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/include/linux/virtio_net.h b/include/linux/virtio_net.h
index 5cdd0aa..f76bd4a 100644
--- a/include/linux/virtio_net.h
+++ b/include/linux/virtio_net.h
@@ -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