* Peter Xu (pet...@redhat.com) wrote: > On Tue, Dec 19, 2017 at 10:58:59AM +0000, Dr. David Alan Gilbert wrote: > > * Peter Xu (pet...@redhat.com) wrote: > > > It was allowed in the past to even cancel a postcopy migration, but it > > > does not really make sense, and no one should be using it, since > > > cancelling a migration during postcopy means crashing the VM at no time. > > > > > > Let's just use re-use this command as a way to pause the postcopy > > > migration when we detected that we are in postcopy migration. This can > > > be used when we want to trigger the postcopy recovery manually. > > > > > > Signed-off-by: Peter Xu <pet...@redhat.com> > > > > Yes, OK, this is a little odd without having any flags or anything, but > > it's essentially the saem reason that cancel exists - to stop a > > migration we know that's broken for some reason. > > > > (I could argue whether this should be special cased in migrate_fd_cancel > > instead, but that's just a preference). > > > > > > Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com> > > Firstly, thanks for the r-b. > > Now after knowing your iptable test, I think we reached a consensus > that we need to provide a command (for example, reuse migrate-cancel) > to allow destination to shutdown its incoming migration port too. At > the same time, if we want to make sure the command can always work on > destination, we'd better also let that command to be OOB-capable. > > However I'm not sure whether I can let migrate-cancel be OOB-capable > since recently we added bdrv_invalidate_cache_all() into > migrate_fd_cancel(). That invalidation needs some mutex which might > block. I don't know whether it means migrate-cancel will no longer be > suitable as an OOB command now. > > So, maybe now I can do this: firstly, drop this patch; then add a new > command to do the shutdown explicitly (allow either src/dst to > shutdown its migration fd) and keep migrate-cancel untouched. In that > case, I can make sure the new command will be OOB-compatible. > > What do you think?
Yes I'm fine with that; misusing another command did feel a bit odd. Dave > -- > Peter Xu -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
