Virtualization of input/output devices in a logically partitioned data processing system

• US 6,944,847 B2
• Filed: 05/02/2002
• Issued: 09/13/2005
• Est. Priority Date: 05/02/2002
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: McIntosh, Gordon D., Desai, Prakash Vinodrai
• Primary Examiner(s): Vo, Ted T.
• Application Number:
  US10/138,896
• Publication Number:
  US 20030208642A1
• Time in Patent Office: 1,230 Days
• Field of Search: 717100-103, 717120-127, 709223-226, 709/104, 710 5- 7, 714/56
• US Class Current: 717/121
• CPC Class Codes: G06F 2003/0697 device management, e.g. handlers, drivers, I/O schedulers
• CPC Class Codes: G06F 3/0601 Interfaces specially adapted for storage systems
• CPC Class Codes: G06F 3/0626 Reducing size or complexity of storage systems
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/0644 Management of space entities, e.g. partitions, extents, pools
• CPC Class Codes: G06F 3/0664 at device level, e.g. emulation of a storage device or system
• CPC Class Codes: G06F 3/0677 Optical disk device, e.g. CD-ROM, DVD
• 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 9/52 Program synchronisation; Mutual exclusion, e.g. by means of semaphores

Abstract

A hypervisor (management) layer synchronizes use of virtualized input/output (I/O) devices that may regularly be used by multiple partitions of a logically partitioned data processing system by making them callable by any system partition to the hypervisor layer. A partition makes a call to the hypervisor to reserve an I/O resource. If the I/O resource is presently allocated to another partition when a call is made to reserve the resource, the hypervisor rejects the request to reserve the device. If the resource is available, the hypervisor issues a command to the resource to service calls made from the reserving partition. After utilizing the resource as necessary, the reserving partition releases control over the I/O device and sends a notification to hypervisor that it has released the I/O device. Upon release, the I/O device will automatically be available for use by another partition via a call to the hypervisor.

Claims

1. A method of allocating an input/output adapter to a logical partition within a logically partitioned data processing system, the method comprising the steps of:

receiving a request from an operating system image assigned to the logical partition to be allocated the input/output adapter;

allocating the input/output adapter to the logical partition, in response to the request, such that the input/output adapter executes commands received from the logical partition; and

releasing the allocation of the input/output adapter to the logical partition such that the input/output adapter no longer executes commands received from the logical partition.

2. The method of claim 1, wherein the steps of allocating and releasing are performed only if the input/output adapter is not allocated to another logical partition.

3. The method of claim 1, wherein the input/output adapter provides connectivity between a CD ROM drive and the logically partitioned data processing system.

4. The method of claim 1, wherein the input/output adapter is not assigned to a partition of the plurality of partitions.

5. A computer program product for use in a data processing system for allocating an input/output adapter to a logical partition within a logically partitioned data processing system, the computer program product comprising:

a storage medium; and

program instructions stored on said storage medium for (a) receiving a request from an operating system image assigned to the logical partition to be allocated the input/output adapter, (b) allocating the input/output adapter to the logical partition, in response to the request, such that the input/output adapter executes commands received from the logical partition; and

(c) releasing the allocation of the input/output adapter to the logical partition such that the input/output adapter no longer executes commands received from the logical partition.

6. The computer program product of claim 5, wherein (b) and (c) are performed only if the input/output adapter is not allocated to another logical partition.

7. The computer program product of claim 5, wherein the input/output adapter provides connectivity between a CD ROM drive and the logically partitioned data processing system.

8. The computer program product of claim 5, wherein the input/output adapter is not assigned to a partition of the plurality of partitions.

9. A logically partitioned data processing system, comprising:

a plurality of logical partitions;

a plurality of operating systems, each assigned to one of said plurality of logical partitions;

a plurality of input/output adapters, each capable of being allocated to any one of said plurality of logical partitions, wherein an input/output adapter executes commands received from a logical partition to which it has been allocated; and

a management layer that allocates an input/output adapter of the plurality of input/output adapters to a logical partition of the plurality of logical partitions when a request is received from the operating system assigned to the logical partition, and wherein, upon completion of the logical partition'"'"'s utilization of the input/output adapter for a current allocation, the logical partition releases the input/output adapter to the management layer such that it becomes available for allocation to a logical partition of the plurality of logical partitions.

10. The system of claim 9, wherein the management layer will only allocate an input/output adapter if it is not currently allocated.

11. The system of claim 9, wherein the operating system releasing the input/output adapter sends a release notification to the management layer.

12. The system of claim 9, wherein at least one of the input/output adapters of the plurality of input/output adapters provides connectivity between a CD ROM drive and the logically partitioned data processing system.