From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: [PATCH] virtio_net: enable big packets for large MTU values Date: Wed, 29 Mar 2017 15:38:09 +0300 Message-ID: <1490791079-22108-1-git-send-email-mst@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, virtualization@lists.linux-foundation.org To: linux-kernel@vger.kernel.org Return-path: Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org List-Id: netdev.vger.kernel.org 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 --- 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