libvirt users - Jun 2020 - RBD volume pools and locks

Hello,

One of my libvirt cluster is using a RBD volume pool. I wish that I 
could configure libvirt lock manager to use RBD locks. Is that possible?

I read here https://libvirt.org/kbase/locking.html that libvirt lock 
manager is shipped with 2 active plugins. Is there any other plugins 
that exist?

Thanks.

Guy Godfroy