Autonomous selection between multiple virtualization techniques implemented in a virtualization layer of a virtualized computer system. The virtual machine monitor implements multiple virtualization support subsystems that each provide for the comprehensive handling of potential virtualization exceptions. A virtual machine monitor resident performance monitor computes relative virtualization overhead costs that are and would be incurred in using different virtualization support subsystems for virtualization exceptions that occur in executing a guest operating system within a defined interval. Dependent on the relative virtualization overhead costs determined, the virtual machine monitor resident virtualization selection control switches the virtual machine monitor to use the optimal virtualization support subsystem for handling virtualization exceptions that occur over a second defined interval.