[PATCH -next 2/2] virtio_net: Read the advised MTU
From: Aaron Conole <aconole@redhat.com>
Date: 2016-06-02 15:46:45
Also in:
lkml, virtualization
Subsystem:
networking drivers, the rest, virtio net driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, "Michael S. Tsirkin", Jason Wang
This patch checks the feature bit for the VIRTIO_NET_F_MTU feature. If it exists, read the advised MTU and use it. No proper error handling is provided for the case where a user changes the negotiated MTU. A future commit will add proper error handling. Instead, a warning is emitted if the guest changes the device MTU after previously being given advice. Signed-off-by: Aaron Conole <aconole@redhat.com> --- drivers/net/virtio_net.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index e0638e5..ef5ee01 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c@@ -1896,6 +1896,12 @@ static int virtnet_probe(struct virtio_device *vdev) if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) vi->has_cvq = true; + if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) { + dev->mtu = virtio_cread16(vdev, + offsetof(struct virtio_net_config, + mtu)); + } + if (vi->any_header_sg) dev->needed_headroom = vi->hdr_len;
@@ -2067,6 +2073,7 @@ static unsigned int features[] = { VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, VIRTIO_NET_F_CTRL_MAC_ADDR, VIRTIO_F_ANY_LAYOUT, + VIRTIO_NET_F_MTU, }; static struct virtio_driver virtio_net_driver = {
--
2.5.5