Systems and methods for supporting device access from multiple operating systems

• US 20060206904A1
• Filed: 03/11/2005
• Published: 09/14/2006
• Est. Priority Date: 03/11/2005
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Nicholas, Andrew Ernest, Watkins, Douglas A.
• Granted Patent: US 7,581,229 B2
• Time in Patent Office: Days
• US Class Current: 719/321
• CPC Class Codes: G06F 9/45537 Provision of facilities of other operating environments, e.g. WINE I/O emulation G06F13/105

Abstract

A host operating system can take ownership of a device. The host can project the presence of a device proxy (VDP) into a guest operating system. The VDP provides a set of device functions corresponding to the particular device class. Interactions with the VDP in the guest are forwarded to a Virtual Service Provider (VSP) in the host. The VSP maps a set of device class functions onto physical devices through a hardware abstraction and emulation layer. Functions supported directly by a physical device can be delivered to the device by the hardware abstraction layer (HAL). Functions not directly supported can be implemented through the hardware emulation layer (HEL). A uniform and robust set of functions may be made available in the guest regardless of hardware changes in the host, migration to a new host, or use of the device by other competing operating systems.

Claims

1. A computer system comprising:

a first operating system;

a second operating system;

a hardware device controllable from said first operating system via a driver installed on said first operating system;

a service provider in said first operating system for determining at least one function available from said hardware device;

a proxy driver configurable by said service provider to represent said at least one function of said hardware device to the second operating system.

2. The computer system of claim 1, further comprising a hardware abstraction and emulation layer between said service provider and said driver installed on said first operating system, wherein the hardware abstraction and emulation layer provides a first plurality of functions that are directly supported by the hardware device, and a second plurality of functions that require execution of software to carry out substantial aspects of a corresponding request.

3. The computer system of claim 1 wherein said a proxy driver is configurable by said service provider to represent said at least one function of said hardware device to a plurality of operating systems.

4. The computer system of claim 1 wherein the service provider maintains a state of the hardware device on behalf of the second operating system.

5. The computer system of claim 1 wherein the service provider comprises a component for determining if the hardware device is exchanged for a second hardware device.

6. The computer system of claim 1, further comprising a network connection to a second computer system, wherein said second operating system can be migrated across said network connection to said second computer system while maintaining a set of driver commands at said first operating system on behalf of said second operating system.

7. A computer readable medium bearing instructions for representing by a first operating system a hardware device in a second operating system, said instructions comprising:

instructions for determining by said first operating system at least one function available from said hardware device;

instructions for configuring by said first operating system a proxy driver to represent said at least one function of said hardware device to said second operating system;

instructions for receiving at said first operating system a request from said proxy driver to perform said at least one function;

instructions for communicating by said first operating system to a device driver installed on said first operating system for the purpose of carrying out said request.

8. The computer readable medium of claim 7 wherein said instructions for communicating by said first operating system to a device driver comprise instructions for requesting a hardware abstraction and emulation layer to perform the function, wherein the hardware abstraction and emulation layer provides a first plurality of functions that are directly supported by the hardware device, and a second plurality of functions that require execution of software to carry out substantial aspects of a corresponding request.

9. The computer readable medium of claim 7, further comprising instructions for configuring by said first operating system a proxy driver to represent said at least one function of said hardware device to a plurality of operating systems.

10. The computer readable medium of claim 7, further comprising instructions for maintaining by said first operating system a state of the hardware device on behalf of the second operating system.

11. The computer readable medium of claim 7, further comprising instructions for determining if the hardware device is exchanged for a second hardware device.

12. The computer readable medium of claim 7 wherein said instructions for communicating remain operable when said second operating system is migrated from a first computer system to a second computer system.

13. The computer readable medium of claim 7, further comprising instructions for switching by said first operating system from the use of said hardware device to the use of a second hardware device.

14. A method for representing by a first operating system a hardware device in a second operating system, comprising:

determining by said first operating system at least one function available from said hardware device;

configuring by said first operating system a proxy driver to represent said at least one function of said hardware device to said second operating system;

receiving at said first operating system a request from said proxy driver to perform said at least one function;

communicating by said first operating system to a device driver installed on said first operating system for the purpose of carrying out said request.

15. The method of claim 14 wherein said communicating by said first operating system to a device driver comprises requesting a hardware abstraction and emulation layer to perform the function, wherein the hardware abstraction and emulation layer provides a first plurality of functions that are directly supported by the hardware device, and a second plurality of functions that require execution of software to carry out substantial aspects of a corresponding request.

16. The method of claim 14, further comprising configuring by said first operating system a proxy driver to represent said at least one function of said hardware device to a plurality of operating systems.

17. The method of claim 14, further comprising maintaining by said first operating system a state of the hardware device on behalf of the second operating system.

18. The method of claim 14, further comprising determining if the hardware device is exchanged for a second hardware device.

19. The method of claim 14 wherein said communicating occurs despite a concurrent migration of said second operating system from a first computer system to a second computer system.

20. The method of claim 14, further comprising switching by said first operating system from using said hardware device to using a second hardware device.