* Jens Freimann (jfreim...@redhat.com) wrote: > On Tue, May 21, 2019 at 10:33:36AM +0100, Dr. David Alan Gilbert wrote: > > * Jens Freimann (jfreim...@redhat.com) wrote: > > > In "b06424de62 migration: Disable hotplug/unplug during migration" we > > > added a check to disable unplug for all devices until we have figured > > > out what works. For failover primary devices qdev_unplug() is called > > > from the migration handler, i.e. during migration. > > > > > > This patch adds a flag to DeviceState which is set to false for all > > > devices and makes an exception for vfio-pci devices that are also > > > primary devices in a failover pair. > > > > > > Signed-off-by: Jens Freimann <jfreim...@redhat.com> > > > > So I think this is safe in your case, because you trigger the unplug > > right at the start of migration during setup and plug after failure; > > however it's not generally safe - I can't unplug a device while the > > migration is actually in progress. > > I tried to limit it to only allow it in failover case. You're saying > it's missing something and not strict enough? I could allow it only > during migration setup. I guess we'll need a similar exception for > failover in libvirt.
I might be wrong, but I think with your patch I could hot unplug your device part way through migration; where as I think you only care about it doing it at a very specific point during setup. (I still would prefer the hotplug to be done outside qemu, but still that's separate). Dave > regards, > Jens -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
