ADDING ASPECTS TO VIRTUAL MACHINE MONITORS

• US 20100306766A1
• Filed: 05/28/2009
• Published: 12/02/2010
• Est. Priority Date: 05/28/2009
• Status: Active Grant

• Current Assignee: Red Hat, Inc. (International Business Machines Corporation)
• Original Assignee: Red Hat, Inc. (International Business Machines Corporation)
• Inventors: Schneider, James Paul
• Granted Patent: US 8,429,648 B2
• Time in Patent Office: Days
• US Class Current: 718/1
• CPC Class Codes: G06F 2209/542 Intercept
• CPC Class Codes: G06F 9/45533 Hypervisors; Virtual machine monitors
• CPC Class Codes: G06F 9/545 where tasks reside in different layers, e.g. user- and kernel-space

Abstract

A software generated trap is received by a virtual machine monitor running on a computer system, wherein the software generated trap was caused by a process or a guest operating system of a virtual machine hosted by the computer system. The virtual machine monitor performs a service in response to receiving the software generated trap.

Claims

1. A computer implemented method, comprising:

receiving a software generated trap by a virtual machine monitor running on a computer system, wherein the software generated trap was caused by a process or a guest operating system of a virtual machine hosted by the computer system; and

performing a service by the virtual machine monitor in response to receiving the software generated trap.

2. The method of claim 1, wherein performing the service includes invoking an aspect, the aspect comprising a separate unit of execution from the virtual machine monitor.

3. The method of claim 1, wherein the software generated trap was caused by a system call issued by the process.

4. The method of claim 3, wherein the performed service is associated with the system call, and wherein performing the service generates a result, the method further comprising:

returning the result to at least one of the process or the guest operating system.

5. The method of claim 4, further comprising:

determining whether the system call is managed by the virtual machine monitor; and

if the system call is fully managed by the virtual machine monitor, performing the service associated with the system call to generate the result and returning the result to the process.

6. The method of claim 4, further comprising:

determining whether the system call is partially managed by the virtual machine monitor; and

if the system call is partially managed by the virtual machine monitor, performing the service to generate a partial result and passing the partial result and the system call to the guest operating system.

7. The method of claim 3, further comprising:

passing the system call to the guest operating system, the guest operating system to perform a service requested by the system call and to pass a result to the process;

modifying the process or a process environment of the process so that when the process receives the result, the process passes at least one of the system call and the result back to the virtual machine monitor; and

performing an other service in response to receiving the system call or the result.

8. The method of claim 7, wherein performing the other service includes modifying the received result, the method further comprising:

passing the modified result to the process.

9. The method of claim 1, wherein the software generated trap is caused by an attempt by the process or the guest operating system to execute a privileged or illegal instruction.

10. The method of claim 1, further comprising:

modifying the process or a process environment of the process so that a next action of the process will cause another software generated trap.

11. A computer readable storage medium including instructions that, when executed by a processing system, cause the processing system to perform a method, comprising:

receiving a software generated trap by a virtual machine monitor running on a computer system, wherein the software generated trap was caused by a process or a guest operating system of a virtual machine hosted by the computer system; and

performing a service by the virtual machine monitor in response to receiving the software generated trap.

12. The computer readable storage medium of claim 11, wherein performing the service includes invoking an aspect, the aspect comprising a separate unit of execution from the virtual machine monitor.

13. The computer readable storage medium of claim 11, wherein the software generated trap was caused by a system call issued by the process.

14. The computer readable storage medium of claim 13, wherein the performed service is associated with the system call, and wherein performing the service generates a result, the method further comprising:

returning the result to at least one of the process or the guest operating system.

15. The computer readable storage medium of claim 14, the method further comprising:

determining whether the system call is managed by the virtual machine monitor; and

if the system call is fully managed by the virtual machine monitor, performing the service associated with the system call to generate the result and returning the result to the process.

16. The computer readable storage medium of claim 14, the method further comprising:

determining whether the system call is partially managed by the virtual machine monitor; and

if the system call is partially managed by the virtual machine monitor, performing the service to generate a partial result and passing the partial result and the system call to the guest operating system.

17. The computer readable storage medium of claim 13, the method further comprising:

passing the system call to the guest operating system, the guest operating system to perform a service requested by the system call and to pass a result to the process;

modifying the process or a process environment of the process so that when the process receives the result, the process passes at least one of the system call and the result back to the virtual machine monitor; and

performing an other service in response to receiving the system call or the result.

18. The computer readable storage medium of claim 17, wherein performing the other service includes modifying the received result, the method further comprising:

passing the modified result to the process.

19. The method of claim 11, wherein the software generated trap is caused by an attempt by the process or the guest operating system to execute a privileged or illegal instruction.

20. The computer readable storage medium of claim 11, the method further comprising:

modifying the process or a process environment of the process so that a next action of the process will cause another software generated trap.

21. A computing apparatus, comprising:

a memory including instructions for a virtual machine monitor;

a processor, connected with the memory, to execute the instructions; and

the virtual machine monitor to virtualize the memory and the processor, the virtual machine monitor further to;

receive a software generated trap, wherein the software generated trap was caused by a process or a guest operating system of a virtual machine hosted by the computing apparatus; and

perform a service in response to receiving the software generated trap.

22. The computing apparatus of claim 21, wherein performing the service includes invoking an aspect, the aspect comprising a separate unit of execution from the virtual machine monitor.

23. The computing apparatus of claim 21, wherein the software generated trap was caused by a system call issued by the process.

24. The computing apparatus of claim 23, wherein the performed service is associated with the system call, and wherein performing the service generates a result, the virtual machine monitor further to:

return the result to at least one of the process or the guest operating system.

25. The computing apparatus of claim 24, the virtual machine monitor further to:

determine whether the system call is managed by the virtual machine monitor; and

if the system call is fully managed by the virtual machine monitor, perform the service associated with the system call to generate the result and return the result to the process.

26. The computing apparatus of claim 24, the virtual machine monitor further to:

determine whether the system call is partially managed by the virtual machine monitor; and

if the system call is partially managed by the virtual machine monitor, perform the service to generate a partial result and pass the partial result and the system call to the guest operating system.

27. The computing apparatus of claim 23, the virtual machine monitor further to:

pass the system call to the guest operating system, the guest operating system to perform a service requested by the system call and to pass a result to the process;

modify the process or a process environment of the process so that when the process receives the result, the process passes at least one of the system call and the result back to the virtual machine monitor; and

perform an other service in response to receiving the system call or the result.

28. The computing apparatus of claim 27, wherein performing the other service includes modifying the received result, the virtual machine monitor further to:

pass the modified result to the process.

29. The computing apparatus of claim 21, wherein the software generated trap is caused by an attempt by the process or the guest operating system to execute a privileged or illegal instruction.

30. The computing apparatus of claim 21, the virtual machine monitor further to:

modify the process or a process environment of the process so that a next action of the process will cause another software generated trap.