libvirt users - Jan 2015 - [libvirt]configuration question about usinf for [xen4.5][libxl]

What configuration should be set in a custom compiled libvirt to get the most
out of the xen libxl?
  [ -f Makefile ] || ./configure --prefix=/usr
--libexec=/usr/lib/"$pkgname" --sbindir=/usr/bin \
--with-storage-lvm=yes --with-udev=yes --without-hal --disable-static \
--with-init-script=systemd --with-systemctl=yes --with-systemd-daemon=yes \
--with-qemu-user=nobody --with-qemu-group=nobody \	--without-netcf
--with-interface --with-lxc --with-storage-iscsi \    --with-xen=yes
--with-libxl=yes 	# --with-audit
After compiling what needs done to configure libvirt to work with xen libxl
because all I seem to be getting is:
error: failed to connect to the hypervisorerror: no connection driver available
for //libxl[dragon@archxen ~]$