qemu hook: event for source host too

[Guy Godfroy]

Hello, this is my first time posting on this mailing list.

I wanted to suggest a addition to the qemu hook. I will explain it 
through my own use case.

I use a shared LVM storage as a volume pool between my nodes. I use 
lvmlockd in sanlock mode to protect both LVM metadata corruption and 
concurrent volume mounting.

When I run a VM on a node, I activate the desired LV with exclusive lock 
(lvchange -aey). When I stop the VM, I deactivate the LV, effectively 
releasing the exclusive lock (lvchange -an).

When I migrate a VM (both live and offline), the LV has to be activated 
on both source and target nodes, so I have to use a shared lock 
(lvchange -asy). That's why I need a hook event on the source host too 
(as far as I know after my tests, the migration event is only triggered 
on the target host).

Is such a feature a possibility?

Thanks for your attention.

Guy Godfroy