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: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (added future masking)
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 30ae6d9..9b33d6e 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -42,6 +42,7 @@
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 @@
.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 @@
#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 @@
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 @@
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 @@
.id_table = id_table,
.probe = virtnet_probe,
.remove = __devexit_p(virtnet_remove),
+ .config_changed = virtnet_config_changed,
};
static int __init init(void)
