Context based virtualization

A computer program product comprising:

• at least one computer-readable medium having instructions encoded therein, the instructions when executed by at least one processor cause said at least one processor to
• operate for context based virtualization by steps comprising the acts of:
• setting up a page table entry to set a permission associated with a MMIO (memory mapped input-output) address, for an instruction to execute untrapped from within an unprivileged domain, the instruction being operative to make a MMIO access at the MMIO address;
• executing the instruction an initial time;
• revoking the permission in response to a first change of context;
• and
• trapping a subsequent execution of the instruction.

A method comprising:

• an act of modulating a signal onto an electromagnetic carrier wave impressed into a tangible medium, or of demodulating the signal from the electromagnetic carrier wave, the signal having instructions encoded therein, the instructions when executed by at least one processor causing said at least one processor to
• operate for context based virtualization by steps comprising the acts of:
• setting up a page table entry to set a permission associated with a MMIO (memory mapped input-output) address, for an instruction to execute untrapped from within an unprivileged domain, the instruction being operative to make a MMIO access at the MMIO address;
• executing the instruction an initial time;
• revoking the permission in response to a first change of context;
• and
• trapping a subsequent execution of the instruction.

An electronic device comprising:

• at least one controller;
• and
• at least one non-volatile memory having instructions encoded therein, the instructions when executed by the controller cause said controller to
• operate for context based virtualization by steps comprising the acts of:
• setting up a page table entry to set a permission associated with a MMIO (memory mapped input-output) address, for an instruction to execute untrapped from within an unprivileged domain, the instruction being operative to make a MMIO access at the MMIO address;
• executing the instruction an initial time;
• revoking the permission in response to a first change of context;
• and
• trapping a subsequent execution of the instruction.