VIRTUAL MACHINE/EXTENDED ARCHITECTURE MIGRATION AID
o 5664-169

Contents


Announcement Letter Number ZP81-0811 dated October 21, 1981
Europe Middle East Africa - Last Revised on October 21, 1981



Brief Description of Announcement, Charges, and Availability

Customer Letter Section


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*  IBM PROGRAMMING INFORMATION                   OCTOBER 1981   *
*                                                               *
*  IBM PROGRAMMING INFORMATION                                  *
*                                 for Europe, the Middle East   *
*  IBM PROGRAMMING INFORMATION               and Africa.        *
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* This document is provided as general customer information     *
* only. IBM products and services which are announced and       *
* available in your country can be ordered under the applicable *
* standard agreements, terms, conditions and prices in effect   *
* at the time. For further information please contact your      *
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=================================================================
VM/XA MIGRATION AID
o    5664-169
=================================================================
The  VM/XA  Migration  Aid is being provided for the MVS user who
will  be migrating to MVS/XA.  It allows a 3081 user to logically
partition  the  dyadic  processor  between  the  MVS/SP  prefered
virtual  machine  and  the  MVS/XA  virtual  machines.  The VM/XA
Migration  Aid operates on 3081 processors, models D16, D24, D32,
K16,  K24,  and  K32  in  the  Extended  Architecture   mode.  It
supports  concurrently,  one MVS/SP preferred virtual machine and
one  or  more  MVS/XA  virtual  test  machines,  major  test  and
debugging  facilities, and 32 megabyte virtual S/370 machines for
MVS/SP.   VM/System  Product  CMS will be supported only to allow
servicing  of  this product.  The primary objectives of the VM/XA
Migration Aid are:
o   Maximize   performance   for  the  MVS/SP  preferred  virtual
    machine.
o   Support  one  or more MVS/XA test machines with extended test
    facilities.
This  product  will  provide CMS capabilities to support only the
VM/XA  Migration Aid Installation, service, and MVS/XA conversion
requirements.  It  is  not intended to support general CMS users.
No  performance evaluation tools, program products, or networking
capabilities will be available for use on this system.
HIGHLIGHTS
The VM/XA Migration Aid will have the following features:
o   Extended Architecture Support
    -   Large Real Storage
    -   Large Virtual Storage
    -   New Start Interpretive Execution Instruction
    -   New Channel Support
o   MVS/SP Preferred Virtual Machine
    -   Preferred Virtual Machine
    -   Set Address Limit
    -   Master/Dedicated
    -   Dedicated Processor
    -   Dedicated Processor I/O
    -   Preferred Virtual Machine Recovery
o   System Programmer Test Facilities
    -   Virtual Multiprocessing
    -   Debugging Facility
    -   Trace Facility
EXTENDED ARCHITECTURE SUPPORT
The  VM/XA  Migration Aid  will exploit the extended architecture
by  providing support for extended real storage, extended virtual
storage,  hardware  assisted  emulation  for  S/370  and extended
architecture  virtual machines, and the new extended architecture
channels.   For  a  more  detailed  description  on  the extended
architecture, see the appropriate announcement letter.
LARGE  REAL  STORAGE:   The  VM/XA Migration Aid will support all
real  storage configurations allowed by the extended architecture
(extended  architecture  provides  for  offerings  of  real  main
storage up to two gigabytes).
LARGE  VIRTUAL  STORAGE:   Extended  architecture  includes a new
mode  which  allows  the  use  of  31-bit  storage  addresses and
one-megabyte  storage  segments.   Extended  architecture virtual
machines can define storage sizes up to 999 megabytes of storage.
The System/370 Extended Architecture virtual machine can use CCWs
in either S/370 format (format 0) or extended architecture format
(format  1)  for its I/O operations.  Translated channel programs
are always in extended architecture format.
The  VM/XA  Migration  Aid will allow MVS/370 virtual machines to
define storage sizes up to 32 megabytes.
START   INTERPRETIVE   EXECUTION:    A   new  instruction,  Start
Interpretive   Execution,   is   associated   with  the  extended
architecture  emulation facility.  The emulation facility is used
by  the  VM/XA  Migration  Aid  to  provide  hardware support for
several  areas  of  virtual  machine operation, such as: interval
timer, prefixing, address translation, and privileged instruction
handling.
The  VM/XA  Migration  Aid  will dispatch all virtual machines by
executing  the  Start  Interpretive  Execution  instruction.  The
virtual  machine  receives  control  in  emulation  mode and will
continue  to  execute  in  this  mode  until  an  interruption or
interception condition occurs.
The  VM/XA  Migration  Aid  also simulates the Start Interpretive
Execution  instruction  to  allow  the  VM/XA Migration Aid to be
tested and serviced in a virtual machine.
NEW  CHANNEL  SUPPORT:   The VM/XA Migration Aid will support the
new extended architecture channel interface.  At the control unit
interface,  3081  channels  are  similar  to System/370 channels.
However,  at  the programming interface, 3081 channels permit the
offloading  of  some function from the SCP to the channels.  Many
of  the  System/370 channel functions have been replaced with new
ones  that  are  MP  and  performance oriented.  The hardware now
handles the alternate path and I/O queueing management.
The  I/O  supervisor  of  the  VM/XA  Migration  Aid will use new
extended  architecture  I/O  instructions in order to communicate
with  the channels.  In the extended architecture, interrupts are
recognized  by class instead of by channel.  There is no software
association  of devices to control units or channels. Subchannels
are  the addressable units in extended architecture and represent
individual  devices.   The  new  extended  channels  use  new CCW
formats allowing addressing  up to two gigabytes.
MVS/SP PREFERRED VIRTUAL MACHINE
PREFERRED  VIRTUAL MACHINE:  Preferred virtual machine means that
the  preferred virtual machine executes with minimum interpretive
execution.   The  preferred   virtual machine derives performance
benefits  from  a  one to one virtual to real storage addressing.
The  size  of  this  preferred  area  is  specified  in  megabyte
increments  and  physically  begins  at  absolute  zero  of  real
storage.
Note:   Only  MVS/SP  version  1  (release 1 with enhancement and
release 3) is supported as the preferred virtual machine.
SET  ADDRESS  LIMIT:   The  integrity  of  the  preferred virtual
machine  is  enhanced  by  the VM/XA Migration Aid use of the Set
Address   Limit   instruction.    Using  the  Set  Address  Limit
instruction  will  cause  the  System/370  Extended  Architecture
channel hardware to restrict I/O operations for dedicated devices
for  the  preferred  virtual  machine  below  its  boundary,  and
restrict for all other I/O above the boundary.
VIRTUAL  S/370  I/O:   The  VM/XA  Migration  Aid  supports S/370
architecture  virtual  machines,  with  all  S/370 I/O operations
being   automatically   intercepted  out  of  Start  Interpretive
Execution.  The virtual I/O simulation routines will recognize an
S/370  virtual  machine  and convert all of its I/O from S/370 to
System/370  Extended  Architecture  I/O  operations.   The  S/370
virtual   machine   will   have  no  knowledge  of  the  extended
architecture  processor on which it is running as the virtual I/O
simulator  will maintain the S/370 interfaces.  Virtual S/370 I/O
will  be  simulated  as if each virtual device is on a non-shared
S/370 subchannel.

MASTER/DEDICATED  MULTIPROCESSING  SUPPORT:   Master/Dedicated MP
support provides a multiprocessing environment where the 'master'
processor  performs  most  VM/XA  Migration  Aids  of the Control
Program  (CP)  work,  and  then  runs  virtual  machines when all
control  program work is completed.  The 'dedicated' processor is
used to run only the preferred MVS/SP V1 virtual machine.
DEDICATED  PROCESSOR:   With  Dedicated  Processor  support,  the
MVS/SP  preferred  virtual  machine  is  run  in  the 'dedicated'
processor  and all other virtual machines are run in the 'master'
processor.   Dedicated Processor support therefore eliminates all
contention  from  the other virtual machines for that processor's
compute  power.   If the 'dedicated' processor is not used to run
an  MVS/SP  preferred  virtual  machine,  that  processor will be
placed in an enabled wait state.
DEDICATED PROCESSOR I/O:  The preferred virtual machine will have
a  'fast  path  IOS' to handle most S/370 SIOF initiation and I/O
interrupts without having to go to the 'master' processor.
This  is  done  in  a  Master/Dedicated  MP system by devoting an
interrupt  subclass  to  the  dedicated  devices of the preferred
virtual machine.  By running the preferred virtual machine on the
dedicated  CPU enabled only for the dedicated interrupt subclass,
the  operating  system can eliminate the overhead of stacking and
unstacking  I/O  interrupts  for  other  virtual machines and can
avoid CPU switching.
PREFERRED  VIRTUAL  MACHINE  RECOVERY:  This facility attempts to
resume execution of the preferred virtual machine after the VM/XA
Migration  Aid  has  terminated  with  an  abend and initiated an
automatic restart.
SYSTEM PROGRAMMER TEST FACILITIES
VIRTUAL DYADIC:  The Virtual Multiprocessor facility will provide
functional  simulation  of  a  System/370  Extended  Architecture
multiprocessing  computing  system.   The  virtual MP facility is
provided   through  extensions  to  virtual  machine  definition,
dispatching,   and  command  processing.   Console  commands  are
provided  to  create  and  destroy, stop, start and query virtual
processors.
Note:   Virtual  dyadic  will  only  be  supported  for  extended
architecture virtual machines.
VIRTUAL  MACHINE  DEBUGGING:   The  debugging facilities of VM/XA
Migration Aid will provide a significant tool to aid in debugging
a  virtual  machine  or  virtual  MP in the extended architecture
environment.  For example:
o   A  BEGIN  command  starts  execution  of the virtual machines
    processor (or the virtual architecture MP)
    To  look at a virtual machine's storage, the DISPLAY facility
    displays  storage  at  the  user's  terminal,  and  the  DUMP
    facility prints storage to the user's virtual printer.
o   A  STORE  command  can  be  used to alter storage and certain
    architected  areas  of  the  virtual machine (such as general
    registers, control registers, and PSW).
TRACE FACILITY:  The trace function provides the ability to trace
the following events in a virtual machine:
o   Any  activity  against  an  I/O  device or against a range of
    devices.
o   Any  storage  alteration  or  alteration  within  a  range of
    storage.  A value may be specified such that the event traced
    is signaled when that value is set.
o   Any  general  register  alteration  may  be  traced  with  an
    optional value to be set.
o   Selected mnemonics and special instructions can be traced.
VM/XA MIGRATION AID DEVICE SUPPORT LIST
Supported DASD:
2305 MOD 2
3330 MOD 1,11
3333 MOD 1,11
3340
3344
3350 MOD A2,B2,C2
3380 DEDICATED ONLY
3850 DEDICATED ONLY
Supported DASD Control Unit:
2835 MOD 2
3830 MOD 2,3
3851 DEDICATED ONLY
3880 MOD 1
3880 MOD 2,3 DEDICATED ONLY
3880 MOD 11,13 DEDICATED ONLY
Tapes Supported:
3420 MOD 3,4,5,6,7,8
Tape Control Unit Supported:
3803
Printers Supported:
1403 MOD 2,3,5,N1
3211 MOD 1
3800 DEDICATED ONLY
Readers/Punches Supported:
3525 MOD P1,P2,P3
3505 MOD B1,B2
2540 MOD 1
2501 MOD B1,B2
Unit Record Control Unit Supported:
3811
3505
2821
Display Printers Supported:
(Key operator initiated copy only)
3287 MOD 1,1C,2,2C
3286
3284
3288
3289 MOD 1,2
Terminals/Consoles Supported:
3277 MOD 2
3278 MOD 2,3,4
3279 MOD 2A,2B,3A,3B (4 COLOR ONLY)
Terminal Control Unit Supported:
3274 MOD 1B,1D
3274 MOD 21B,21D,31D
3272 MOD 2
Transmission Control Unit Supported:
3704 DEDICATED ONLY
3705 DEDICATED ONLY
Miscellaneous Supported:
CTCA DEDICATED ONLY
ALTERNATE  PATH SUPPORT:  The control required for alternate path
management is provided by the extended architecture channels.
DEDICATED  DEVICES:   Dedicated  devices  can be accessed through
multiple  paths by the System/370-XA virtual machine if there are
multiple  paths  to  the  real  device.   Minidisks and simulated
devices  however  will be accessible only through the first path.
The  Channel  Path Identifiers will be the same for the dedicated
device as for the real device which supports it.
Note:   Support  for  3340  and  3344  alternate  tracks  is only
provided in dedicated mode by the virtual machine.
SPECIFIED OPERATING ENVIRONMENT
PROGRAMMING  REQUIREMENTS:   Assembler  H  Version  2  Release  1
(5668-962)  is  required  for  system  generation  of  the  VM/XA
Migration Aid and for the service of this product.
PROGRAM  INTERFACES:   The  VM/XA Migration Aid will support only
the following systems:
MVS  System  Product  V1 (JES2 or JES3) in a preferred area in UP
mode.
MVS System Product V1 (JES2 or JES3) in a V=V area in UP mode.
MVS/XA in a V=V area in UP and virtual MP mode.
VM/XA Migration Aid in a V=V area in UP and Virtual MP mode.
CMS/370 in a V=V area.
Note:   MVS  System  Product means either MVS/SP 1 enhancement or
release 3 and later releases.
MACHINE REQUIREMENTS:  The VM/XA Migration Aid is designed to run
on the IBM 3081 Processor complex modules D16, D24, D32, K16, K24
and K32 in the extended architecture mode only.
STORAGE  ESTIMATES:  The resident nucleus for the VM/XA Migration
Aid  will  be approximately 1M, and the minimum supported storage
size will be 4M.
PACKAGING:
The  VM/XA  Migration  Aid  will  be  shipped  with  the combined
components of:
 1.  VM/XA Migration Aid Control Program
 2.  VM/System Product CMS
 3.  EREP
COMPATIBILITY STATEMENT:
While  the VM/XA Migration Aid is a Virtual Machine Facility, its
functions will not be equivalent to any of IBM's VM/370 Products.
For example, VM/XA Migration Aid does not support:
 1.  The  following devices (except when used in a dedicated mode
     by an MVS Virtual Machine)
     a.  3380
     b.  3800
     c.  3850
     d.  3705
 2.  Networking facilities
 3.  Program Products
 4.  Remote terminals
 5.  Monitoring facilities
 6.  CMS use other than for installation and service of the VM/XA
     Migration Aid, and migration from MVS/SP to MVS/XA.
The  VM/XA  Migration  Aid user is a MVS customer who is ready to
migrate  to MVS/XA and would like to continue MVS/SP non critical
work while testing MVS/XA and associated subsystems.  MVS/SP will
be  run  as the preferred virtual machine on one processor of the
complex,  and  cannot be run in virtual MP mode.  The MVS/XA test
virtual machines and CMS activity will run on the other processor
of the complex.
PUBLICATIONS:
o   VM/XA  Migration  Aid General Information Manual (GC19-6213),
    will be available June, 1982.
Additional    publications   will   be   available   at   general

availability.
PROGRAM SERVICES:
Central  Service,  including  the  IBM  Support  Center,  will be
available  until  discontinued  by  IBM  upon  twelve (12) months
written notice.
Local   Licensed   Program   Support   will  be  available  until
discontinued  by  IBM  upon  twelve  (12)  months written notice.
Local  Licensed  Program Support will be provided under the terms
and  conditions  of  the  Agreement  for  Local  Licensed Program
Support for IBM Licensed Programs at the Monthly Licensed Program
Support  Charge,  Monthly  Additional  Licensed  Program  Support
Charge, or will be provided at the applicable hourly rate.  Local
Licensed  Program  Support  will  be  provided  by  IBM  Customer
Engineering.
TESTING PERIOD: 60 days.
WARRANTED:   Yes,  in  accordance  with  the  Agreement  for  IBM
Licensed Programs.
INSTALLATION   LICENSE  APPLIES:   No.   A  separate  license  is
required  for  each  designated  machine  on  which  the licensed
program  materials  will  be used except as otherwise provided by
IBM.
CHARGES:
Initial License Charges: ................... )
Monthly Charges: ........................... ) Consult your
Monthly Licensed Program Support Charge: ... ) IBM
Monthly Additional Licensed Program          ) Marketing
  Support Charge: .......................... ) Representative
PLANNED AVAILABILITY:  By January 1984.