# US 10,372,505 B2 · Execution of an instruction for performing a configuration virtual topology change > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,372,505 B2 - Document ID: US10372505B2 - Status: Granted - Kind: B2 - Application number: 16/103,230 - Filed: 2018-08-14 - Published: 2019-01-03 - Granted: 2019-08-06 - Earliest claimed: 2008-01-11 - Assignees: International Business Machines Corporation - Applicants: International Business Machines Corporation - Inventors: Mark S. Farrell; Charles W. Gainey, Jr.; Jeffrey P. Kubala; Donald W. Schmidt - Web page: https://patentgrep.com/patent/US10372505B2 ## CPC - G06F 9/5077: {Logical partitioning of resources; Management or configuration of virtualized resources (specific details on emulation or internal functioning of virtual machines G06F9/455)} - G06F 9/30003: {Arrangements for executing specific machine instructions} - G06F 9/44505: {Configuring for program initiating, e.g. using registry, configuration files} - G06F 15/76: Architectures of general purpose stored program computers (with program plugboard G06F15/08; multicomputers G06F15/16) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract In a logically partitioned host computer system comprising host processors (host CPUs) partitioned into a plurality of guest processors (guest CPUs) of a guest configuration, a perform topology function instruction is executed by a guest processor specifying a topology change of the guest configuration. The topology change preferably changes the polarization of guest CPUs, the polarization being related to the amount of a host CPU resource provided to a guest CPU. ## Claims ### Claim 1 A computer-implemented method comprising: executing, by a processor, a perform topology function instruction to request a configuration change of a topology of a plurality of processors of a configuration, the executing comprising: obtaining, based on the perform topology function instruction, a requested horizontal polarization change of the topology; determining whether the requested horizontal polarization change may be performed; initiating the requested horizontal polarization change, based on determining the requested horizontal polarization change may be performed; rejecting the requested horizontal polarization change, based on determining the requested horizontal polarization change is not to be performed; and setting a condition code, by the processor, to a value indicating whether the requested horizontal polarization change is initiated or rejected. ### Claim 2 (depends on 1) The computer-implemented method according to claim 1, wherein the plurality of processors are guest processors and the configuration is a guest configuration in a logically partitioned computer system. ### Claim 3 (depends on 1) The computer-implemented method according to claim 1, wherein the perform topology function instruction comprises an opcode field and a register field for requesting the change in horizontal polarization. ### Claim 4 (depends on 3) The computer-implemented method according to claim 3, further comprising: obtaining from a function code (FC) field of a register specified by the register field a function code, the function code comprising a horizontal polarization specifier; and based on the function code specifying horizontal polarization, initiating horizontal polarization of processors of the configuration. ### Claim 5 (depends on 4) The computer-implemented method according to claim 4, wherein horizontal polarization comprises providing substantially equal host processor resource to each processor resource. ### Claim 6 (depends on 4) The computer-implemented method according to claim 4, further comprising: based on the requested horizontal polarization change being rejected, setting a reason code (RC) value in a register specified by said register field. ### Claim 7 (depends on 6) The computer-implemented method according to claim 6, wherein, based on the configuration being polarized as specified by the function code prior to execution, the RC value indicates that the configuration is already polarized according to the function code, and wherein, based on the configuration processing an incomplete polarization prior to execution, the RC value indicates that a topology change is already in process. ### Claim 8 (depends on 1) The computer-implemented method according to claim 1, wherein an initiated polarization change is asynchronous to completion of a previously executed perform topology function instruction. ### Claim 9 A computer system comprising: a memory; and a processor in communication with the memory, wherein the computer system is configured to perform a method, said method comprising: executing a perform topology function instruction to request a configuration change of a topology of a plurality of processors of a configuration, the executing comprising: obtaining, based on the perform topology function instruction, a requested horizontal polarization change of the topology; determining whether the requested horizontal polarization change may be performed; initiating the requested horizontal polarization change of processors of the configuration, based on determining the requested horizontal polarization change may be performed; rejecting the requested horizontal polarization change, based on determining the requested horizontal polarization change is not to be performed; and setting a condition code, by the processor, to a value indicating whether the requested horizontal polarization change is initiated or rejected. ### Claim 10 (depends on 9) The computer system according to claim 9, wherein the plurality of processors are guest processors and the configuration is a guest configuration in a logically partitioned computer system. ### Claim 11 (depends on 9) The computer system according to claim 9, wherein the perform topology function instruction comprises an opcode field and a register field for requesting the change in horizontal polarization. ### Claim 12 (depends on 11) The computer system according to claim 11, wherein the method further comprises: obtaining from a function code (FC) field of a register specified by the register field a function code, the function code comprising a horizontal polarization specifier; and based on the function code specifying horizontal polarization, initiating horizontal polarization of processors of the configuration. ### Claim 13 (depends on 12) The computer system according to claim 12, wherein horizontal polarization comprises providing substantially equal host processor resource to each processor resource. ### Claim 14 (depends on 12) The computer system according to claim 12, wherein the method further comprises: based on the requested horizontal polarization change being rejected, setting a reason code (RC) value in a register specified by said register field. ### Claim 15 A computer program product comprising: a computer readable storage medium readable by a processing circuit and storing instructions for performing a method comprising: executing a perform topology function instruction to request a configuration change of a topology of a plurality of processors of a configuration, the executing comprising: obtaining, based on the perform topology function instruction, a requested horizontal polarization change of the topology; determining whether the requested polarization change may be performed; initiating the requested horizontal polarization change, based on determining the requested horizontal polarization change may be performed; rejecting the requested horizontal polarization change, based on determining the requested horizontal polarization change is not to be performed; and setting a condition code, by the processor, to a value indicating whether the requested horizontal polarization change is initiated or rejected. ### Claim 16 (depends on 15) The computer program product according to claim 15, wherein the plurality of processors are guest processors and the configuration is a guest configuration in a logically partitioned computer system. ### Claim 17 (depends on 15) The computer program product according to claim 15, wherein the perform topology function instruction comprises an opcode field and a register field for requesting the change in horizontal polarization. ### Claim 18 (depends on 17) The computer program product according to claim 17, wherein the method further comprises: obtaining from a function code (FC) field of a register specified by the register field a function code, the function code comprising a horizontal polarization specifier; and based on the function code specifying horizontal polarization, initiating horizontal polarization of processors of the configuration. ### Claim 19 (depends on 18) The computer program product according to claim 18, wherein horizontal polarization comprises providing substantially equal host processor resource to each processor resource. ### Claim 20 (depends on 18) The computer program product according to claim 18, wherein the method further comprises: based on the requested horizontal polarization change being rejected, setting a reason code (RC) value in a register specified by said register field.