International Business Machines Corporation

Hans-Helge Lehmann

Harry M Yudenfriend

Charles E Shapley

Charles W Gainey, Jr

Jeffrey Paul Kubala

Kenneth J Oakes

Leslie W Wyman

Frank William Brice

Tan Lu

Marten J Halma

Janet R Easton

John S Trotter

Steven G Glassen

Beth A Glendening

Allan Samuel Meritt

Robert A Smith

Dale Francis Riedy, Jr

Christoph Raisch

Gustav E Sittmann, Iii

William J Rooney

Scott M Carlson

Eugene P Hefferon

Michael Jung

Elke G Nass

Ugochukwu Njoku-Charles

David W Hollar

Ugochukwo Njoku-Charles

Michael G Melendy

A configuration adaptation layer (CAL) for I/O devices such as I/O adapters is provided. This configuration adaptation layer (CAL) explicitly provides a mapping between adapter functions and adapter resources in a way such that it is senseable in-band by the computer system using the adapter, e.g., by a virtual machine monitor.

Configuration adaptation layer for mapping I/O device resources

An input/output subsystem is configured as a plurality of input/output subsystem images, each of which appears to a program as an independent input/output subsystem. An input/output subsystem image is identified by an input/output subsystem image identifier, which is used by various programs to designate the particular input/output subsystem image for which an I/O operation is to be performed. An input/output subsystem image includes, for instance, one or more input/output paths. An input/output path of an input/output subsystem image is identified by an input/output path identifier, as well as a physical input/output path identifier.

Multiple logical input/output subsystem facility

Input/output (I/O) communications subadapters, such as subchannels, of an I/O subsystem are dedicated to components, such as I/O devices, of the I/O subsystem. The subadapters provide information about the associated components, in response to the execution of I/O instructions. To enhance I/O connectivity, a plurality of sets of I/O subadapters is provided to an operating system image. This allows programs of the operating system image to access a same component via different sets of I/O communications subadapters. Further, it enables an operating system image to use more than 64 k subchannels.

Managing sets of input/output communications subadapters of an input/output subsystem

A communications adapter is shared by a plurality of input/output (I/O) subsystem images of an I/O subsystem of a central processing complex. To enable the sharing, the communications adapter is configured to a plurality of I/O paths of the plurality of I/O subsystem images. An I/O subsystem may have one or more shared communications adapters.

Sharing communications adapters across a plurality of input/output subsystem images

An input/output subsystem of a computing environment is configured as a plurality of input/output subsystem images, each of which appears to a program as an independent input/output subsystem. An input/output subsystem image includes one or more communications adapters used for communicating within the computing environment. A communications adapter is identified by hardware of the computing environment by using a first identifier, and it is identified by a program of the computing environment by using a second identifier. The identifiers can be of different sizes.

Method, system and program products for identifying communications adapters of a computing environment

An input/output subsystem is configured as a plurality of input/output subsystem images, each of which appears to a program as an independent input/output subsystem. An input/output subsystem image is identified by an input/output subsystem image identifier, which is used by various programs to designate the particular input/output subsystem image for which an I/O operation is to be performed. An operating system is provided with access to a plurality of input/output subsystem images of the input/output subsystem. One or more controls are provided to the operating system image to enable the operating system image to access the plurality of input/output subsystem images.

Method, system and program products for enhancing input/output processing for operating system images of a computing environment

A method and system for flexibly and efficiently assigning channel path identifiers (CHPIDs) used by operating system software in computer systems to identify the communication path to I/O devices via channels. To avoid wasted CHPIDs, which may be limited in number, CHPIDs are assigned only to channels which are installed on and configured to the computer system. The CHPIDs may be re-assigned concurrently with ongoing system operations via a user interface and/or an imported, pre-defined CHPID mapping.

Method and system for flexible channel path identifier assignment

A method and apparatus for determining common usage of elements among at least two channels in a data processing system having an arbitrary hardware element hierarchy including multiple channel paths over which data is transmitted. An internally executed initialization program builds a bit mask for channel paths to be compared wherein the bit masks describe the hierarchy of the hardware elements in the channel paths to be compared. A compare program provides a comparison result whose value reflects the impact of the failure of hardware elements that are common to the channel path being compared. The comparison results contains multiple bits, with set bits representing each element which is common to the hardware element common to the channel paths being compared. The impact of a failure of a common hardware element is greater the more significant the bit position of that component resides in the comparison results.

Determination of the degree of common usage for elements of a data processing system

Growing community of inventors

Weil im Schoenbuch, Germany

Hans-Helge Lehmann