1. A non-transitory computer readable medium storing instructions, that when executed by a computer, cause the computer to: execute a first system software instance in a virtualized environment; execute a policy enforcement point (PEP); and receive from a policy decision point (PDP) a decision as to whether a second system software instance should be allowed to execute concurrently with the first system software instance in the virtualize environment, wherein the policy enforcement point (PEP) is configured to selectively prevent the execution of the second system software instance in the virtualized environment based on the decision of the policy decision point (PDP).