On 20/05/2017 02:46, Yang Hongyang wrote: >>> How about do O(1) for stopping stage of live migration? >>> Because the cpu is stopped in this phase, it wouldn't cause >>> side effects IMHO, right? >> O(1) update is probably not quite possible, but it's possible to do one >> O(n) update. We tried doing that, but something in virtio broke. > How were you do that? did you put extra begin/commit before/after destination > guest load, so that the destination guest only do one update(of n devs) > throughout > the whole migration? >
Right. However, this is a problem if post_load hooks do DMA. You need to move that DMA to a VM RunState change notifier. Paolo
