Mine

kernel = "/usr/lib/xen/boot/hvmloader"
builder='hvm'
memory = 256
shadow_memory = 64
name = "Boss"
vif = [ 'mac=00:16:3e:18:98:af' ];
disk = [ 'file:/mnt/Xen_Systems/Live/Boss.img,ioemu:hda,w', 'phy:/dev/disk/by-uuid/2a7ae14f-1b51-4d0e-88a\
6-f72d72487f8d,ioemu:hdb,w']
device_model = '/usr/lib/xen/bin/qemu-dm'
boot="c"
sdl=0
vnc=1