I installed trisquel 9 and tried to get one of my qemu images working, but
couldn't get kvm to start. I added my user to the libvirt group not
understanding why else my user would not be able to start it. Two kvm modules
are loaded (kvm and kvm_intel) and kvm is attached to the irqbypass module.
I believe the installation of these programs caused libvirt users to be
created. In the login box one of those users was available, but I deleted
them fearing they were a security issue.
Trying to install qemu-kvm again does not bring them back.