On Mon, Sep 27, 2010 at 08:50:44PM +0800, Jason Wang wrote: > This series of patch tries to solve the problem of migration with nics who have > multiple mac addresses or vlans. Qemu currently only send gratuitous packet for > first mac address, so after migration other mac addresses or vlans were broken. > > The information of mac addresses and vlans were often stored in model specific > structure, so a model specific function were introduced and used after > migration during self announcement. A sample announcing function for virtio-net > is also implemented in this series. Other model could be also done in this > way. The previous method is kept for the model who does not implement model > specific function. > > While there's still issues which need your comments and need to be solved. > > 1 Virtio specification allows filtering any number of destination mac addresses > which looks impossible for the migration. Then we need to record an unlimited > numbers of mac address which is not safe. > > 2 Virtio specification allows filtering of vlan and mac address but neither the > spec nor the implementation could decide the mappings between vlans and mac > addresses. This could make it impossible to send correct tagged gratuitous > packet. > For issue 1, the number of mac addresses were limited in this series. > For issue 2, I suspect it needs the modification of guest drivers to send the > mappings in order to make migration work. Or is there any method to get this > without touching guest drivers? For safety, all the mac addresses were only > announced when there's no vlan in guest which means the vlan after migration is > still broken. > > This patchset is just an RFC and need your suggestions and comments. > > Thanks. For 1, all guests actually do is on error status is print a warning. This does not sound all that useful, does it? I note that we also have a similar issue with promisc mode. For 2, we could at least make it work for a common case of 1 mac, which would already cover many users. > --- > > Jason Wang (4): > net: move announce_self_create to net.c > net: Introduce model specific nic announce function > virtio-net: Limit the num of uni/multicast mac addresses > virtio-net: implement virtio-net specific announce function > > > hw/virtio-net.c | 47 ++++++++++++++++++++++++++++++++++++++++++----- > net.c | 31 +++++++++++++++++++++++++++++++ > net.h | 3 +++ > savevm.c | 42 ++++++++---------------------------------- > 4 files changed, 84 insertions(+), 39 deletions(-) > > -- > Jason Wang -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
