I see that there is a version of the Xen hypervisor for ARM CPUs.
However, most ARM CPUs appear not to have virtualisation extensions (and are not otherwise efficiently virtualisable). Hence I looked into Xen with paravirtualisation for ARM.
But that project seems to be on hold since 2012.
Is there any way to run Xen (presumably the paravirtualisation version) on a Cortex A9?