diff options
| author | Aaron Conole | 2016-06-03 16:57:12 -0400 |
|---|---|---|
| committer | David S. Miller | 2016-06-06 21:08:49 -0400 |
| commit | 14de9d114a82a564b94388c95af79a701dc93134 (patch) | |
| tree | 0383dc33ea97f87ab15be125f8f702b009d76923 | |
| parent | 3d9dc408fa6abf8dd1ea39e243e565891004a6f9 (diff) | |
virtio-net: Add initial MTU advice feature
This commit adds the feature bit and associated mtu device entry for the
virtio network device. When a virtio device comes up, it checks the
feature bit for the VIRTIO_NET_F_MTU feature. If such feature bit is
enabled, the driver will read the advised MTU and use it as the initial
value.
Signed-off-by: Aaron Conole <aconole@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/virtio_net.c | 10 | ||||
| -rw-r--r-- | include/uapi/linux/virtio_net.h | 3 |
2 files changed, 13 insertions, 0 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index e0638e556fe7..192f321247b9 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1780,6 +1780,7 @@ static int virtnet_probe(struct virtio_device *vdev) struct net_device *dev; struct virtnet_info *vi; u16 max_queue_pairs; + int mtu; if (!vdev->config->get) { dev_err(&vdev->dev, "%s failure: config access disabled\n", @@ -1896,6 +1897,14 @@ 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)) { + mtu = virtio_cread16(vdev, + offsetof(struct virtio_net_config, + mtu)); + if (virtnet_change_mtu(dev, mtu)) + __virtio_clear_bit(vdev, VIRTIO_NET_F_MTU); + } + if (vi->any_header_sg) dev->needed_headroom = vi->hdr_len; @@ -2067,6 +2076,7 @@ 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 = { diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h index ec32293a00db..1ab4ea6ec847 100644 --- a/include/uapi/linux/virtio_net.h +++ b/include/uapi/linux/virtio_net.h @@ -55,6 +55,7 @@ #define VIRTIO_NET_F_MQ 22 /* Device supports Receive Flow * Steering */ #define VIRTIO_NET_F_CTRL_MAC_ADDR 23 /* Set MAC address */ +#define VIRTIO_NET_F_MTU 25 /* Initial MTU advice */ #ifndef VIRTIO_NET_NO_LEGACY #define VIRTIO_NET_F_GSO 6 /* Host handles pkts w/ any GSO type */ @@ -73,6 +74,8 @@ struct virtio_net_config { * Legal values are between 1 and 0x8000 */ __u16 max_virtqueue_pairs; + /* Default maximum transmit unit advice */ + __u16 mtu; } __attribute__((packed)); /* |