Enable remote VNC for kvm+qemu

Do not do it in /etc/libvirt/qemu.conf, but rather do it in the definition file for the guest itself, for example in /etc/libvirt/qemu/serv64_dev.xml. here is an example of the relevant section:

<graphics type='vnc' port='-1' autoport='yes' listen='0.0.0.0'>
  <listen type='address' address='0.0.0.0'/>
</graphics>
<video>
  <model type='vmvga' vram='9216' heads='1'/>
  <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
</video>

Use virsh edit domain name to edit, example virsh edit serv64_dev (from any directory), as it does some additional checks upon exit.

The default editor used by virsh edit is as defined by the $EDITOR environment variable, or VI if it does not exist. add export EDITOR="/bin/nano" to your ~/.bashrc file to set, for example, nano as your default editor.