It should be great if we can use an unmodified guest for dom0 or the driver domain. We found a way to achieve that. Since Xen's inception, the first guest on Xen is always a para-virtualized domain, and it can be modified Linux, NetBSD, and Solaris etc. In this way, dom0 can achieve near-native performance, so it is commonly used in the server market. However, modifications to guest kernels also implies limitations. For example, it can't support Windows OS as the dom0 or the driver domain. With the rapid evolution of hardware-assisted virtualization (e.g. VMX, VT-d technologies), HVM domains also can achieve comparable performance with para-virtualization. And, it's high time for Xen to such an unmodified guest as the dom0. In the presentation, we discuss its architectural changes and its benefits compared with the traditional PV or HVM dom0, and we also introduce what we have done.
