[net-next V7 PATCH] virtio-net: send gratuitous packets when needed

David Miller
Fri, 13 Apr 2012 17:38:04 -0000

From: Jason Wang <jasowang at redhat.com>
Date: Thu, 12 Apr 2012 14:43:52 +0800

> As hypervior does not have the knowledge of guest network configuration,
it's
> better to ask guest to send gratuitous packets when needed.
>
> This patch implements VIRTIO_NET_F_GUEST_ANNOUNCE feature: hypervisor would
> notice the guest when it thinks it's time for guest to announce the
link
> presnece. Guest tests VIRTIO_NET_S_ANNOUNCE bit during config change
interrupt
> and woule send gratuitous packets through netif_notify_peers() and ack the
> notification through ctrl vq.
>
> We need to make sure the atomicy of read and ack in guest otherwise we may
ack
> more times than being notified. This is done through handling the whole
config
> change interrupt in an non-reentrant workqueue.
>
> Signed-off-by: Jason Wang <jasowang at redhat.com>

Michael, Rusty, et al.?