International Business Machines Corporation

Jonel George

David E Stucki

Allen H Preston

Paul Gregory Greenstein

Steven G Glassen

Moon Ju Kim

John Ted Rodell

Roger E Hough

Matthew A Krygowski

Moon Jung Kim

Charles Franklin Webb

Jeffrey Paul Kubala

Beth A Glendening

James C Daly

Norman Ehsan Shafa

A data processing system has a processing unit and a memory which provides a common pool of physical storage. This storage is initially assigned as either main storage or expanded storage during power on. Subsequent to the initial assignment, storage assigned as main storage or expanded storage may be unassigned and thus returned to the common pool. Once returned to the common pool, the storage may be reassigned as either main storage or expanded storage. The storage reassignment is done dynamically without requiring a reset action and transparent to the operating system and any active application programs.

Main storage and expanded storage reassignment facility

Dynamic Reconfiguration of main storage and expanded storage by means of

A dynamic reconfiguration request for a change in a system's physical configuration is transmitted from a configuration controller to a hypervisor controlling operating systems executing in one or more partitions of the system. The hypervisor translates the physical reconfiguration request into a request for reconfiguration of logical resources known to the operating systems, first verifying it against an installation policy, and passes the requests to the operating systems in the partitions. The operating systems perform logical reconfiguration, then request physical reconfiguration of the hypervisor. The hypervisor initiates the physical reconfiguration through the configuration controller.

System and method for dynamically performing resource reconfiguration in

When the hardware needs to perform a disruptive hardware action, such as a stop of one or more central processors, the hardware provides advance notification to all affected operating systems. The advance notification includes the time that the proposed disruptive action is intended to be initiated and its projected duration. In one instance, the hardware does not proceed with the disruptive action until it receives return acknowledgment from the operating systems that the disruptive action can be performed. The operating systems may respond back to the hardware to proceed as planned with the disruptive action or to reinitiate it only after a specified delay. This allows the operating systems time to prepare for any consequences of the disruptive action.

Method and system for minimizing the effects of disruptive hardware

Enables a host (hypervisor) to access any location in any guest zone in a large memory, when host and guest operands have small addresses that cannot access locations outside of their own zones. System hardware/microcode provides a particular number of windows for host use. Each CPU in the system has one or more window access registers (WARs), and one or more window registers (WRs). The host uses a load WAR instruction to designate each page frame (PF) in the host zone to be used as a host window, and each PF is associated with a respective window number. When the host receives an interception signal requiring the host to access a guest location represented by a guest zone identifier and a guest small address, the host designates one of its window numbers for an access to this guest location. Then, the host executes an activate WR instruction which invokes CPU hardware/microcode that generates a large absolute address for accessing this guest location in the large memory and stores it in a WR associated with the window number. When the host thereafter executes any instruction with an operand small address accessing the host window PF associated with that WR, and CPU hardware/microcode automatically substitutes that guest large address in the WR for the host operand small address for accessing the guest location.

Method of using small addresses to access any guest zone in a large

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Pleasant Valley, NY, United States of America

Jonel George