host identifier

Hello community, I am using OpenStack nova and realize that nova now uses host fqdn from libvirt as a uniq identifier for a compute node. The issue is that host might need to change its fqdn under some rare circumstances and lose some usage data due to the nova manages compute node resources. My question is: does libvirt already export host uuid identifier to other applications? I skim through the code base and find there is host uuid related code which reads /etc/machine-id to obtain a uniq uuid for migration, but seems this uuid cannot be obtained through virsh interface. Thank you for you help. -- Best Regards, Jiatong Shen