[Qemu-devel] QEMU Live Migration: arp-like packet patch

[Uri Lublin]

Hello,

We, kvm developers at Qumranet, have been developing a Live Migration solution
    for qemu (and kvm) too (http://kvm.sourceforge.net/migration.html).
We are working with qemu-0.8.2 and are planning to upgrade to the current
    qemu CVS.
Anthony Liguori sent patches implementing Live Migration
    (http://lists.gnu.org/archive/html/qemu-devel/2007-01/msg00245.html).
Some differences are:
  - Anthony's solution uses ssh our solution uses TCP sockets.
  - Anthony's interface is a single qemu-monitor command accepting a uri,
        our interface is a single qemu command accepting a few subcommands.
  - Anthony's solution supports migration start without any preparations,
        our solution requires starting a guest (qemu) on the destination host, and
        establish connection before starting the migration.

Naturally, Anthony's solution can be easily enhanced to support most of our interface.

Since there is no need for two different migration solutions, we'd like to
    cooperate with Anthony (and with you) and contribute some patches which
    are additions to his solution.
Those patches would be based on Anthony's solution (and have to be applied after
    his patches are applied).

The first patch (attached) is an arp-like packet sent (broadcast) when a
    migration successfully completes.
The purpose of this packet is to inform network switches that the guest moved.
Although the most known unsolicited packet is the famous "gratuitous arp", 
    we are not sending an arp packet since we do not know the guest's ip address,
    and we do not want to receive replies.
Instead we use an ethernet "experimental" packet.
The packet is sent only through tap interfaces.
Our implementation currently supports only linux hosts (adding support for
    other operating systems is probably/hopefully as easy as changing the include
    preprocessor directive).

Regards,
    Uri Lublin.

migration_introduce_self_packet.diff
Description: migration_introduce_self_packet.diff