On 10/27/2011 09:32 AM, Rusty Russell wrote: > On Wed, 26 Oct 2011 16:49:12 +0800, Jason Wang <jasow...@redhat.com> wrote: >> Network connections in guest need to be kept after migration. This is done by >> sending gratuitous packet and let switch learn new port of the mac >> address. As hypervisor does not have the knowledge of guest network >> configurations such as tagged vlan or ipv6, it may require guest to send >> gratuitous packet. >> >> This patch introduces a new feature bit of virtio network adapter - >> VIRTIO_NET_F_GUEST_ANNOUNCE which is used to indicate the ability to send >> gratuitous packets by guest. A new status bit - VIRTIO_NET_S_ANNOUNCE is also >> introduced to notify the guest the need for sending gratuitous packet. When >> guest notice this, it should clear it and send the gratuitous packet. >> >> Signed-off-by: Jason Wang <jasow...@redhat.com> > > Thanks! I applied it manually, since you didn't enable change tracking > in LyX (I like to produce a PDF showing changes between versions). >
Ok, I would enable it next time. > Some minor cleanups, here's the main text below. > > Cheers, > Rusty. > > Gratuitous Packet Sending > > If the driver negotiates the VIRTIO_NET_F_GUEST_ANNOUNCE, it can ask the > guest to send gratuitous packets; this is usually done after the guest has > been physically migrated, and needs to announce its presence on the new > network links. (As hypervisor does not have the knowledge of guest network > configuration (eg. tagged vlan) it is simplest to prod the guest in this way). > > The Guest needs to check VIRTIO_NET_S_ANNOUNCE bit in status field when it > notices the changes of device configuration. > > Processing this notification involves: > > Clearing VIRTIO_NET_S_ANNOUNCE bit in the status field. > > Sending the gratuitous packets. Thanks for the cleanup. > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
