Some vhost user backends are able to support live migration.
To provide this service the following features must be added:
1. Add the VIRTIO_NET_F_GUEST_ANNOUNCE capability to vhost-net when netdev
backend is vhost-user.
2. Provide a nop receive callback to vhost-user.
This callback is called by:
* qemu_announce_self after a migration to send fake RARP to avoid network
outage for peers talking to the migrated guest.
- For guest with GUEST_ANNOUNCE capabilities, guest already sends GARP
when the bit VIRTIO_NET_S_ANNOUNCE is set.
=> These packets must be discarded.
- For guest without GUEST_ANNOUNCE capabilities, migration termination
is notified when the guest sends packets.
=> These packets can be discarded.
* virtio_net_tx_bh with a dummy boot to send fake bootp/dhcp request.
BIOS guest manages virtio driver to send 4 bootp/dhcp request in case of
dummy boot.
=> These packets must be discarded.
Signed-off-by: Thibaut Collet <thibaut.collet@6wind.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Thibaut Collet <thibaut.collet@6wind.com>
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