Hi, I am using Libvirt with XEN hypervisor to manage the VM. I see there are 3 kinds of Virtual BIOS for XEN Guest VM, they are ROMBIOS,SEABIOS, OVMF ( is disabled by default as XEN Supporters said ). But I don't know how to pass the BIOS options to the Guest from XML file. Could you please suggest how to change the Virtual BIOS for the Guest from XML file in Libvirt or give some clues to do that? Below is the link that I asked XEN support: http://osdir.com/ml/general/2014-04/msg32102.html Thank for your time!