Method and apparatus for scheduling virtual machine access to shared resources

• US 20060064697A1
• Filed: 09/23/2004
• Published: 03/23/2006
• Est. Priority Date: 09/23/2004
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Anderson, Andrew V., Bennett, Steven M., Cota-Robles, Erik C., Kagi, Alain, Jablonski, Gregory M.
• Granted Patent: US 7,797,699 B2
• Time in Patent Office: Days
• US Class Current: 718/103
• CPC Class Codes: G06F 9/5011 the resources being hardware resources other than CPUs, Servers and Terminals

Abstract

A method for managing IO requests from a virtual machine to access IO resources on a physical machine includes determining a request priority associated with an IO request. The IO request is placed in an appropriate queue in response to determining the request priority.

Claims

1. A method for managing input/output (IO) requests on a system executing a virtual machine to access an IO resource, comprising:

determining a request priority associated with an IO request; and

placing the IO request in one of a plurality of pending request queues in response to determining the request priority.

2. The method of claim 1, further comprising selecting an IO request from one of the plurality of pending request queues for execution.

3. The method of claim 2, further comprising examining in a priority ordering the plurality of pending request queues to select an IO request for execution.

4. The method of claim 1, further comprising reordering IO requests present in the plurality of pending request queues.

5. The method of claim 1, wherein determining the request priority comprises:

determining an identity priority based on at least one of the virtual machine issuing the IO request, the IO resource and an application running in the virtual machine issuing the IO request; and

using the identity priority as the request priority.

6. The method of claim 5, wherein the identity priority is determined using at least one of an admission control protocol when the virtual machine is created, dynamic profiling and static assignment.

7. The method of claim 1, wherein determining the request priority comprises:

determining a status priority based on at least one of a status of the virtual machine issuing the IO request, a status of the virtual machine monitor, a status of the IO resource, a status of a second IO resource, and a status of an application executing in the virtual machine issuing the IO request; and

using the status priority as the request priority.

8. The method of claim 1, wherein determining the request priority comprises identifying a tag associated with the IO request that indicates the request priority associated with the IO request.

9. The method of claim 8, wherein the tag is generated by software on one of the virtual machine and a virtual machine monitor.

10. The method of claim 1, wherein the IO request comprises an attempt to access one of a display device, an input device, an output device, a storage device and a communication device.

11. The method of claim 1, wherein the plurality of pending request queues comprises a preferred queue and a non-preferred queue.

12. The method of claim 11 further comprising checking the preferred queue for IO requests to select for execution.

13. The method of claim 12 further comprising checking the non-preferred queue for IO requests to select for execution after checking the preferred queue.

14. The method of 13, further comprising executing an IO request in the non-preferred queue after IO requests in the preferred queue have been executed.

15. An article of manufacture comprising a machine accessible medium including sequences of instructions, the sequences of instructions including instructions which when executed causes the machine to perform:

determining a request priority associated with an IO request; and

placing the IO request in one of a plurality of pending request queues in response to determining the request priority.

16. The article of manufacture of claim 15, further comprising instructions which when executed causes the machine to perform selecting an IO request from one of the plurality of pending request queues for execution.

17. The article of manufacture of claim 16, further comprising instructions which when executed causes the machine to perform examining in a priority ordering the plurality of pending request queues to select an IO request for execution.

18. The article of manufacture of claim 15, further comprising instructions which when executed causes the machine to perform reordering IO requests present in the plurality of pending request queues.

19. The article of manufacture of claim 15, wherein determining the request priority comprises:

determining an identity priority based on at least one of the virtual machine issuing the IO request, the IO resource and an application running in the virtual machine issuing the IO request; and

using the identity priority as the request priority.

20. The article of manufacture of claim 15, wherein the identity priority is determined using at least one of an admission control protocol when the virtual machine is created, dynamic profiling and static assignment.

21. The article of manufacture of claim 15, wherein determining the request priority comprises:

determining a status priority based on at least one of a status of the virtual machine issuing the IO request, a status of the virtual machine monitor, a status of the IO resource, a status of a second IO resource, and a status of an application executing in the virtual machine issuing the IO request; and

using the status priority as the request priority.

22. The article of manufacture of claim 15, wherein determining the request priority comprises identifying a tag associated with the IO request that indicates the request priority associated with the IO request.

23. The article of manufacture of claim 22, wherein the tag is generated by software on one of the virtual machine and a virtual machine monitor.

24. The article of manufacture of claim 15, wherein the IO request comprises an attempt to access one of a display device, an input device, an output device, a storage device and a communication device.

25. The article of manufacture of claim 15, wherein the plurality of pending request queues comprises a preferred queue and a non-preferred queue.

26. The article of manufacture of claim 25, further comprising instructions which when executed causes the machine to perform checking the preferred queue for IO requests to select for execution.

27. The article of manufacture of claim 26, further comprising instructions which when executed causes the machine to perform checking the non-preferred queue for IO requests to select for execution after checking the preferred queue.

28. The article of manufacture of claim 27, further comprising instructions which when executed causes the machine to perform executing an IO request in the non-preferred queue after IO requests in the preferred queue have been executed.

29. A physical event dispatcher, comprising:

a queue assignor unit to determine a request priority associated with an input/output (IO) request from a virtual machine to access an IO resource.

30. The physical event dispatcher of claim 30, wherein the queue assignor unit comprises a virtual machine status unit to identify a virtual machine making an IO request and to determine a priority given to the IO request based on an identity of the virtual machine.

31. The physical event dispatcher of claim 30, wherein the queue assignor unit comprises a virtual machine interface to receive an indication from guest software that an IO request requires a high priority.

32. The physical event dispatcher of claim 30, wherein the queue assignor unit comprises a tag identifier unit to identify a priority requested for an IO request.

33. The physical event dispatcher of claim 30, further comprising a plurality of pending request queues.

34. A computer system, comprising:

a memory; and

a processor to execute instructions in memory to generate a physical event dispatcher that includes a queue assignor unit to determine a request priority associated with an input/output (IO) request from a virtual machine to access an IO resource.

35. The computer system of claim 34, wherein the queue assignor unit comprises a virtual machine status unit to identify a virtual machine making an IO request and to determine a priority given to the IO request based on an identity of the virtual machine.

36. The computer system of claim 34, wherein the queue assignor unit comprises a virtual machine interface to receive an indication from guest software that an IO request requires a high priority.

37. The computer system of claim 34, wherein the queue assignor unit comprises a tag identifier unit to identify a priority requested for an IO request.