[ovirt-users] Shutdown all VM's command line

Is there an easy way to do this? I have a UPS connected to my freenas box, and using NUT and UPSC I can monitor the battery level on my centos 7 host. In the case of an emergency, and my UPS goes below, lets say 40% battery, I would like to make a script to shutdown all running VMs, and then reboot the host. Otherwise I am afraid of sending a straight reboot command to the host without taking care of the virtual machines first. Thanks!