Protocol for communication with a user-mode device driver

• US 20060253859A1
• Filed: 04/21/2005
• Published: 11/09/2006
• Est. Priority Date: 04/21/2005
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Sankaranarayan, Mukund, Patrick, Stuart R., Dai, Chung Lang
• Granted Patent: US 7,603,484 B2
• Time in Patent Office: Days
• US Class Current: 719/321
• CPC Class Codes: G06F 9/4413 Plug-and-play [PnP]
• CPC Class Codes: G06F 9/545 where tasks reside in different layers, e.g. user- and kernel-space

Abstract

A user-mode device driver architecture is provided by the subject invention. The architecture includes a reflector, a driver manager and a host process which hosts and isolates one or more user-mode device driver(s). The user-mode device driver runs in the user-mode (UM) environment and has access to various UM services. The reflector resides in “kernel memory” (e.g., memory/resource(s) available to operating system) while the driver manager, host process and user mode device driver(s) are located in user space (e.g., memory/resource(s) available to user application(s)). The reflector provides a secure, stable communication path for application(s), the host process and/or user-mode device driver(s) to communicate with the operating system. The reflector can redirect input/output (I/O) request(s) from application(s) to the user-mode device driver(s) via the host process. The driver manager can create the host process (e.g., in response to a request from the reflector), track information about the host process and/or destroy the host process (e.g., in response to a request from the reflector).

Claims

1. A user-mode device driver architecture comprising:

a host process that hosts and isolates one or more user-mode device drivers; and

,

a reflector that operates in kernel memory and exchanges a message with the user-mode device driver via the host process.

2. The architecture of claim 1, the message exchanged between the reflector and the host process comprising an LPC message.

3. The architecture of claim 2, the message associated with a corresponding I/o request from an application, PnP/Power events from the system, or IO cancellation events from an application or the system.

4. The architecture of claim 1, further comprising a driver manager control object that operates in kernel memory, the driver manager control object facilitates communication from the driver manager to the reflector.

5. The architecture of claim 1, further comprising a host process control object that operates in kernel memory, the host process control object facilitates communication from the host process to the reflector.

6. The architecture of claim 1, the reflector comprising an up device object employed to send a message to the user-mode device driver.

7. The architecture of claim 1, the reflector comprising a down device object employed to receive a message from the user-mode device driver, the message further provided to a kernel driver that performs low-level functionality in kernel memory.

8. The architecture of claim 1, the driver manager runs as a service of an operating system.

9. The architecture of claim 1, the driver manager tracks information associated with the host process.

10. The architecture of claim 1, the driver manager can remove the host process in response to a request from the reflector.

11. The architecture of claim 1, the user-mode device driver is instantiated by the host process.

12. The architecture of claim 1, further comprising a driver manager that instantiates the host process based, at least in part, upon a request from the reflector.

13. The architecture of claim 1, the reflector provides a plug and play request message to the host process.

14. The architecture of claim 13, the plug and play request message associated with at least one of a start device message, a query remove device message, a remove device message, a cancel remove device message, a stop device message, a query stop device message, a cancel stop device message, a query device relations message, a query interface message, a query capabilities message, a query resources message, a query resources requirements message, a query device text message, a query filter resource requirements message, a read configuration message, a write configuration message, an eject message, a set lock message, a query ID message, a query PNP device state message, a query bus information message, a device usage notification message, a surprise removal message, a query proximity domain message, a wait wake message, a power sequence message, a set power message, and, a query power message.

15. The architecture of claim 1, the reflector provides a file I/O request message to the host process.

16. The architecture of claim 15, the file I/O request message comprising at least one of a create message, a cleanup message, a close message, a read message, a write message, an IO control message, and IO cancellation message.

17. A method of initializing a user-mode device driver architecture comprising:

creating a host process in user mode in response to an add device message received from an operating system, the host process hosts and isolates one or more user-mode device drivers;

initializing the host process;

establishing a communication connection between a reflector in kernel mode and the host process; and

,

building a user-mode device stack associated with the one or more user-mode device drivers.

18. The method of claim 17, further comprising at least one of the following:

detecting that a device has been added to a system;

notifying the reflector of the process ID of the host process; and

,

receiving a start message from the operating system.

19. A computer readable medium having stored thereon computer executable instructions for carrying out the method of claim 17.

20. A data packet transmitted between two or more computer components that facilitate communication between a reflector in kernel mode and a user-mode device driver, the data packet comprising:

an LPC message corresponding to an I/O request from an application, the LPC message generated by the reflector in kernel mode.