Patent · US Expired

Method for monitoring and emulating privileged instructions of programs in a virtual machine

US7210144B2 · kind B2 · utility

22Cited by
1References
20Claims
0Family size

Assignee

Inventor

Key dates

Filing dateAug 2, 2002
Grant dateApr 24, 2007
Priority date
Expiry dateMar 30, 2024

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F2201/88
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A method for monitoring and emulating privileged instructions of a program that is being executed at a privilege level in a virtual machine is disclosed. A privilege level associated with a received instruction is determined. The instruction privilege level is compared to the program execution privilege level. If the instruction privilege level is valid with respect to the program execution privilege level, the instruction is executed. If the instruction privilege level is invalid with respect to the program execution privilege level: the instruction result is emulated; the number of times the instruction has been received from the program is checked; and if the instruction has been received more than a specified number of times, the instruction is overwritten with one or more instructions with a valid privilege level with respect to the program execution privilege level.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.