enable big packets for large MTU values
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2017-03-29 16:13:38
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On Wed, Mar 29, 2017 at 03:38:09PM +0300, Michael S. Tsirkin wrote:
If one enables e.g. jumbo frames without mergeable buffers, packets won't fit in 1500 byte buffers we use. Switch to big packet mode instead. TODO: make sizing more exact, possibly extend small packet mode to use larger pages. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Fixes: 14de9d114a82 ("virtio-net: Add initial MTU advice feature")
quoted hunk ↗ jump to hunk
--- drivers/net/virtio_net.c | 4 ++++ 1 file changed, 4 insertions(+)diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index e0fb3707..9dc31dc 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c@@ -2428,6 +2428,10 @@ static int virtnet_probe(struct virtio_device *vdev) dev->mtu = mtu; dev->max_mtu = mtu; } + + /* TODO: size buffers correctly in this case. */ + if (dev->mtu > ETH_DATA_LEN) + vi->big_packets = true; } if (vi->any_header_sg)-- MST