METHOD AND SYSTEM FOR CROSS-DOMAIN DATA SHARING

• US 20090313446A1
• Filed: 06/12/2008
• Published: 12/17/2009
• Est. Priority Date: 06/12/2008
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Schuba, Christoph L., Levon, John B.
• Granted Patent: US 8,037,279 B2
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 12/0284 Multiple user address space allocation, e.g. using different base addresses interprocessor communication G06F15/163
• CPC Class Codes: G06F 12/109 for multiple virtual address spaces, e.g. segmentation G06F12/1036 takes precedence
• CPC Class Codes: G06F 2212/656 Address space sharing

Abstract

A method for sharing data between a first domain and a second domain, including issuing a first request for data from a storage pool by the first domain, receiving the first request by a control domain driver in a control domain, obtaining the data by the control domain driver, storing a first copy of the data in shared memory at a first physical address, updating a hypervisor page map to include an entry associating a first pseudo-physical page number with the first physical address, notifying the first domain that the first request has been completed, issuing a second request for the data by the second domain, receiving the second request by the control domain driver, determining that the first copy of the data is present in the shared memory, and updating the hypervisor page map to include an entry associating the second pseudo-physical page number with the first physical address.

Claims

1. A method for sharing data between a first domain and a second domain, comprising:

issuing a first request for data from a storage pool by the first domain, wherein the first request comprises a first pseudo-physical page number, wherein the first domain comprises a first domain address map, and wherein the first domain address map comprises an entry associating the first pseudo-physical page number with a first virtual memory address;

receiving the first request by a control domain driver in a control domain;

obtaining the data from the storage pool by the control domain driver;

storing a first copy of the data in shared memory at a first physical address, wherein the shared memory is accessible by the control domain, the first domain, and the second domain;

updating a hypervisor page map to include an entry associating the first pseudo-physical page number with the first physical address;

notifying the first domain that the first request has been completed;

issuing a second request for the data from the storage pool by the second domain, wherein the second request comprises a second pseudo-physical page number, wherein the second domain comprises a second domain address map, and wherein the second domain address map comprises an entry associating the second pseudo-physical page number with a second virtual memory address;

receiving the second request by the control domain driver in the control domain;

determining by the control domain driver that the first copy of the data is present in the shared memory;

updating the hypervisor page map to include an entry associating the second pseudo-physical page number with the first physical address; and

notifying the second domain that the second request has been completed,

wherein the first domain and second domain communicate with the control domain using a hypervisor.

2. The method of claim 1, further comprising:

issuing, to the control domain driver, a third request by the first domain to modify the copy of the data in shared memory;

intercepting the third request by the hypervisor;

creating a second copy of the data;

storing the second copy of the data in virtual memory allocated for the first domain at a second physical address;

updating the hypervisor page map to include an entry associating the second physical address with a third pseudo-physical page number;

updating the first domain address map to include an entry associating the third pseudo-physical page number with a third virtual address; and

completing the third request using the second copy of the data.

3. The method of claim 2,

wherein the data is accessible to the control domain using the file system;

wherein the data is accessible to the second domain using a second clone of the file system;

wherein the second copy of the data is accessible to the first domain using the first clone of the file system;

wherein the data is not accessible to the first domain; and

wherein the data is one selected from a group consisting of a file and a portion of a file.

4. The method of claim 3,

wherein the control domain, the first domain, and the second domain execute on a host computer comprising main memory and operatively connected to the storage pool;

wherein the main memory comprises the shared memory and the virtual memory allocated for the first domain; and

wherein the file system, the first clone of the file system, and the second file system are stored in the storage pool.

5. The method of claim 3, wherein the file system, the first clone of the file system, and the second file system are copy-on-write file systems.

6. The method of claim 1, further comprising:

updating a reference count associated with the first physical address to indicate that two domains reference the first physical address.

7. The method of claim 1,

wherein the data is accessible to the control domain associated with the file system;

wherein the data is accessible to the first domain using the first clone of the file system;

wherein the data is accessible to the second domain using the second clone of the file system; and

wherein the data is one selected from a group consisting of a file and a portion of a file.

8. The method of claim 7,

wherein the control domain, the first domain, and the second domain execute on a host computer comprising main memory and operatively connected to the storage pool;

wherein the main memory comprises the shared memory and the virtual memory allocated for the first domain; and

wherein the file system, the first clone of the file system, and the second file system are stored in the storage pool.

9. The method of claim 8, wherein the file system, the first clone of the file system, and the second file system are copy-on-write file systems.

10. The method of claim 1, wherein the first domain executes a first type of operating system and the second domain executes a second type of operating system.

11. A computer readable medium comprising instructions executable by a processor for performing a method, the method comprising:

issuing a first request for data from a storage pool by a first domain, wherein the first request comprises a first pseudo-physical page number, wherein the first domain comprises a first domain address map, and wherein the first domain address map comprises an entry associating the first pseudo-physical page number with a first virtual memory address;

receiving the first request by a control domain driver in a control domain;

obtaining the data from the storage pool by the control domain driver;

storing a first copy of the data in shared memory at a first physical address, wherein the shared memory is accessible by the control domain, the first domain, and a second domain;

updating a hypervisor page map to include an entry associating the first pseudo-physical page number with the first physical address;

notifying the first domain that the first request has been completed;

issuing a second request for the data from the storage pool by the second domain, wherein the second request comprises a second pseudo-physical page number, wherein the second domain comprises a second domain address map, and wherein the second domain address map comprises an entry associating the second pseudo-physical page number with a second virtual memory address;

receiving the second request by the control domain driver in the control domain;

determining by the control domain driver that the first copy of the data is present in the shared memory;

updating the hypervisor page map to include an entry associating the second pseudo-physical page number with the first physical address; and

notifying the second domain that the second request has been completed,

wherein the first domain and second domain communicate with the control domain using a hypervisor.

12. The computer readable medium of claim 11, further comprising instructions executable by the processor for performing the method, the method further comprising:

issuing, to the control domain driver, a third request by the first domain to modify the copy of the data in shared memory;

intercepting the third request by the hypervisor;

creating a second copy of the data;

storing the second copy of the data in virtual memory allocated for the first domain at a second physical address;

updating the hypervisor page map to include an entry associating the second physical address with a third pseudo-physical page number;

updating the first domain address map to include an entry associating the third pseudo-physical page number with a third virtual address; and

completing the third request using the second copy of the data

13. The computer readable medium of claim 12,

wherein the data is accessible to the control domain using the file system;

wherein the data is accessible to the second domain using a second clone of the file system;

wherein the second copy of the data is accessible to the first domain using the first clone of the file system;

wherein the data is not accessible to the first domain; and

wherein the data is one selected from a group consisting of a file and a portion of a file.

16. The computer readable medium of claim 11, further comprising instructions executable by the processor for performing the method, the method further comprising:

updating a reference count associated with the first physical address to indicate that two domains reference the first physical address.

17. The computer readable medium of claim 11,

wherein the data is accessible to the control domain using the file system;

wherein the data is accessible to the first domain using the first clone of the file system;

wherein the data is accessible to the second domain using the second clone of the file system; and

wherein the data is one selected from a group consisting of a file and a portion of a file.

18. The computer readable medium of claim 17,

wherein the control domain, the first domain, and the second domain execute on a host computer comprising main memory and operatively connected to the storage pool;

wherein the main memory comprises the shared memory and the virtual memory allocated for the first domain;

wherein the file system, the first clone of the file system, and the second file system are stored in the storage pool; and

wherein the file system, the first clone of the file system, and the second file system are copy-on-write file systems.

14. The computer readable medium of claim 14,

wherein the control domain, the first domain, and the second domain execute on a host computer comprising main memory and operatively connected to the storage pool;

wherein the main memory comprises the shared memory and the virtual memory allocated for the first domain; and

wherein the file system, the first clone of the file system, and the second file system are stored in the storage pool.

15. The computer readable medium of claim 14, wherein the file system, the first clone of the file system, and the second file system are copy-on-write file systems.

19. A system, comprising:

a processor;

main memory comprising shared memory;

a storage pool, wherein the storage pool comprises instructions executable by the processor to perform a method, the method comprising;

issuing a first request for data from a storage pool by a first domain, wherein the first request comprises a first pseudo-physical page number, wherein the first domain comprises a first domain address map, and wherein the first domain address map comprises an entry associating the first pseudo-physical page number with a first virtual memory address;

receiving the first request by a control domain driver in a control domain;

obtaining the data from the storage pool by the control domain driver;

storing a first copy of the data in the shared memory at a first physical address, wherein the shared memory accessible by the control domain, the first domain, and a second domain;

updating a hypervisor page map to include an entry associating the first pseudo-physical page number with the first physical address;

notifying the first domain that the first request has been completed;

issuing a second request for the data from the storage pool by the second domain, wherein the second request comprises a second pseudo-physical page number, wherein the second domain comprises a second domain address map, and wherein the second domain address map comprises an entry associating the second pseudo-physical page number with a second virtual memory address;

receiving the second request by the control domain driver in the control domain;

determining by the control domain driver that the first copy of the data is present in the shared memory;

updating the hypervisor page map to include an entry associating the second pseudo-physical page number with the first physical address; and

notifying the second domain that the second request has been completed,

wherein the first domain and second domain communicate with the control domain using a hypervisor.

20. The system of claim 19,

wherein the data is accessible to the control domain using the file system;

wherein the data is accessible to the first domain using the first clone of the file system;

wherein the data is accessible to the second domain using the second clone of the file system;

wherein the data is one selected from a group consisting of a file and a portion of a file;

wherein the file system, the first clone of the file system, and the second file system are stored in the storage pool; and

wherein the file system, the first clone of the file system, and the second file system are copy-on-write file systems.