Abstract: Mechanisms that address the situation where an input/output (I/O) fabric is shared by more than one logical partition (LPAR) and where each LPAR can share with the other LPARs an I/O adapter (IOA) are provided. In particular, each LPAR is assigned its own separate address space to access a virtual function (VF) assigned to it such that each LPAR's perception is that it has its own independent IOA. Each VF may be shared across multiple LPARs. Facilities are provided for management of the shared resources of the IOA via a Physical Function (PF) of the IOA by assignment of that PF to an I/O Virtualization Management Partition (IMP). The code running in the IMP acts as a virtual intermediary to the VFs for fully managing the VF error handling, VF reset, and configuration operations. The IMP also acts as an interface to the PF for accessing common VF functionality.

Abstract: Mechanisms to address the situation where an input/output (I/O) fabric is shared by more than one logical partition (LPAR) and where each LPAR can share with the other LPARs an I/O adapter (LOA) are provided. In particular, each LPAR is assigned its own separate address space to access a virtual function (VF) assigned to it such that each LPAR's perception is that it has its own independent IOA. Each VF may be shared across multiple LPARs. Facilities are provided for management of the shared resources of the IOA via a Physical Function (PF) of the IOA by assignment of that PF to an I/O Virtualization Management Partition (IMP). The code running in the IMP acts as a virtual intermediary to the VFs for fully managing the VF error handling, VF reset, and configuration operations. The IMP also acts as an interface to the PF for accessing common VF functionality.

Abstract: A method and apparatus in accordance with the present invention provides monitoring a self-adjusting multi-tier processing system. At least one computing resource of one of the tiers of the self-adjusting multi-tier processing system is dynamically bypassed based on at least one predetermined criterion, wherein dynamically bypassing energizes or de-energizes a bypass control switch that operates to route data between tiers of the system in a manner that excludes the at least one computing resource.

Abstract: Mechanisms are provided for an I/O virtualization management partition (IMP) to control the shared functionality of an I/O virtualization (IOV) enabled I/O adapter (IDA) through a physical function (PF) of the IOA while the virtual functions (VFs) are assigned to client partitions for normal I/O operations directly. A hypervisor provides device-independent facilities to the code running in the IMP and client partitions. The IMP may include device specific code without the hypervisor needing to sacrifice its size, robustness, and upgradeability. The hypervisor provides the virtual intermediary functionally for the sharing and control of the IOA's control functions.

Abstract: A “LUN Table” enables Logical Unit Number (LUN) mapping/masking within an Input/Output Virtualization IOV adapter included in a Serial Attached Small Computer System Interface (“SAS” or “Serial Attached SCSI”). A plurality of System Images (“SI”) share block storage through the SAS. The IOV adapter includes one or more Virtual Functions (VF), a Physical Function (PF), and a LUN Table within the PF. The VF allows each SI to communicate I/0 requests with a storage device through the PF. The LUN Table maps the I/0 requests to unique locations within the storage device. Each SI is isolated from all other SIs. Interference between each SI is avoided. A VIOS or a LUN mapping/masking SAN are not required. I/0 latency, processor overhead and storage cost are improved over prior LUN mapping/masking solutions.

Abstract: A method, information processing system, and computer program product manage virtual workspace migration. A set of information associated with a user is analyzed. A future virtual workspace demand associated with the user is predicted based on the analyzing. At least a portion of at least one virtual workspace associated with the user is migrated from a first location to at least a second location based on the future virtual workspace demand that has been predicted.

Abstract: Mechanisms for enabling both native and non-native input/output virtualization (IOV) in a single I/O adapter are provided. The mechanisms allow a system with a large number of logical partitions (LPARs) and system images to use IOV to share a native IOV enabled I/O adapter or endpoint that does not implement the necessary number of virtual functions (VFs) for each LPAR and system image. A number of VFs supported by the I/O adapter, less one, are assigned to LPARs and system images so that they may make use of native IOV using these VFs. The remaining VF is associated with a virtual intermediary (VI) which handles non-native IOV of the I/O adapter. Any remaining LPARs and system images share the I/O adapter using the non-native IOV via the VI. Thus, any number of LPARs and system images may share the same I/O adapter or endpoint.

Abstract: A method of transmitting information to a receiving computer systems includes determining in a processing unit of a computer whether a receiving computer system can receive the information without converting a local format of the information into a canonical format of the information, if it is determined that the receiving computer system cannot receive the information without converting the local format into the canonical format, then converting the local format to the canonical format and transmitting the information to the receiving computer system, and if it is determined that the receiving computer system can receive the information without converting the local format into the canonical format, then transmitting the information to the receiving computer system.

Abstract: The increasing number of Internet users and innovative new services such as e-commerce are placing new demands on Web servers. It is becoming essential for Web servers to provide performance isolation, have fast recovery times, and provide continuous service during overload at least to preferred customers. The invention describes a kernel-based architecture for content-aware service differentiation that protects Web servers against overload by controlling the amount and rate of work entering the system. We have invented a mechanism that provides admission control and service differentiation based on connection and application level information. The application header-based connection control uses application-level information (such as URIs and cookies for HTTP) to define different service differentiation actions. The present invention provides the kernel mechanisms that are more efficient and scalable than application level controls implemented in current Web servers.

Abstract: A method, information processing system, and computer program product manage server placement of virtual machines in an operating environment. A mapping of each virtual machine in a plurality of virtual machines to at least one server in a set of servers is determined. The mapping substantially satisfies a set of primary constraints associated with the set of servers. A plurality of virtual machine clusters is created. Each virtual machine cluster includes a set of virtual machines from the plurality of virtual machines. A server placement of one virtual machine in a cluster is interchangeable with a server placement of another virtual machine in the same cluster while satisfying the set of primary constraints. A server placement of the set of virtual machines within each virtual machine on at least one mapped server is generated for each cluster. The server placement substantially satisfies a set of secondary constraints.

Abstract: Mechanisms for communication between host systems using a socket connection and shared memories are provided. With such socket-based communication, a work queue in the host systems may be used to listen for incoming socket initialization requests. A first host system that wishes to establish a socket communication connection with a second host system may generate a socket initialization request work queue element in its work queue and may inform the second host system that the socket initialization request work queue element is available for processing. The second host system may then accept or deny the request. If the second host system accepts the request, it returns the second half of the socket's parameters for use by the first host system in performing socket based communications between the first and second host systems.

Abstract: Mechanisms for migration of single root stateless virtual functions are provided. A Single-Root PCI Configuration Manager (SR-PCIM) provides a system image (SI) with possible virtual function (VF) migration scenarios supported by the endpoint (EP). The SR-PCIM may be instructed that a stateless migration of a VF and its associated application(s) from one SI to another is required. Outstanding requests to the VF are completed and any applications associated with the VF are removed from the SI and the VF is detached from its associated physical function (PF). The SWI may then attach the VF to a target PF which may be in the same or a different EP. The SWI makes the VF available to the SI with which the VF is now associated and the SI configures the VF thereby making it available for use by associated applications.

Abstract: A computer-implemented method, apparatus, and computer usable program code are disclosed for migrating a virtual adapter from a source physical adapter to a destination physical adapter in a data processing system where multiple host computer systems share multiple adapters and communicate with those adapters through a PCI switched-fabric bus. The virtual adapter is first caused to stop processing transactions. All in-flight transactions that are associated with the virtual adapter are then captured. The configuration information that defines the virtual adapter is moved from the source physical adapter to the destination physical adapter. The in-flight transactions are then restored to their original locations on the destination virtual adapter. The virtual adapter is then restarted on the destination physical adapter such that the virtual adapter begins processing transactions.

Abstract: A method, mechanism and computer usable medium is provided for distributing I/O fabric errors to the appropriate root nodes in a multi-root environment. The case where the I/O fabric is attached to more than one root node and where each root can potentially share with the other roots the I/O adapter (IOA) resources which are attached to the I/O is addressed. Additionally, a method, mechanism and computer usable medium is provided by which errors detected in an I/O fabric may be routed to all root nodes which may be affected by the error, while not being reported to the root nodes that will not be affected by those errors. In particular, distributed computing system which uses the PCI Express protocol to communicate over the I/O fabric is addressed.

Abstract: Mechanisms for differentiating traffic types in a multi-root PCI Express environment are provided. The mechanisms generate a first mapping data structure that, for each single-root virtual hierarchy in the multi-root data processing system, associates a plurality of traffic classes with a plurality of priority groups and maps each traffic class in the plurality of traffic classes to a corresponding virtual channel in a plurality of virtual channels. Moreover, a second mapping data structure is generated that maps each virtual channel in the plurality of virtual channels to corresponding virtual link in a plurality of virtual links of the multi-root data processing system. Traffic of a particular priority group is routed from a single-root virtual hierarchy to a particular virtual link in the plurality of the virtual links based on the first mapping data structure and second mapping data structure.

Abstract: A method and apparatus is provided for routing error messages in a distributed computer system comprising multiple root nodes, and further comprising one or more PCI switches and one or more I/O adapters, wherein each root node includes one or more system images. In one useful embodiment, a method is provided for routing I/O error messages to root nodes respectively associated with the errors contained in the messages. The method includes detecting occurrence of an error at a specified one of the adapters, wherein the error affects one of the system images, and generating an error message at the specified adapter. The method further comprises routing the error message from the specified adapter to the particular root node that includes the affected system image. The error message is then selectively processed at the particular root node, in order to identify the affected system image.

Abstract: A method and apparatus in accordance with the present invention provides monitoring a self-adjusting multi-tier processing system. At least one computing resource of one of the tiers of the self-adjusting multi-tier processing system is dynamically bypassed based on at least one predetermined criterion, wherein dynamically bypassing energizes or de-energizes a bypass control switch that operates to route data between tiers of the system in a manner that excludes the at least one computing resource.

Abstract: A method mechanism is provided for communication between host systems using a transaction protocol and shared memories. Shared memories are initialized based on a discovery process in a communication fabric such that at least one endpoint has address ranges in shared memories of at least two host systems. A transaction oriented protocol may be established for using the shared memories of the host systems to communicate between root complexes and endpoints of the same or different host systems. The transaction oriented protocol specifies a series of transactions to be performed by the various elements, e.g., root complex or endpoint, to push or pull data. Various combinations of push and pull transactions may be utilized.

Abstract: Mechanisms for hot-plug/remove of a new component in a running communication fabric, such as a PCIe fabric, are provided. With these mechanisms, the addition of a new component in the fabric is detected and an event is sent to a multiple root fabric configuration manager. The multiple root fabric configuration manager gathers information about the new component and updates its I/O component tree structure in its configuration data structure to include the new component. The new component may then be utilized via the updated configuration data structure. When a component is to be removed, the multiple root fabric configuration manager receives an event indicating the component to be removed, determines which branches of the tree structure are affected by the removal, and updates its configuration data structure accordingly to remove the component and its associated components from the virtual plane of the removed component.

Abstract: A mechanism is provided for communication between host systems using a queuing system and shared memories. Memory address spaces of the host systems are initialized such that endpoints may be accessible by root complexes across host systems. These memory address spaces may then be used to allow system images, and their corresponding applications, associated with these root complexes to communicate with the endpoints using a queuing system. Such a queuing system may comprise queue structures having doorbell structures for providing information about the queue entries in the queue structures. Queue elements may be generated and added to the queue structures, and the doorbell structure may be written to, in order to thereby inform an endpoint or root complex that queue elements are available for processing. DMA operations may be performed to retrieve the queue elements and the data corresponding to the queue elements.