Abstract: Processing multicast messages in a data processing system that includes compute nodes, each of which includes a communications controller, the communications controllers operatively coupled for data communications amongst the compute nodes, each compute node in the data processing system executing at least one logical partition, the data processing system including a hypervisor, where multicast messages are processed by receiving, by more than one of the communications controllers, a multicast message; responsive to receipt of the multicast message, signaling, by one of the communications controllers, an interrupt in the hypervisor without signaling an interrupt by any other communications controller; determining, by the hypervisor, that the message received by the interrupt signaling communications controller is a multicast message; and providing, by the hypervisor, the multicast message to at least one logical partition configured to receive multicast messages.

Abstract: Data communications through a host Fibre Channel adapter (‘HFCA’) implemented with a computer that includes two or more logical partitions, each logical partition including a separate instance of an operating system, each instance of an operating system including an instance of a low-level, switched fabric input/output (‘I/O’) library, including establishing, in the HFCA by instances of the I/O library in two or more logical partitions and by the hypervisor, separate logical Fibre Channel adapters (‘LFCAs’) for at least two of the logical partitions, each LFCA including an association of an LFCA identifier with at least one range of I/O memory addresses in the address space of a logical partition and transferring, at the behest of application programs in the two or more logical partitions, data between the RAM of the logical partitions and the data storage devices through the LFCAs, the HFCA, and the Fibre Channel fabric.

Abstract: A method, system and computer program product are provided for implementing memory migration of large system memory pages in a computer system. A large page to be migrated from a current location to a target location is converted into a plurality of smaller subpages for a processor or system page table. The migrated page is divided into first, second and third segments, each segment composed of the smaller subpages and each respective segment changes as each individual subpage is migrated. CPU and I/O accesses to respective subpages of the first segment are directed to corresponding subpages of the target page or new page. I/O accesses to respective subpages of the second segment use a dual write mode targeting corresponding subpages of both the current page and the target page. CPU and I/O accesses to the subpages of the third segment access the corresponding subpages of the current page.

Abstract: Data communications through a host Fiber Channel adapter (‘HFCA’) implemented with a computer that includes two or more logical partitions, each logical partition including a separate instance of an operating system, each instance of an operating system including an instance of a low-level, switched fabric input/output (‘I/O’) library, including establishing, in the HFCA by instances of the I/O library in two or more logical partitions and by the hypervisor, separate logical Fiber Channel adapters (‘LFCAs’) for at least two of the logical partitions, each LFCA including an association of an LFCA identifier with at least one range of I/O memory addresses in the address space of a logical partition and transferring, at the behest of application programs in the two or more logical partitions, data between the RAM of the logical partitions and the data storage devices through the LFCAs, the HFCA, and the Fiber Channel fabric.

Abstract: Data communications through a host Fibre Channel adapter (‘HFCA’) implemented with a computer that includes two or more logical partitions, each logical partition including a separate instance of an operating system, each instance of an operating system including an instance of a low-level, switched fabric input/output (‘I/O’) library, including establishing, in the HFCA by instances of the I/O library in two or more logical partitions and by the hypervisor, separate logical Fibre Channel adapters (‘LFCAs’) for at least two of the logical partitions, each LFCA including an association of an LFCA identifier with at least one range of I/O memory addresses in the address space of a logical partition and transferring, at the behest of application programs in the two or more logical partitions, data between the RAM of the logical partitions and the data storage devices through the LFCAs, the HFCA, and the Fibre Channel fabric.

Abstract: Processing multicast messages in a data processing system that includes compute nodes, each of which includes a communications controller, the communications controllers operatively coupled for data communications amongst the compute nodes, each compute node in the data processing system executing at least one logical partition, the data processing system including a hypervisor, where multicast messages are processed by receiving, by more than one of the communications controllers, a multicast message; responsive to receipt of the multicast message, signaling, by one of the communications controllers, an interrupt in the hypervisor without signaling an interrupt by any other communications controller; determining, by the hypervisor, that the message received by the interrupt signaling communications controller is a multicast message; and providing, by the hypervisor, the multicast message to at least one logical partition configured to receive multicast messages.

Abstract: DMA in a computing environment that includes several computers and DMA engines, the computers adapted to one another for data communications by an data communications fabric, each computer executing an application, where DMA includes: pinning, by a first application, a memory region, including providing, to all applications, information describing the memory region; effecting, by a second application in dependence upon the information describing the memory region, DMA transfers related to the memory region, including issuing DMA requests to a particular DMA engine for processing; and unpinning, by the first application, the memory region, including insuring, prior to unpinning, that no additional DMA requests related to the memory region are issued, that all outstanding DMA requests related to the memory region are provided to a DMA engine, and that processing of all outstanding DMA requests related to the memory region and provided to a DMA engine has been completed.

Abstract: Methods, apparatus, and products for broadcasting data in a hybrid computing environment that includes a host computer, a number of accelerators, the host computer and the accelerators adapted to one another for data communications by a system level message passing module, the host computer having local memory shared remotely with the accelerators, the accelerators having local memory for the accelerators shared remotely with the host computer, where broadcasting data according to embodiments of the present invention includes: writing, by the host computer remotely to the shared local memory for the accelerators, the data to be broadcast; reading, by each of the accelerators from the shared local memory for the accelerators, the data; and notifying the host computer, by the accelerators, that the accelerators have read the data.

Abstract: A method, computer program product and computer system for allocating shared address translation tables for memory regions of multiple I/O adaptors, which includes allocating an address translation table to be shared between the memory regions, creating a hardware context for each memory region, and sharing the address translation table across multiple adaptors.

Abstract: Virtualizing a host USB adapter in a virtualized environment maintained by a hypervisor, the hypervisor administering one or more logical partitions, where virtualizing includes receiving, by the hypervisor from a logical partition via a logical USB adapter, a USB Input/Output (‘I/O’) request, the logical USB adapter associated with a USB device coupled to the host USB adapter; placing, by the hypervisor, a work queue element (‘WQE’) in a queue of a queue pair associated with the logical USB adapter; and administering, by an interface device in dependence upon the WQE, USB data communications among the logical partition and the USB device including retrieving, with direct memory access (‘DMA’), USB data originating at the USB device from the host USB adapter into a dedicated memory region for the logical USB adapter.

Abstract: A method, computer program product and computer system for the virtualization of an SAS storage adapter for logical partitions of a computer system, which includes providing a hypervisor, assigning a logical storage adapter to an operating system on one of the logical partitions, configuring the logical storage adapter using the hypervisor, and enabling data storage operations to use the logical storage adapter.

Abstract: DMA in a computing environment that includes several computers and DMA engines, the computers adapted to one another for data communications by an data communications fabric, each computer executing an application, where DMA includes pinning, by a first application, a memory region, including providing, to all applications, information describing the memory region; effecting, by a second application in dependence upon the information describing the memory region, DMA transfers related to the memory region, including issuing DMA requests to a particular DMA engine for processing; and unpinning, by the first application, the memory region, including insuring, prior to unpinning, that no additional DMA requests related to the memory region are issued, that all outstanding DMA requests related to the memory region are provided to a DMA engine, and that processing of all outstanding DMA requests related to the memory region and provided to a DMA engine has been completed.

Abstract: Controlling data flow through a data communications link, the link operating according to a data communications protocol in which a receiver of data communications on the link can suspend data communications on the link for a period of time determined by the receiver, including specifying for the sender a duration for flow control periods; specifying for the sender a number of corrupt communications control packets to be transmitted from the sender to the receiver during a flow control period; determining by the sender whether a flow control message is received from the receiver during a flow control period; altering, in dependence upon whether a flow control message is received from the receiver during a flow control period, the number of corrupt communications control packets; and transmitting, among normal data communications during a subsequent flow control period, the altered number of corrupt communications control packets from the sender to the receiver.

Abstract: Methods, apparatus, and products for broadcasting data in a hybrid computing environment that includes a host computer, a number of accelerators, the host computer and the accelerators adapted to one another for data communications by a system level message passing module, the host computer having local memory shared remotely with the accelerators, the accelerators having local memory for the accelerators shared remotely with the host computer, where broadcasting data according to embodiments of the present invention includes: writing, by the host computer remotely to the shared local memory for the accelerators, the data to be broadcast; reading, by each of the accelerators from the shared local memory for the accelerators, the data; and notifying the host computer, by the accelerators, that the accelerators have read the data.

Abstract: Data processing in a hybrid computing environment that includes a host computer, a plurality of accelerators, the host computer and the accelerators adapted to one another for data communications by a system level message passing module, the host computer having local memory shared remotely with the accelerators, the accelerators having local memory for the plurality of accelerators shared remotely with the host computer, where data processing according to embodiments of the present invention includes performing, by the plurality of accelerators, a local reduction operation with the local shared memory for the accelerators; writing remotely, by one of the plurality of accelerators to the shared memory local to the host computer, a result of the local reduction operation; and reading, by the host computer from shared memory local to the host computer, the result of the local reduction operation.

Abstract: Methods and systems for dynamically acquiring MAC addresses in a virtualized Network environment. A server may be partitioned into a plurality of logical partition. Each logical partition may be associated with a logical adapter to provide network access to the partition. A MAC address may be dynamically allocated to a logical adapter from a predefined range of MAC addresses. Furthermore, the MAC addresses may be unique within a particular subnet, therefore the same MAC address may be assigned to adapters in different subnets.

Abstract: Methods and systems for dynamically acquiring MAC addresses in a virtualized Network environment. A server may be partitioned into a plurality of logical partition. Each logical partition may be associated with a logical adapter to provide network access to the partition. A MAC address may be dynamically allocated to a logical adapter from a predefined range of MAC addresses. Furthermore, the MAC addresses may be unique within a particular subnet, therefore the same MAC address may be assigned to adapters in different subnets.

Abstract: Data communications through a host Fibre Channel adapter (‘HFCA’) implemented with a computer that includes two or more logical partitions, each logical partition including a separate instance of an operating system, each instance of an operating system including an instance of a low-level, switched fabric input/output (‘I/O’) library, including establishing, in the HFCA by instances of the I/O library in two or more logical partitions and by the hypervisor, separate logical Fibre Channel adapters (‘LFCAs’) for at least two of the logical partitions, each LFCA including an association of an LFCA identifier with at least one range of I/O memory addresses in the address space of a logical partition and transferring, at the behest of application programs in the two or more logical partitions, data between the RAM of the logical partitions and the data storage devices through the LFCAs, the HFCA, and the Fibre Channel fabric.

Abstract: Controlling data flow through a data communications link, the link operating according to a data communications protocol in which a receiver of data communications on the link can suspend data communications on the link for a period of time determined by the receiver, including specifying for the sender a duration for flow control periods; specifying for the sender a number of corrupt communications control packets to be transmitted from the sender to the receiver during a flow control period; determining by the sender whether a flow control message is received from the receiver during a flow control period; altering, in dependence upon whether a flow control message is received from the receiver during a flow control period, the number of corrupt communications control packets; and transmitting, among normal data communications during a subsequent flow control period, the altered number of corrupt communications control packets from the sender to the receiver.

Abstract: A method, computer program product and computer system for the virtualization of an SAS storage adapter for logical partitions of a computer system, which includes providing a hypervisor, assigning a logical storage adapter to an operating system on one of the logical partitions, configuring the logical storage adapter using the hypervisor, and enabling data storage operations to use the logical storage adapter.