Managing processing associated with selected architectural facilities

• US 9,916,186 B2
• Filed: 11/26/2014
• Issued: 03/13/2018
• Est. Priority Date: 03/18/2014
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Gainey, Jr., Charles W., Gschwind, Michael K.
• Primary Examiner(s): Zhen, Li B
• Assistant Examiner(s): CHEN, SEN THONG
• Application Number:
  US14/554,675
• Publication Number:
  US 20150269004A1
• Time in Patent Office: 1,203 Days
• Field of Search: 718 1
• CPC Class Codes: G06F 11/301 where the computing system is a virtual computing platform, e.g. logically partitioned systems virtual machines G06F9/45533; logical partitioning of resources G06F9/5077
• CPC Class Codes: G06F 11/3409 for performance assessment
• CPC Class Codes: G06F 12/1009 using page tables, e.g. page table structures
• CPC Class Codes: G06F 2009/45583 Memory management, e.g. access or allocation
• CPC Class Codes: G06F 2212/657 Virtual address space management
• CPC Class Codes: G06F 9/30 Arrangements for executing machine instructions, e.g. instruction decode for executing microinstructions G06F9/22
• CPC Class Codes: G06F 9/45533 Hypervisors; Virtual machine monitors
• CPC Class Codes: G06F 9/45558 Hypervisor-specific management and integration aspects
• CPC Class Codes: 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

Abstract

A facility is provided that, when installed, removes from an architecture a selected architectural function, such that the function is not able to be turned on/off regardless of other controls within the environment. When the facility is installed, the architectural function is not supported when processing in an architectural mode based on the architecture. It is as if the selected architectural function is no longer available in the architecture, and in fact, the code implementing the facility may have been deleted, bypassed, or otherwise eliminated. One such architectural function is virtual address translation, such as dynamic address translation (DAT), and the architecture is, for instance, ESA/390.

Claims

1. A method of managing processing with a computing environment, said method comprising:

initiating, by a host processor processing in a first architectural mode, a first guest virtual machine, the first guest virtual machine to process in the first architectural mode, the first architectural mode having a first instruction set architecture and providing a first set of architectural functions;

initiating, by the host processor, a second guest virtual machine, the second guest virtual machine to process in a second architectural mode, wherein the second architectural mode has a second instruction set architecture and provides a second set of architectural functions, the second set of architectural functions being a reduced set of architectural functions provided in the first set of architectural functions, wherein a selected architectural function provided in the first set of architectural functions is absent from the second set of architectural functions, the second architectural mode being a function inhibit mode, and wherein the selected architectural function comprises dynamic address translation; and

performing processing by the second guest virtual machine in the second architectural mode, wherein the performing processing overrides one or more controls associated with the selected architectural function that are defined to control execution of the second guest virtual machine, the overriding enforcing absence the selected architectural function from the second set of architectural functions.

2. The method of claim 1, further comprising:

obtaining by the second guest virtual machine a request to perform an operation, the operation to use or enable the selected architectural function;

based on obtaining the request, determining whether the second guest virtual machine is processing in the second architectural mode; and

based on determining that the second guest virtual machine is processing in the second architectural mode, providing an indication that the selected architectural function is not to be used or enabled.

3. The method of claim 2, wherein the providing the indication includes indicating an error.

4. The method of claim 3, wherein the error is an exception.

5. The method of claim 2, wherein the operation comprises one of a load program status word instruction that attempts to turn on the selected architectural function, a load real address instruction, a set system mask instruction that attempts to turn on the selected architectural function, a store then OR system mask instruction that attempts to turn on the selected architectural function, or an interruption in which an interruption program status word attempts to turn on the selected architectural function.

6. The method of claim 1, wherein the selected architectural function is absent from the second set of architectural functions based on an indicator of the computing environment indicating that the selected architectural function is not supported regardless of whether an enabling/disabling indicator for the selected architectural function indicates enabled.

7. The method of claim 1, wherein the first architectural mode comprises 64-bit addressing and uses 64-bit general purpose registers, and the second architectural mode comprises 31-bit addressing and uses 32-bit general purpose registers.