KVM: boot VM from PXE or ISO image

Boot from PXE

Scenario: you have a KVM virtualization host with some VMs and you want to boot one of them from PXE instead of the virtual hard drive.

Magic incantation:

1. edit the /kvm/vm/[guestname].xml file
2. find the line that says <boot dev='hd'/>
3. add a line before it that says <boot dev='network'/>

Boot from ISO

Second scenario: you have a KVM virtualization host with some VMs and you want to boot one of them from an ISO that you have downloaded.

Magic incantations available here:
* http://mycfg.net/articles/booting-from-a-cdrom-in-a-kvm-guest-with-libvirt.html