This patch extends libvirt's XML to include a paramater Xen already supports in sexpr, "bootloader_args." The bootloader_args parameter lets you pass arguments -- "mac=aa:12:34:56:78:90" for example -- to a bootloader program that xend invokes when it starts a guest. One such program, pypxeboot, uses the mac= argument to communicate with a dhcp server and retrieve the pxeboot kernel and initrd for a paravirt guest. The patch includes new tests for the bootloader_args XML and sexpr, which pass. Note that for the head of current libvirt, the virsh tests do not pass and virsh will not connect to the xen hypervisor. I don't know if this is my own build environment or some other issue. However the failure is the same with or without this patch, so I am submitting it anyway. Please let me know what you think... --Hugh -- Red Hat Virtualization Group http://redhat.com/virtualization Hugh Brock | virt-manager http://virt-manager.org hbrock@redhat.com | virtualization library http://libvirt.org