KVM, no questions asked. Xen — party stuff working below level linuxoveho kernel and grooving it, and the KVM works directly in the kernel. Why do you need extra padding? From the point of view of efficiency in this case there is no difference.
Eulalia22 answered on July 9th 19 at 13:01
KVM on top of the Zen dies
Esta_Upton answered on July 9th 19 at 13:03
Tried both, prefer KVM. XEN seemed obvious - some things should simply work - they just don't work :( After repeated attempts to have one comp FreeBSD and Windows, ends every time the same mate :( XEN was forever pushed into the far corner.