[libvirt] Permissions and ownership on /dev/kvm keep reverting after starting a vm

Hey guys, /dev/kvm permissions and ownership keeps reverting after starting a vm. The ownership and permissions keep going back to crw-rw—— root root .... After starting a vm. I have to revert the perms and ownership to: crw-crw-crw root kvm .... To start any vm but it goes back to the first set of permissions as soon as I start another vm. Any hints what I could check? Cheers, Tom Sent from my iPhone