This series tries to let guest instead of qemu to send the gratuitous packets after migration when guest is capable of doing this. This is needed since it's impossible for qemu to keep track of all configurations (e.g 802.1Q) and mac addresses (more than one mac address may be used by guest). So qemu can't build gratuitous packets for all those configurations properly. The only solution is let guest driver who knew all needed information to do this.
The series first introduces a new runstate which just tracks the state when the migration is finished and guest is about to start. And then we can just trying to notify the guest to send the GARP after changing from this state to running. A model specific announcing method were also also introduced to let each kinds of nic do its own notification. When there's no such method register for the nic, the old style of sending RARP were kept. And the last two patches implemented the virtio-net method of notification. Changes from V6: - introduce a new runstate instead of using a global variable check the state Changes from V5: - use a global variable to decide whether an announcement is needed after migration - align with virtio spec and let guest ack the announcement notification through control vq instead of config status writing Changes from V4: - keep the old behavior that send the gratuitous packets only after migration - decide whether to send gratuitous packets by previous runstate instead of a dedicated parameter - check virtio_net_started() instead of VIRTIO_NET_S_LINK_UP before issue the config update interrupt - move VIRTIO_NET_S_ANNOUNCE to 0x100 and supress guest config write to RO bits - cleanups suggested by Michael Tested with migration within 802.1Q. Jason Wang (5): runstate: introduce prelaunch-migrate state net: announce self after vm is started net: model specific announcing support virtio-net: notify guest to annouce itself virtio-net: compat guest announce hw/pc.h | 6 +++++- hw/virtio-net.c | 30 ++++++++++++++++++++++++++++++ hw/virtio-net.h | 15 ++++++++++++++- include/net/net.h | 2 ++ migration.c | 4 +--- qapi-schema.json | 5 ++++- savevm.c | 8 ++++++-- vl.c | 8 +++++++- 8 files changed, 69 insertions(+), 9 deletions(-)
