Hypervisor to I/O Stack Conduit in Virtual Real Memory

• US 20090307396A1
• Filed: 06/09/2008
• Published: 12/10/2009
• Est. Priority Date: 06/09/2008
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Wang, James Y., Rosas, Morgan J., Nogueras, Jorge R.
• Granted Patent: US 9,208,003 B2
• Time in Patent Office: Days
• US Class Current: 710/65
• CPC Class Codes: G06F 2009/45579 I/O management, e.g. providing access to device drivers or storage
• CPC Class Codes: G06F 9/45558 Hypervisor-specific management and integration aspects
• CPC Class Codes: G06F 9/5077 Logical partitioning of resources; Management or configuration of virtualized resources specific details on emulation or internal functioning of virtual machines G06F9/455
• CPC Class Codes: G06F 9/541 via adapters, e.g. between incompatible applications
• CPC Class Codes: G06F 9/545 where tasks reside in different layers, e.g. user- and kernel-space

Abstract

Provided is conduit configured such that a hypervisor does not need to include logic for communicating directly with an I/O storage device. A virtual Asynchronous Service Interface (VASI) is the interface between a Command/Response Queue (CRQ), which receives CRQ commands from the hypervisor, and a Common Data-Link Interface (CDLI) of a Forwarder. The Forwarder receives I/O commands in a format associated with the CDLI and converts the commands into a generic I/O format understood by a Virtual Block Storage Device (VBSD). The reformatted command is transmitted to the VBSD, which issues commands to the native I/O stack. The hypervisor sends a read or write (R/W) request Lo the VASI, which passes the request to the Forwarder. The Forwarder converts the request and transmits the converted request to the VBSD. The VBSD transmits the request to the block storage device and returns the response to the Forwarder. The Forwarder replies to the request from the VASI with the response from the ABSD. The VASI then responds to the hypervisor. Also provided is an operation-specific module responsible for understanding and the intelligent processing of data that is transmitted between the hypervisor and the I/O stack.

Claims

1. A method for handling a request from a hypervisor in a computing system, comprising:

receiving, at a virtual asynchronous services interface (VASI) from a hypervisor, a request directed to a service provider device;

converting the request to a command data-link interface (CDLI) format;

transmitting the CDLI formatted request to an operation-specific module;

converting the CDLI formatted request to a format corresponding to the service provider device;

transmitting the service provider device formatted request to the service provider device;

receiving a response from the service provider device at the operation-specific module;

converting the response from the service provider device to the CDLI format;

transmitting the CDLI formatted response to the VASI;

converting the CDLI formatted response to a format corresponding to the hypervisor; and

transmitting the hypervisor formatted response to the hypervisor.

2. The method of claim 1, wherein the operation-specific device is a paging device and the service provider device is a virtual block storage device (VBSD).

3. The method of claim 1, wherein the operation-specific device is a hibernation module.

4. The method of claim 1, wherein the request is a Read/Write (R/W) operation.

5. The method of claim 1, further comprising processing the request received at the operation-specific module based upon a content type of the CDLI formatted request.

6. The method of claim 5, wherein the content type is a paging Input/Output (I/O) request.

7. The method of claim 6, the processing comprising:

a caching process;

a read-ahead process; and

an I/O coalescing process.

8. A system for handling a request from a hypervisor in a computing system, comprising:

a processor;

a hypervisor;

a virtual asynchronous services interface (VASI);

an operation-specific module;

logic, executed on the processor, for converting a request from the hypervisor to a command data-link interface (CDLI) format for transmission to the VASI;

logic, executed on the processor, for converting the CDLI formatted request to a format corresponding to the service provider device for transmission to the service provider device;

logic, executed on the processor, for converting a response from the service provider device to the CDLI format for transmission from the service provider device to the VASI; and

logic, executed on the processor, for converting the CDLI formatted response to a format corresponding to the hypervisor for transmission to the hypervisor.

9. The system of claim 8, wherein the operation-specific device is a paging device and the service provider device is a virtual block storage device (VBSD).

10. The system of claim 8, wherein the operation-specific device is a hibernation module.

11. The system of claim 8, wherein the request is a Read/Write (R/W) operation.

12. The system of claim 8, further comprising logic, executed on the processor, for processing the request received at the operation-specific module based upon a content type of the CDLI formatted request.

13. The system of claim 12, wherein the content type is a paging Input/Output (I/O) request.

14. The system of claim 13, the logic for processing comprising:

a caching process;

a read-ahead process; and

an I/O coalescing process.

15. A computer programming product for handling a request from a hypervisor in a computing system, comprising:

a physical memory;

logic, stored on the memory for execution on a processor, for;

receiving, at a virtual asynchronous services interface (VASI) from a hypervisor, a request directed to a service provider device;

converting the request to a command data-link interface (CDLI) format;

transmitting the CDLI formatted request to an operation-specific module;

logic, stored on the memory for execution on a processor, for converting the CDLI formatted request to a format corresponding to the service provider device;

transmitting the service provider device formatted request to the service provider device;

receiving a response from the service provider device at the operation-specific module;

converting the response from the service provider device to the CDLI format;

transmitting the CDLI formatted response to the VASI;

converting the CDLI formatted response to a format corresponding to the hypervisor; and

transmitting the hypervisor formatted response to the hypervisor.

16. The computer programming product of claim 15, wherein the operation-specific device is a paging device and the service provider device is a virtual block storage device (VBSD).

17. The computer programming product of claim 15, wherein the request is a Read/Write (R/W) operation.

18. The computer programming product of claim 15, further comprising logic for processing the request received at the operation-specific module based upon a content type of the CDLI formatted request.

19. The computer programming product of claim 18, wherein the content type is a paging Input/Output (I/O) request.

20. The computer programming product of claim 19, the logic for processing comprising:

a caching process;

a read-ahead process; and

an I/O coalescing process