Browse Prior Art Database

Technique for Testing Instruction Simulation under Start- Interpretive Execution

IP.com Disclosure Number: IPCOM000105119D
Original Publication Date: 1993-Jun-01
Included in the Prior Art Database: 2005-Mar-19
Document File: 2 page(s) / 61K

Publishing Venue

IBM

Related People

Severo, LT: AUTHOR

Abstract

*----------------* | VGUEST | | | |----------------------------* | RGUEST | PR/SM issues SIE instruction to run | (e.g. PR/SM) | Partition |-------------------------------------------------* | Virtual Machine Debugger | | and Instruction Simulator | |----------------------------------------------------------* | Machine | | | *----------------------------------------------------------*

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Technique for Testing Instruction Simulation under Start- Interpretive Execution

*----------------*
|   VGUEST       |
|                |
|----------------------------*
|   RGUEST                   | PR/SM issues SIE instruction to run
|   (e.g. PR/SM)             | Partition
|-------------------------------------------------*
|   Virtual Machine Debugger                      |
|   and Instruction Simulator                     |
|----------------------------------------------------------*
|   Machine                                                |
|                                                          |
*----------------------------------------------------------*

Figure 1.  SIE Testing With PR/SM

      A program is disclosed that allows the testing of of program
code which simulates the execution of machine instructions under
interpretive execution in IBM S/390* architecture, with minimal
overhead.

      In IBM S/390 architecture systems may execute under a
hypervisor, using Start Interpretive Execution (SIE) capability.
When new instructions are added to future machines, it is common to
simulate their execution under a Virtual Machine debugger.  This
simulation code needs to provide the appearance of the existence of
the instruction, both when executed natively on the machine and when
executed under a hypervisor using SIE.  The setup for
 such tests is often complex and consumes a substantial amount of
resources.

      In order to test this simulation code it is commonly necessary
to run a hypervisor operating system under the Virtual Machine
debugger (Fig. 1).  hypervisor (often referred to as "Rguest" in this
context) issues the SIE instruction for a guest operating system
running under it (the Vguest), which in turn is executing the
simulated instructions in a program.  The Virtual Machine debugger
then acts as the hardware and passes results directly to the Vguest.

      The new method eliminates the necessity of an intervening
hypervisor.  The creation of a test program that runs as an Rguest
under the Virtual Machine Debugger that executes the SIE instruction
for a self contained (V=R) Vguest program allows the execution of any...