[libvirt] [PATCH 3/3] qemu: add/remove bridge fdb entries as guest CPUs are started/stopped

[Michal Privoznik]

On 12.12.2014 17:34, Laine Stump wrote:
> When libvirt is managing a bridge's forwarding database (FDB)
> (macTableManager='libvirt'), if we add FDB entries for a new guest
> interface even before the qemu process is created, then in the case of
> a migration any other guest attached to the "destination" bridge will
> have its traffic immediately sent to the destination of the migration
> even while the source domain is still running (and the destination, of
> course, isn't). To make sure that traffic from other guests on the new
> host continues flowing to the old guest until the new one is ready, we
> have to wait until the new guest CPUs are started to add the FDB
> entries.
>
> Conversely, we need to remove the FDB entries from the bridge any time
> the guest CPUs are stopped; among other things, this will assure
> proper operation during a post-copy migration (which is just the
> opposite of the problem described in the previous paragraph).
> ---
>   src/qemu/qemu_command.c   | 10 +++-------
>   src/qemu/qemu_interface.c | 26 ++++++++++++++++++++++++++
>   2 files changed, 29 insertions(+), 7 deletions(-)

ACK

Michal