Per terminare una macchina virtuale utilizzate virsh:

virsh destroy [domain-name | domain-id | domain-uuid]

This command does an immediate ungraceful shutdown and stops any guest domain sessions (which could potentially lead to file corruptted filesystems still in use by the virtual machine). You should use the destroy option only when the virtual machine's operating system is non-responsive. For a paravirtualized virtual machine, you should use the shutdown option.