apt install xen-hypervisor
systemctl reboot

type       = "hvm"
name       = "obsd"
memory     = 4096
vcpus      = 2
disk       = [ '/opt/xen/install78.iso,,xvdc,cdrom', '/dev/vg0/lv-obsd,,xvda' ]
vif        = [ 'mac=00:16:3e:a1:ff:01,bridge=xenbr0' ]
serial     = "pty"
vnc        = 1
vnclisten  = 127.0.0.1
vncdisplay = 42

cat > /etc/network/interfaces.d/xenbr0 << EOF
auto xenbr0
iface xenbr0 inet static
  address 192.168.100.1
  netmask 255.255.255.0
  bridge_ports none
EOF

xl create -c /etc/xen/auto/obsd.cfg