KVM supports nested virtualization, so you can run Xen inside a KVM VM. VMware does as well. Xen paravirt has always run inside VMs, even before nesting suppo

KVM supports nested virtualization, so you can run Xen inside a KVM VM. VMware does as well. Xen paravirt has always run inside VMs, even before nesting support. I used to run it in VMware all the time for development purposes.