Enabling Virtual Machine support

[Darrell Michaud]

Just to round out the thread..

As people have already stated, the intel VT optimizations are not required
to support virtualization, or even hypervisors. Vmware ESX is an example
of a decent hypervisor that does not require these CPU capabilities to be
present. KVM on the other hand requires either VT or AMD-V to run.

Even when they are enabled, it is not always true that they are a
performance win. There was a study published a couple years back that
showed enabling the VT instructions can result in lower performance for
some use cases, specificallly heavy use of non-memory I/O if I remember
clearly.