Patent ID: 7421689

Claim:
A computer processor that executes instructions and that supports virtual machine monitor operation and implementation, the computer processor comprising: a virtualization-mode processor state for execution of non-virtual-machine-monitor instructions; a non-virtualization-mode processor state for execution of virtual machine monitor instructions; and a virtualization-mode-switch instruction that before switching from one mode to another, checks to ensure that page attributes of a virtual memory page containing the virtualization-mode-switch instruction are compatible with the virtualization-mode-switch instruction, when executed by a process running in virtualization mode, checks to ensure that a current priority level is a most privileged virtualized priority level before switching from virtualization mode to non-virtualization mode, without incurring an interruption, to enable execution of one ore more virtual machine monitor instructions; and when executed by a process running in non-virtualization mode, checks to ensure that the current priority level is a highest priority level before switching from non-virtualization mode to virtualization mode without incurring an interruption.