SYSTEMS AND METHODS FOR MEMORY DEDUPLICATION BY DESTINATION HOST IN VIRTUAL MACHINE LIVE MIGRATION

• US 20150052323A1
• Filed: 08/16/2013
• Published: 02/19/2015
• Est. Priority Date: 08/16/2013
• Status: Active Grant

• Current Assignee: Red Hat Israel Ltd. (International Business Machines Corporation)
• Original Assignee: Red Hat Israel Ltd. (International Business Machines Corporation)
• Inventors: Noel, Karen, Tsirkin, Michael
• Granted Patent: US 9,459,902 B2
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 12/00 Accessing, addressing or allocating within memory systems or architectures digital input from, or digital output to record carriers, e.g. to disk storage units, G06F3/06
• CPC Class Codes: G06F 2009/4557 Distribution of virtual machine instances; Migration and load balancing
• CPC Class Codes: G06F 2009/45583 Memory management, e.g. access or allocation
• CPC Class Codes: G06F 9/4413 Plug-and-play [PnP]
• CPC Class Codes: G06F 9/45558 Hypervisor-specific management and integration aspects

Abstract

Systems and methods for memory de-duplication in a virtual machine undergoing live migration. An example method may comprise: receiving, by a hypervisor executing on a destination host computer system, a first virtual address and a corresponding physical memory range identifier, the physical memory range identifier identifying a first physical memory range on an origin host computer system, the first virtual address identifying a first virtual memory range mapped to the first physical memory range in a virtual address space of a first virtual machine undergoing live migration from the origin host computer system to the destination host computer system; identifying a second virtual address corresponding to the physical memory range identifier, the second virtual address identifying a second virtual memory range in a virtual address space of a second virtual machine undergoing live migration from the origin host computer system to the destination host computer system; identifying a destination physical address corresponding to the second virtual address, the destination physical address identifying a second physical memory range on the destination host computer system; and mapping, on the destination host computer system, the first virtual address to the destination physical address.

Claims

1. A method, comprising:

receiving, by a hypervisor executing on a destination host computer system, a first virtual address and a corresponding physical memory range identifier, the physical memory range identifier identifying a first physical memory range on an origin host computer system, the first virtual address identifying a first virtual memory range mapped to the first physical memory range in a virtual address space of a first virtual machine undergoing live migration from the origin host computer system to the destination host computer system;

identifying a second virtual address corresponding to the physical memory range identifier, the second virtual address identifying a second virtual memory range in a virtual address space of a second virtual machine undergoing live migration from the origin host computer system to the destination host computer system;

identifying a destination physical address corresponding to the second virtual address, the destination physical address identifying a second physical memory range on the destination host computer system; and

mapping, on the destination host computer system, the first virtual address to the destination physical address.

2. The method of claim 1, wherein identifying the second virtual address further comprises looking up the physical memory range identifier in a data structure comprising a plurality of memory mapping entries, each memory mapping entry mapping a virtual memory range to a physical memory range.

3. The method of claim 1, wherein the physical memory range identifier comprises at least one of a memory device identifier and a memory address on a memory device identified by the memory device identifier.

4. The method of claim 1, wherein the physical memory range identifier comprises a content identifier.

5. The method of claim 1, wherein the destination physical address comprises a memory device identifier and a memory address on a memory device identified by the memory device identifier.

6. The method of claim 1, wherein the first virtual machine and the second virtual machine are provided by the same virtual machine.

7. The method of claim 1, wherein the physical memory range comprises one or more physical memory pages.

8. The method of claim 1, wherein the first virtual memory range comprises one or more virtual memory pages.

9. The method of claim 1, wherein the second virtual memory range comprises one or more virtual memory pages.

10. The method of claim 1, further comprising:

detecting a modification, by a virtual machine, of a virtual memory page of the first virtual memory range;

copying, to a new physical memory page, a physical memory page corresponding to the virtual memory page; and

mapping, in the address space of the virtual machine, the virtual memory page to the new physical memory page.

11. A system comprising:

a memory; and

one or more physical processors, coupled to the memory, to;

receive a first virtual address and a corresponding physical memory range identifier, the physical memory range identifier identifying a first physical memory range on an origin host computer system, the first virtual address identifying a first virtual memory range mapped to the first physical memory range in a virtual address space of a first virtual machine undergoing live migration from the origin host computer system to a destination host computer system;

identify a second virtual address corresponding to the physical memory range identifier, the second virtual address identifying a second virtual memory range in a virtual address space of a second virtual machine undergoing live migration from the origin host computer system to the destination host computer system;

identify a destination physical address corresponding to the second virtual address, the destination physical address identifying a second physical memory range on the destination host computer system; and

map, on the destination host computer system, the first virtual address to the destination physical address.

12. The system of claim 11, wherein the processors are further to provide a data structure comprising a plurality of memory mapping entries, each memory mapping entry mapping a virtual memory range to a physical memory range.

13. The system of claim 11, wherein the physical memory range identifier comprises at least one of a memory device identifier and a memory address on a memory device identified by the memory device identifier.

14. The system of claim 11, wherein the physical memory range identifier comprises a content identifier.

15. The system of claim 11, wherein the destination physical address comprises a memory device identifier and a memory address on a memory device identified by the memory device identifier.

16. The system of claim 11, wherein the first virtual machine and the second virtual machine are provided by the same virtual machine.

17. The system of claim 11, wherein the physical memory range comprises one or more physical memory pages.

18. A computer-readable non-transitory storage medium comprising executable instructions that, when executed by a computer system, cause the computer system to:

receive a first virtual address and a corresponding physical memory range identifier, the physical memory range identifier identifying a first physical memory range on an origin host computer system, the first virtual address identifying a first virtual memory range mapped to the first physical memory range in a virtual address space of a first virtual machine undergoing live migration from the origin host computer system to a destination host computer system;

identify a second virtual address corresponding to the physical memory range identifier, the second virtual address identifying a second virtual memory range in a virtual address space of a second virtual machine undergoing live migration from the origin host computer system to the destination host computer system;

identify a destination physical address corresponding to the second virtual address, the destination physical address identifying a second physical memory range on the destination host computer system; and

map, on the destination host computer system, the first virtual address to the destination physical address.

19. The computer-readable non-transitory storage medium of claim 18, further comprising executable instructions causing the computer system to provide a data structure comprising a plurality of memory mapping entries, each memory mapping entry mapping a virtual memory range to a physical memory range.

20. The computer-readable non-transitory storage medium of claim 18, further comprising executable instructions causing the computer system to:

detect a modification, by a virtual machine, of a virtual memory page of the first virtual memory range;

copy, to a new physical memory page, a physical memory page corresponding to the virtual memory page; and

map, in the address space of the virtual machine, the virtual memory page to the new physical memory page.