1. In a hardware computer system, a method: providing a hardware virtualization software layer comprising virtual machine guard software, wherein the virtual machine guard software has a dedicated purpose to prevent the operation of malware software, such malware software characterized by a purpose to circumvent the intended operation of a system; recognizing, by the virtual machine guard software, an attempt to use hardware virtualization; determining a source that initiated the attempt; associating the source with an identifier; and allowing the attempt if the identifier is on a list of predetermined identifiers that are allowed.