Commit 9f4d26d0 authored by Mark McLoughlin's avatar Mark McLoughlin Committed by David S. Miller
Browse files

virtio_net: add link status handling 



Allow the host to inform us that the link is down by adding
a VIRTIO_NET_F_STATUS which indicates that device status is
available in virtio_net config.

This is currently useful for simulating link down conditions
(e.g. using proposed qemu 'set_link' monitor command) but
would also be needed if we were to support device assignment
via virtio.

Signed-off-by: default avatarMark McLoughlin <markmc@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (added future masking)
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 357fe2c6

drivers/net/virtio_net.c

+42 −1
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ struct virtnet_info 
	struct virtqueue *rvq, *svq;

	struct net_device *dev;

	struct napi_struct napi;

	unsigned int status;



	/* The skb we couldn't send because buffers were full. */

	struct sk_buff *last_xmit_skb;
@@ -611,6 +612,7 @@ static struct ethtool_ops virtnet_ethtool_ops = { 
	.set_tx_csum = virtnet_set_tx_csum,

	.set_sg = ethtool_op_set_sg,

	.set_tso = ethtool_op_set_tso,

	.get_link = ethtool_op_get_link,

};



#define MIN_MTU 68
@@ -636,6 +638,41 @@ static const struct net_device_ops virtnet_netdev = { 
#endif

};



static void virtnet_update_status(struct virtnet_info *vi)

{

	u16 v;



	if (!virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS))

		return;



	vi->vdev->config->get(vi->vdev,

			      offsetof(struct virtio_net_config, status),

			      &v, sizeof(v));



	/* Ignore unknown (future) status bits */

	v &= VIRTIO_NET_S_LINK_UP;



	if (vi->status == v)

		return;



	vi->status = v;



	if (vi->status & VIRTIO_NET_S_LINK_UP) {

		netif_carrier_on(vi->dev);

		netif_wake_queue(vi->dev);

	} else {

		netif_carrier_off(vi->dev);

		netif_stop_queue(vi->dev);

	}

}



static void virtnet_config_changed(struct virtio_device *vdev)

{

	struct virtnet_info *vi = vdev->priv;



	virtnet_update_status(vi);

}



static int virtnet_probe(struct virtio_device *vdev)

{

	int err;
@@ -738,6 +775,9 @@ static int virtnet_probe(struct virtio_device *vdev) 
		goto unregister;

	}



	vi->status = VIRTIO_NET_S_LINK_UP;

	virtnet_update_status(vi);



	pr_debug("virtnet: registered device %s\n", dev->name);

	return 0;
@@ -793,7 +833,7 @@ static unsigned int features[] = { 
	VIRTIO_NET_F_HOST_TSO4, VIRTIO_NET_F_HOST_UFO, VIRTIO_NET_F_HOST_TSO6,

	VIRTIO_NET_F_HOST_ECN, VIRTIO_NET_F_GUEST_TSO4, VIRTIO_NET_F_GUEST_TSO6,

	VIRTIO_NET_F_GUEST_ECN, /* We don't yet handle UFO input. */

	VIRTIO_NET_F_MRG_RXBUF,

	VIRTIO_NET_F_MRG_RXBUF, VIRTIO_NET_F_STATUS,

	VIRTIO_F_NOTIFY_ON_EMPTY,

};
@@ -805,6 +845,7 @@ static struct virtio_driver virtio_net = { 
	.id_table =	id_table,

	.probe =	virtnet_probe,

	.remove =	__devexit_p(virtnet_remove),

	.config_changed = virtnet_config_changed,

};



static int __init init(void)

include/linux/virtio_net.h

+5 −0
Original line number Diff line number Diff line
@@ -21,11 +21,16 @@ 
#define VIRTIO_NET_F_HOST_ECN	13	/* Host can handle TSO[6] w/ ECN in. */

#define VIRTIO_NET_F_HOST_UFO	14	/* Host can handle UFO in. */

#define VIRTIO_NET_F_MRG_RXBUF	15	/* Host can merge receive buffers. */

#define VIRTIO_NET_F_STATUS	16	/* virtio_net_config.status available */



#define VIRTIO_NET_S_LINK_UP	1	/* Link is up */



struct virtio_net_config

{

	/* The config defining mac address (if VIRTIO_NET_F_MAC) */

	__u8 mac[6];

	/* See VIRTIO_NET_F_STATUS and VIRTIO_NET_S_* above */

	__u16 status;

} __attribute__((packed));



/* This is the first element of the scatter-gather list.  If you don't

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