all,
qemu with sdl always end up with "-nographic" since r13745 (Merge VFB 
support for PV and HVM guests.)

attached patch can fix it.

Signed-off-by: Zhai Edwin <edwin.zhai@intel.com>

but vnc hvm guest still fail restore with

  File 
"/home/gzhai/srcs/hg/tip/dist/install/usr/lib/python/xen/xend/XendDomainInfo.py", 
line 1261, in _createDevices
  File 
"/home/gzhai/srcs/hg/tip/dist/install/usr/lib/python/xen/xend/XendDomainInfo.py", 
line 1237, in _createDevice
  File 
"/home/gzhai/srcs/hg/tip/dist/install/usr/lib/python/xen/xend/server/vfbif.py", 
line 48, in createDevice
  File 
"/home/gzhai/srcs/hg/tip/dist/install/usr/lib/python/xen/xend/server/DevController.py", 
line 111, in createDevice
VmError: Device 0 (vfb) is already connected.

thanks,
edwin