On 29/03/2017 17:29, Dr. David Alan Gilbert wrote: >>> 'abort' is not very good too I think. migration is completed, nothing to >>> abort.. (may be successful migration to file for suspend, some kind of >>> vm cloning, etc) >> There is already migrate_cancel. Does it make sense to make it >> reactivate fds if migration is completed? > It's potentially racy to do that. > Imagine if your migration is almost finished and you issue a migrate_cancel, > what happens? > Maybe it cancelled it. > Maybe it just completed in time - and you really better not be accessing > the disks on the source unless you're sure the destination isn't running.
If you want to avoid races, you probably have to use -S anyway on the destination and do more handshaking between source and destination. But yes, just to be safe it'd be better to add a new flag (-f for HMP, 'cancel-completed-migration':true for QMP or something like that). Paolo
