1. A method of managing processing with a computing environment, said method comprising: initiating, by a host processor processing in a first architectural mode, a first guest virtual machine, the first guest virtual machine to process in the first architectural mode, the first architectural mode having a first instruction set architecture and providing a first set of architectural functions; initiating, by the host processor, a second guest virtual machine, the second guest virtual machine to process in a second architectural mode, wherein the second architectural mode has a second instruction set architecture and provides a second set of architectural functions, the second set of architectural functions being a reduced set of architectural functions provided in the first set of architectural functions, wherein a selected architectural function provided in the first set of architectural functions is absent from the second set of architectural functions, the second architectural mode being a function inhibit mode; and performing processing by the second guest virtual machine in the second architectural mode, wherein the performing processing overrides one or more controls associated with the selected architectural function that are defined to control execution of the second guest virtual machine.