Abstract: Input/output (I/O) measurement facilities are provided. An extended I/O measurement block facility is provided that enables measurement blocks to be stored in discontiguous areas of main storage and to be accessed directly via addresses. In a further aspect, an extended I/O measurement word facility is provided that facilitates the obtaining of measurement data for single I/O operations.

Abstract: 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.

Abstract: 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. In response to an operating system image submitting an input/output (I/O) request requesting access to an input/output subsystem image, a determination is made as to whether the operating system image is authorized to access the input/output subsystem image. In response to the access being authorized, the I/O request is authorized.

Abstract: 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.

Abstract: 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.

Abstract: Input/output interruptions are managed in computing environments that do not use dedicated per-guest interruption hardware to present interruptions. Dispatchable guest programs in the environment receive I/O interruptions directly without hypervisor intervention. This is facilitated by using one or more interruption controls stored in memory and associated with each guest program. For those guest programs that are not currently dispatchable, interruptions can be posted for the guests and notifications to the hypervisor can be aggregated. The hypervisor can then process a plurality of notifications for the plurality of guests in a single invocation.

Abstract: Method and means to provide a mechanism by which a hypervisor can permit a real machine to interpretively execute certain I/O instructions independently of the value of an I-bit in the subchannel. This is necessary as the I-bit covers all I/O instructions that can be interpretively executed; however, there can be instances where the hypervisor cannot allow the interpretive execution of other I/O instructions but can permit the interpretive execution of the SIGA instruction.

Abstract: Asynchronous requests, such as input/output (I/O) requests, within a coprocessor of a computing environment are managed. The management of the asynchronous requests is based on priorities associated with the asynchronous requests. This management includes, for instance, selecting an asynchronous request to be processed using a priority scheme, and/or affording resources to the asynchronous requests using a priority scheme.

Abstract: Asynchronous requests, such as input/output (I/O) requests, within a coprocessor of a computing environment are managed. The management of the asynchronous requests is based on priorities associated with the asynchronous requests. This management includes, for instance, selecting an asynchronous request to be processed using a priority scheme, and/or affording resources to the asynchronous requests using a priority scheme.

Abstract: A method and an apparatus for simulation of data in a computing system environment having a controlling program, a main memory, a plurality of hosts, at least one adapter and a queued-direct input/output device using a queued-direct input/output protocol. A pageable virtual machine is provided under control of a virtual-machine hypervisor in processing communication with one or more hosts. Simulation is then provided by strictly separating a set of protocol control blocks between those that contain main-memory addresses and those that do not. Copies of those control blocks that contain main-memory addresses is created and their addresses converted by the hypervisor from addresses used by the program in its virtual machine to real-memory addresses usable by the adapter.

Abstract: A method and an apparatus for timely and accurate processing of data in a network computing environment controlled by a running program and having a queuing mechanism established in a main storage. The main storage is in processing communication with an interface element having one or more adapters. At least one set of queues in the queuing mechanism is designated for input and another set for output. A signal adapter instruction can be issued to provide initiative to check content of any or all queues in the mechanism. With the help of the signal adapter an initiate-output can be specified when appropriate and the associated adapter can then asynchronously process the input or the output queues. A synchronize option is also available to signal the associated data queues to update all entries in order to render them current as observed by both the adapter and the controlling running program.

Abstract: A computer program device and product is provided for timely processing of data. The computer program device comprises a program storage device readable by a digital processing apparatus and a program means including instructions executable by the digital processing apparatus by designating at least one set of queues in the queuing mechanism as input queues and another as output queues; issuing a signal adapter instruction to provide initiative to check content of any or all queues in the queuing mechanism; specifying initiate-output or initiate-input appropriately by means of said signal adapter instruction to cause associated adapter to asynchronously process said output or input queues; and causing synchronization by means of said signal adapter instruction by signaling the associated data queues to update all entries in order to render them current.

Abstract: A method and apparatus for exchanging data in a network computing system having a main storage capable of connecting to at least one application server and an interface element with at least one adapter capable of establishing processing communication with at least one application user(s). A state change signalling protocol is used for transfer of data between the main storage and said adapter. In addition a queuing mechanism is established in the main storage having a plurality of queues each with a plurality of buffers. Some of these queues are dedicated to be input and others as output queues. By applying the protocol each input and output data buffer is associated with each of the active input and output queues. In this manner the input and output buffers are managed by placing the buffers into various states which are maintained in a special location that is set aside and is associated with each buffer.

Abstract: A method for specifying devices able to handle device requests in a computing network environment comprising a main memory having a queuing mechanism with a plurality of queues in processing communication with an adapter and a plurality of devices and/or processors. The format and attributes of devices in said the environment is determined as well as the size and attributes of the queues. When a request for data processing is received from at least one input/output device capable of attaching to the computing environment, the characteristics of any processors or device capable of processing the data is determined. A special store subchannel command is issued specifying which device or processor the request can be sent to after analyzing all information about the size, characteristics and attributes previously gathered. In this way information is provided about which processor or device can process the information using the special store subchannel command.

Abstract: A computer program device and an apparatus for proper processing of data requests. The apparatus determines which device is able to handle data requests in a computing network environment comprising a main memory having a queuing mechanism with a plurality of queues in processing communication with an adapter and a plurality of devices and/or processors. The format and attributes of devices in said the environment is determined as well as the size and attributes of the queues. When a request for data processing is received from at least one input/output device capable of attaching to the computing environment, the characteristics of any processors or device capable of processing the data is determined. A special store subchannel command is issued specifying which device or processor the request can be sent to after analyzing all information about the size, characteristics and attributes previously gathered.

Abstract: A method and an apparatus for controlling movement of data between any host and any network including a set of devices in a computing system environment having a main memory with a queuing mechanism having a plurality of queues capable of being shared between a plurality of independent processes running on at least one host and at least one I/O adapter. A finite-state machine (FSM) is provided in the main memory and the FSM is divided into two disjoint sets of states, one of which represents state-values processed by the host and set by the adapter, and said other set represents state-values processed by the adapter and set by said host. Using each of these set of states free-running, non-deadlocking processes are provided within the host and the adapter so that the processes sequence circularly and continuously through a vector related to the FSMs.

Abstract: A method and apparatus for error detection in a network computing system having a main storage capable of connecting to at least one application server and an interface element with at least one adapter capable of establishing processing communication with at least one application user(s). Data is transferred across the interface element to and from the main storage. The main storage includes a queuing mechanism providing a plurality of queuing components having attributes of devices to and from which data is to be transferred or received as well as information about the queuing mechanism itself. As part of the queuing component, providing a Storage-List-State Block (SLSB) having state indicators that provide state information about a plurality of buffers that make up each queue. A plurality of Error States is defined for by the SLSB Status Block. These Error States are set in the SLSB each time the interface element detects errors in the data stream.

Abstract: Enables any OS of plural OSs within any of plural logical-resource partitions (LPARs) of a CEC to use interpretive execution for synchronously-executable CHSC (channel subsystem call) commands. A CHSC command authorization mask (CCAM) is provided to control which CHSC commands are allowed to execute interpretively (with pass-through), and which commands are executed with hypervisor intervention (as all prior CHSC commands did). By enabling interpretive execution of those commands which can successfully operate with pass-through, significant system efficiency is obtained. And by disabling interpretive execution for a subset of CHSC commands (which are not allowed to execute with pass-through) potential system failures may be prevented. Thus, interpretive execution may be restricted differently among the OSs in a CEC. Novel CHSC command execution now handles multiple images of shared I/O resources by use of image identifiers, which could not be done before.

Abstract: Enables an I/O channel program to use IDAWs (indirect data address words) to control data transfers from/to an I/O (input/output) device to/from either or both of ES (expanded storage) and/or system MS (main storage), in which data moved to/from ES does not move through MS. ES and MS are plural electronic storage media in a data processing system, and the I/O device is any I/O device selectable by the system. Intermixing of data transfers between ES and MS may be controlled by a single IDAW list accessed by a channel control word (CCW) in a channel program in a data transfer direction indicated in the CCW without any channel mode change.

Abstract: This invention involves reconfiguration support for shared I/O resources in a a computer electronic complex (CEC) supporting both shared and unshared I/O channels of the type described and claimed in U.S. patent application Ser. No. 07/898,867 (PO9-92-016) filed on the same day as the subject application and assigned to the same assignee as the subject application. Prior channel subsystem call (CHSC) instructions cannot execute when a channel is to be configured as shareable by plural operating systems in a CEC.