Pass-through for I/O channel subsystem call instructions for accessing shared resources in a computer system having a plurality of operating systems
First Claim
1. A method of controlling system hardware operations for a plurality of I/O subsystem call instructions issued by any of a plurality of operating systems (OSs), including control programs, executing on a computer electronic complex (CEC) in which the plurality of OSs operate in different logical partitions of resources of the CEC, comprising the steps of:
- executing instructions on a central processor (CPU) of the CEC for any of the OSs, including different types of I/O subsystem call (CHSC) instructions for communicating different types of requests by OSs to the I/O subsystem for requesting different types of I/O subsystem data and operations, including a request for I/O configuration data;
sharing by the OSs of I/O resources of the I/O subsystem;
storing a pass-thru CHSC control mask (CCAM) in system storage having fields associated with different types of CHSC instructions;
accessing the CCAM during CPU execution of any type of CHSC instruction, and accessing a field in the CCAM associated with a type of CHSC instruction being currently executed by the CPU to indicate whether the CPU is to execute the CHSC instruction in a pass-thru mode or not; and
if in pass-thru mode, signalling by the CPU to the I/O subsystem to continue execution of the CHSC instruction by obtaining I/O data and performing operations indicated for the CHSC instruction, including transferring by the I/O subsystem to a storage area available to a requesting OS of requested I/O data associated only with the requesting OS, and filtering out non-meaningful data of the requested type associated with other OSs in the CEC.
2 Assignments
0 Petitions
Accused Products
Abstract
Enables any OS of plural OSs within any of plural logical-resource partitions (LPARs) of a CEC to use interpretive execution for synchronously-executable CHSC (channel subsystem call) commands. A CHSC command authorization mask (CCAM) is provided to control which CHSC commands are allowed to execute interpretively (with pass-through), and which commands are executed with hypervisor intervention (as all prior CHSC commands did). By enabling interpretive execution of those commands which can successfully operate with pass-through, significant system efficiency is obtained. And by disabling interpretive execution for a subset of CHSC commands (which are not allowed to execute with pass-through) potential system failures may be prevented. Thus, interpretive execution may be restricted differently among the OSs in a CEC. Novel CHSC command execution now handles multiple images of shared I/O resources by use of image identifiers, which could not be done before. The information requested by any OS issuing a CHSC command is filtered and optionally compacted by the I/O subsystem responding to the command by only providing information obtained from control blocks associated with the OS which issued the command. This is done by having a set of control blocks for each I/O resource, each control block in the set being associated with a particular OS.
-
Citations
20 Claims
-
1. A method of controlling system hardware operations for a plurality of I/O subsystem call instructions issued by any of a plurality of operating systems (OSs), including control programs, executing on a computer electronic complex (CEC) in which the plurality of OSs operate in different logical partitions of resources of the CEC, comprising the steps of:
-
executing instructions on a central processor (CPU) of the CEC for any of the OSs, including different types of I/O subsystem call (CHSC) instructions for communicating different types of requests by OSs to the I/O subsystem for requesting different types of I/O subsystem data and operations, including a request for I/O configuration data; sharing by the OSs of I/O resources of the I/O subsystem; storing a pass-thru CHSC control mask (CCAM) in system storage having fields associated with different types of CHSC instructions; accessing the CCAM during CPU execution of any type of CHSC instruction, and accessing a field in the CCAM associated with a type of CHSC instruction being currently executed by the CPU to indicate whether the CPU is to execute the CHSC instruction in a pass-thru mode or not; and if in pass-thru mode, signalling by the CPU to the I/O subsystem to continue execution of the CHSC instruction by obtaining I/O data and performing operations indicated for the CHSC instruction, including transferring by the I/O subsystem to a storage area available to a requesting OS of requested I/O data associated only with the requesting OS, and filtering out non-meaningful data of the requested type associated with other OSs in the CEC. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
-
Specification