How do I know if I am using libvirt?
You are using libvirt if you manage virtual machines using virsh, virt-manager, or virt-install (pretty much any virtualization tool that starts with virt-*). If you are using hypervisor specific tools like ‘xm’, ‘qemu-kvm’, etc. directly, you probably are not using libvirt. If you have virtual machines on your existing machine and you are using libvirt, ‘virsh list –all’ (usually run as root) should show something.