Re: [Qemu-devel] [V5 PATCH 0/4] Send gratuitous packets by guest

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Mar 26, 2012 at 05:10:15PM -0500, Anthony Liguori wrote:
> On 03/16/2012 03:54 AM, Jason Wang wrote:
> >This an update of series that let guest and qemu to be co-operated to
> >send gratuitous packets when needed such as after migration, loadvm
> >and continuing.
> >
> >As it's hard for qemu to track the network configuration in guest such
> >as bondings, vlans or ipv6. So current gratuitous may not work under
> >those situations.
> 
> Can you be more specific about the failure scenarios?
> 
> Does this mean that migration cannot work today with guests using
> ipv6?  I don't think just pushing this to the guest is an acceptable
> solution in the short term.
> 
> Are there scenarios we cannot handle no matter what in the host?

Consider a nested virt scenario. It seems clear that you either
must notify the guest about migration, or learn nested
guest macs.

> Does this mean that for emulated drivers, we're completely out of
> luck?
> 
> Regards,
> 
> Anthony Liguori

For these, I think we can cause announcements by sending link up event
to the guest.

-- 
MST