Xen offers a couple of ways to load and start a kernel and you'd want to start a kernel in long or protected mode. Ideally, you also use the hypervisors virtual

Xen offers a couple of ways to load and start a kernel and you'd want to start a kernel in long or protected mode. Ideally, you also use the hypervisors virtual device interfaces instead of scanning for emulated devices. I don't know if the sane startup protocol is final but here are some pieces of documentation: http://xenbits.xen.org/docs/4.7-testing/misc/hvmlite.html http://xenbits.xen.org/docs/4.7-testing/misc/hvmlite.html http://xenbits.xen.org/docs/4.7-testing/misc/pvh.html http://xenbits.xen.org/docs/4.7-testing/misc/pvh.html The nice thing about ring-0 is that on modern hardware with SR-IOV, a VM can be associated with devices and the multiplexing that had to be done within a kernel or hypervisor can now be done in hardware.