Comment 3 for bug 611144

The intent is to not regress existing images.
The protection against doing so is:
if (kernel file looks like a linux kernel) or (virtio root); then
  use old path
else
  load the aki payload via multiboot from a floppy
fi

I would like to change that to be:
if (kernel file is a multiboot compliant image) and (!virtio root); then
  load the aki payload via multiboot from a floppy
else
  use old path
fi

The problem right now is that I do not have a good check for "is a multiboot compliant image".
Updates can be made to the "is_multiboot_img" subroutine of gen_kvm_libvirt_xml