Abstract: A computer-implemented method for transferring a reserve to a target host, according to one embodiment, includes granting to a source system, by a control unit, a reserve for a volume of a storage device. A push reserve command is received from the source system. The push reserve command specifies: a transfer of the reserve to a target system, parameter data identifying the target system, and path information specifying the source system. The reserve is transferred only to the target system in response to release of the reserve by the source system.

Abstract: According to one embodiment, a host system includes logic adapted for receiving device information from a source system, logic adapted for building a virtual device based at least in part on the received device information, logic adapted for transferring a reserve of a storage device to the host system and/or receiving results of transferring the reserve to the host system, logic adapted for determining if the reserve is held by the host system, logic adapted for recording the reserve if the reserve is held by the host system, and logic adapted for sending a notification that the reserve is not held by the host system if the reserve is not held by the host system. Other systems and computer program products are also described according to various embodiments.

Abstract: A computer-implemented method for transferring a reserve to a target host, according to one embodiment, includes granting to a source system, by a control unit, a reserve for a volume of a storage device. A push reserve command is received from the source system. The push reserve command specifies: a transfer of the reserve to a target system, parameter data identifying the target system, and path information specifying the source system. The reserve is transferred only to the target system in response to release of the reserve by the source system.

Abstract: According to one embodiment, a method includes receiving device information from a source system; building a virtual device on a host system based at least in part on the received device information; at least one of: transferring a reserve of a device stored on a storage device to a target system; and receiving results of transferring the reserve to the target system; determining if the reserve is held by the target system; recording the reserve if the reserve is held by the target system; and sending a notification that the reserve is not held by the target system if the reserve is not held by the target system. Other methods are also described according to various embodiments.

Abstract: In an exemplary embodiment of this disclosure, a system may include a first hypervisor, a second hypervisor, and a shared memory set. The first hypervisor and the second hypervisor run over a single logical partition. The shared memory set is accessible by both the first hypervisor and the second hypervisor, and the first hypervisor is configured to communicate with the second hypervisor by writing to the shared memory. The second hypervisor may provide support for hardware that is not supported by the first hypervisor, which hardware may be accessed by the first hypervisor through communications facilitated by use of the shared memory.

Abstract: Embodiments relate to a method for encapsulating a virtual server in a hypervisor subpartition of a single logical partition to provide additional hardware support and advanced virtualization functions. An aspect includes running a first hypervisor and one or more additional hypervisors over a single logical partition. A request to manage a virtual server is received at the first hypervisor. The request is then analyzed to determine what resources are necessary to manage the virtual server. Based on the analyzed request, one of the first hypervisor or the one or more additional hypervisors is selected to complete the request.

Abstract: Embodiments relate to a method for encapsulating a virtual server in a hypervisor subpartition of a single logical partition to provide additional hardware support and advanced virtualization functions. An aspect includes running a first hypervisor and one or more additional hypervisors over a single logical partition. A request to manage a virtual server is received at the first hypervisor. The request is then analyzed to determine what resources are necessary to manage the virtual server. Based on the analyzed request, one of the first hypervisor or the one or more additional hypervisors is selected to complete the request.

Abstract: Embodiments relate to a method for encapsulating a virtual server in a hypervisor subpartition of a single logical partition to provide additional hardware support and advanced virtualization functions. An aspect includes running a first hypervisor and one or more additional hypervisors over a single logical partition. A request to manage a virtual server is received at the first hypervisor. The request is then analyzed to determine what resources are necessary to manage the virtual server. Based on the analyzed request, one of the first hypervisor or the one or more additional hypervisors is selected to complete the request.

Abstract: In an exemplary embodiment of this disclosure, a system may include a first hypervisor, a second hypervisor, and a shared memory set. The first hypervisor and the second hypervisor run over a single logical partition. The shared memory set is accessible by both the first hypervisor and the second hypervisor, and the first hypervisor is configured to communicate with the second hypervisor by writing to the shared memory. The second hypervisor may provide support for hardware that is not supported by the first hypervisor, which hardware may be accessed by the first hypervisor through communications facilitated by use of the shared memory.

Abstract: Embodiments relate to a method for encapsulating a virtual server in a hypervisor subpartition of a single logical partition to provide additional hardware support and advanced virtualization functions. An aspect includes running a first hypervisor and one or more additional hypervisors over a single logical partition. A request to manage a virtual server is received at the first hypervisor. The request is then analyzed to determine what resources are necessary to manage the virtual server. Based on the analyzed request, one of the first hypervisor or the one or more additional hypervisors is selected to complete the request.

Abstract: According to one embodiment, a method includes receiving device information from a source system; building a virtual device on a host system based at least in part on the received device information; at least one of: transferring a reserve of a device stored on a storage device to a target system; and receiving results of transferring the reserve to the target system; determining if the reserve is held by the target system; recording the reserve if the reserve is held by the target system; and sending a notification that the reserve is not held by the target system if the reserve is not held by the target system. Other methods are also described according to various embodiments.

Abstract: According to one embodiment, a host system includes logic adapted for receiving device information from a source system, logic adapted for building a virtual device based at least in part on the received device information, logic adapted for transferring a reserve of a storage device to the host system and/or receiving results of transferring the reserve to the host system, logic adapted for determining if the reserve is held by the host system, logic adapted for recording the reserve if the reserve is held by the host system, and logic adapted for sending a notification that the reserve is not held by the host system if the reserve is not held by the host system. Other methods, systems, and computer program products are also described according to various embodiments.

Abstract: A measurement facility is provided for capturing and presenting fine-grained usage information for adapter functions in an input/output subsystem. Adapter specific input/output traffic is tracked on a per function basis and the results are dynamically presented to the user. This information is useful for performance tuning, load balancing and usage based charging, as examples.

Abstract: A method for changing self-description data of a functional device in a computing system. The method may include virtualizing the functional device to create a virtual functional device, and adding, changing, or removing information in the self-description information sent from a functional device as a part of virtualization of the device by a hypervisor. Changing the self-description data of the functional device occurs after the self-description data has left the functional device.

Abstract: A method, system, program product and computer data structure for providing for two levels of server virtualization. A first hypervisor enables multiple logical partitions to share a set of resources and provides a first level of virtualization. A second hypervisor enables multiple, independent virtual machines to share the resources that are assigned to a single logical partition and provides a second level of virtualization. All events for all of the virtual machines within said single logical partition are grouped into a single partition-owned event queue for receiving event notifications from the shared resources for that single logical partition. A request for an interrupt is signaled for the grouped events from the partition-owned event queue for the demultiplexing of grouped events, by the machine, from the partition-owned event queue into individual, virtualized event queues that are allocated on a per virtual machine basis.

Abstract: A method, system, program product and computer data structure for providing for two levels of server virtualization. A first hypervisor enables multiple logical partitions to share a set of resources and provides a first level of virtualization. A second hypervisor enables multiple, independent virtual machines to share the resources that are assigned to a single logical partition and provides a second level of virtualization. All events for all of the virtual machines within said single logical partition are grouped into a single partition-owned event queue for receiving event notifications from the shared resources for that single logical partition. A request for an interrupt is signaled for the grouped events from the partition-owned event queue for the demultiplexing of grouped events, by the machine, from the partition-owned event queue into individual, virtualized event queues that are allocated on a per virtual machine basis.