[Qemu-devel] [V6 PATCH 0/4] Send gratuitous packets by guest

[Jason Wang]

This an update of series that let guest and qemu to be co-operated to
send gratuitous packets when needed (e.g after migration).

As it's hard for qemu to track the network configuration in guest such
as bondings, vlans or ipv6s. Current gratuitous (RARP packets for
primary mac address) may not work under those situations. The better
method is to allow guest to send them when they can.

The series first introduce a model specific function in order to let
nic models to use a device specific way to announce the link
presence. With this, virtio-net backend were modified to notify the
guest (through config update interrupt) and let guest send the
gratuitous packet when needed.

The first user would be virtio-net.

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

---

Jason Wang (4):
      net: announce self after vm start
      net: model specific announcing support
      virtio-net: notify guest to annouce itself
      virtio-net: compat guest announce support


 hw/pc_piix.c    |   35 +++++++++++++++++++++++++++++++++++
 hw/virtio-net.c |   29 +++++++++++++++++++++++++++++
 hw/virtio-net.h |   14 ++++++++++++++
 migration.c     |    2 +-
 migration.h     |    2 ++
 net.h           |    2 ++
 savevm.c        |    8 +++++---
 vl.c            |    5 +++++
 8 files changed, 93 insertions(+), 4 deletions(-)

-- 
Jason Wang