Preparing for the realtime future

Why are you considering that we might run RT systems in a VM? All our RT systems under test run on native hardware. Anything else would not make sense. However, there is one RT system that runs a non-RT kvm guest to ensure that the guest does not interfere with the RT capabilities of the host. We do these test, since it was an OSADL funded project (executed long ago by tglx) to fix kvm induced latencies of the host.

BTW: Even if the host kernel is RT, a fully virtualized guest cannot have RT capabilities irrespective of what kernel you use.