MULTILEVEL SUPPORT IN A NESTED VIRTUALIZATION ENVIRONMENT

• US 20120216187A1
• Filed: 02/17/2011
• Published: 08/23/2012
• Est. Priority Date: 02/17/2011
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Ben-Yehuda, Shmuel, Gordon, Abel, Yassour, Ben-Ami, Har'El, Nadav Yosef
• Granted Patent: US 8,490,090 B2
• Time in Patent Office: Days
• US Class Current: 718/1
• CPC Class Codes: G06F 2009/45566 Nested virtual machines
• CPC Class Codes: G06F 9/45558 Hypervisor-specific management and integration aspects

Abstract

A method of handling an event occurring in a nested virtualization computing environment is provided, wherein N hypervisors are executed nestedly, with a first hypervisor running at level zero (L0) directly over a host machine, and other hypervisors nestedly running at levels L1 to Ln, respectively. The method comprises trapping an event generated by software running at level Ln; determining a hypervisor x at level Lx designated for handling the trapped event; and wherein the hypervisor x emulates features needed for performing the trapped event for the software running at the level Ln.

Claims

1. A method of handling an event occurring in a nested virtualization computing environment, wherein N hypervisors are executed nestedly, with a first hypervisor running at level zero (L0) directly over a host machine, and other hypervisors nestedly running at levels L1 to Ln, respectively, the method comprising:

trapping an event generated by software running at level Ln;

determining a hypervisor x at level Lx designated for handling the trapped event; and

wherein the hypervisor x emulates features needed for performing the trapped event for the software running at the level Ln.

2. The method of claim 1 further comprising transforming the trapped event generated at the level Ln.

3. The method of claim 2 further comprising forwarding the trapped event to level Lx for handling.

4. The method of claim 3 further comprising identifying when level Lx resumes Lx+1.

5. The method of claim 4 further comprising propagating the changes at level Lx to apply to level Lx+1 through Ln.

6. The method of claim 5 further comprising resuming level Ln.

7. The method of claim 6, wherein level Ln is resumed instead of Lx+1.

8. The method of claim 1, wherein the hypervisor x is among a group of one or more hypervisors running at levels 0 to n designated for handling the trapped event.

9. The method of claim 8, wherein the hypervisor x is the highest ranking hypervisor in said group.

10. The method of claim 2, wherein the trapped event generated at the level Ln is transformed, if the event was caused by a lower level Lx+1, when x+1<

n.

11. A computer-implemented system for handling an event occurring in a nested virtualization computing environment, wherein N hypervisors are executed nestedly, with a first hypervisor running at level zero (L0) directly over a host machine, and other hypervisors nestedly running at levels L1 to Ln, respectively, the system comprising:

a logic code for trapping an event generated by software running at level Ln;

a logic code for determining a hypervisor x at the level Lx designated for handling the trapped event, wherein the hypervisor x is among a group of one or more hypervisors running at levels 0 to n designated for handling the trapped event and the hypervisor x is the highest ranking hypervisor in said group; and

wherein the hypervisor x emulates features needed for performing the trapped event for the software running on the hypervisor x at the level Ln.

12. The system of claim 11, wherein the trapped event generated at the level Ln is transformed, if the event was caused by a lower level Lx+1, when x+1<

n.

13. The system of claim 12 further comprising forwarding the trapped event to level Lx for handling.

14. The system of claim 13 further comprising identifying when level Lx resumes Lx+1.

15. The system of claim 14 further comprising propagating the changes at level Lx to apply to level Lx+1 through Ln.

16. The system of claim 15 further comprising resuming level Ln.

17. A computer readable storage medium for storing logic code executable on a computing machine, wherein execution of the logic code causes the computing machine to:

trap an event generated by software running at level Ln;

determine a hypervisor x at the level Lx designated for handling the trapped event, wherein the hypervisor x is among a group of one or more hypervisors running at levels 0 to n designated for handling the trapped event and the hypervisor x is the highest ranking hypervisor in said group; and

wherein the hypervisor x emulates features needed for performing the trapped event for the software running on the hypervisor x at the level Ln.

18. The computer readable storage medium of claim 17, wherein the trapped event generated at the level Ln is transformed, if the event was caused by a lower level Lx+1, when x+1<

n.

19. The computer readable storage medium of claim 18 wherein the trapped event is forwarded to level Lx for handling.

20. The computer readable storage medium of claim 19 wherein the changes at level Lx are propagated to apply to level Lx+1 through Ln, when level Lx resumes Lx+1.