VIRTUAL MACHINE/EXTENDED ARCHITECTURE (VM/XA) SYSTEMS FACILITY
Contents


Announcement Letter Number 285-044 dated February 12, 1985
US - Last Revised on February 12, 1985



Brief Description of Announcement, Charges, and Availability

     The VM/XA Systems Facility is a strategic new VM product for the
XA environment that supersedes the VM/XA Migration Aid. It
incorporates all existing VM/XA Migration Aid functions, offers
additional capabilities, and provides new processor and device
support.  Additionally, the VM/XA Systems Facility offers significant
performance benefits through exploitation of the XA Start
Interpretive Execution (SIE) assist.
       The VM/XA Systems Facility dramatically extends the range of
Multiple Virtual Storage/Extended Architecture (MVS/XA) environments
supported by VM, with emphasis on guest production, migration, test
and maintenance.  The VM/XA Systems Facility delivers new virtual
machine capability that yields increased flexibility for guest
systems.


Customer Letter Section

HIGHLIGHTS
       The VM/XA Systems Facility  licensed program incorporates all
the functions of VM/XA Migration Aid Release 2 and offers additional
function and device support.
       New processor and device support in VM/XA Systems Facility
include:
o   Support of the IBM 3090 Processor complex
o   Support of the Start Interpretive Execution (SIE) assist for the
    IBM 308X and 3090 Processors
o   Dedicated-only support of IBM 3090 expanded storage
o   Full support of the IBM 3800-1 Printer
o   Dedicated support of the IBM 3880-23 DASD Control Unit
o   Dedicated support of the IBM 3380-AE4, BE4 DASD
o   Dedicated support of the IBM 3370 DASD
o   Dedicated support of the IBM 3430 Tape
       Significant functions of VM/XA Systems Facility include:
o   Full dyadic* utilization for V=R dyadic* guests
o   Concurrent virtual and real Reserve/Release Support for shared
    DASD
o   A priority scheduler
o   Improved availability via the incorporation of a Missing
    Interrupt Handler
o   Spooling enhancements including a spool-to-tape program
o   A subset of the VM/SP Inter-User Communication Facility (IUCV)
o   Support for Named Saved Systems
o   Additional command compatibility with VM/SP(370)
o   Support of SMSG and MSGNOH commands
o   Dump Viewing Facility Enhancements
o   CMS 3.1 for installation and maintenance
* In describing software facilities, the term 'dyadic' applies to
  both dyadic processors and the IBM 4381-3 dual processor.
DESCRIPTION
       The VM/XA Systems Facility provides new capability allowing
users to run multiple IBM System/370 and IBM System/370 Extended
Architecture operating systems in a uniprocessor or dyadic processor.
The VM/XA Systems Facility has value in a wide variety of customer
installations including:
o   Test and Maintenance
           The VM/XA Systems Facility provides a comprehensive and
    flexible environment for maintaining IBM System/370 and IBM
    System/370 Extended Architecture systems. The multiple virtual
    machine capability of the VM/XA Systems Facility allows the
    creation and testing of a wide variety of simulated environments
    including loosely coupled multiprocessor guest configurations.
    Aided by extensive debugging and trace facilities, the VM/XA
    Systems Facility can provide significant improvements in system
    programmer productivity and resource utilization.
o   Guest Production and Migration
           For the migrating customer, the VM/XA Systems Facility
    allows continued production (normally as a V=R preferred guest)
    for the current operating system (MVS, VSE, VS1) and concurrent
    installation and test of MVS/XA.  The VM/XA Systems Facility
    reserve/release support enhances the migration and production
    environments by allowing the V=R production guest to share DASD
    with other test guests and other real processors.  By allowing
    both production and MVS/XA installation during normal working
    hours, overall efficiency and productivity may be increased.
           The improved V=R guest performance provided by the 370-XA
    SIE Assist, coupled with the ability of a V=R guest to fully
    utilize a dyadic processor, make the VM/XA Systems Facility
    effective for guest production.
           Full CMS support can be obtained by running VM/SP or VM/SP
    HPO as a V=R or V=V guest of the VM/XA Systems Facility. The new
    scheduler facilities provide the capability to favor particular
    V=R or V=V guests.  This facility can be used to tune the Systems
    Facility, as required, to potentially improve the responsiveness
    of CMS users running under a VM/SP or VM/SP HPO virtual machine.
    The CMS component of the VM/XA Systems Facility is supported only
    for installation and maintenance.
The diagrams attached to this announcement depict typical processor
configurations and show the enhancements made to dyadic support.
(SEE HARD COPY FOR ATTACHMENTS.)
SUPPORT OF THE IBM 3090 PROCESSOR COMPLEX
       The VM/XA Systems Facility will provide support for the IBM
3090 Processor including 48-channel support and the expanded storage
facility (dedicated only).  IBM System/370 mode guests may now define
and use up to 32 channels.  Guests that also support the expanded
storage facility can use this facility as a dedicated-only resource
under the VM/XA Systems Facility.
FULL DYADIC UTILIZATION
       The VM/XA Systems Facility will exploit the full dyadic
capabilities of the IBM 4381-3 (dual processor), IBM 3081, IBM 3090
Model 200 and the IBM 3084 and IBM 3090 Model 400 (in partitioned
mode). Specifically, support is provided to allow V=R guests that
support dyadics, such as MVS/XA or VM/SP HPO, to simultaneously run
on both instruction  processors  in full dyadic mode.  This
enhancement, combined with the scheduler facilities in the VM/XA
Systems Facility, allows a production dyadic V=R guest to utilize all
of the available CPU resources.  Additionally, V=V guests may be run
on both CPUs of the dyadic when there is no dedicated V=R guest. This
enhancement allows for better balancing of workloads between the two
processors and for better dyadic utilization.
SUPPORT OF THE START INTERPRETIVE EXECUTION (SIE) ASSIST
       This enhancement is provided to improve the performance of V=R
preferred guests.  In a laboratory test environment on an IBM 3081
running as a preferred guest, MVS/XA achieved an internal throughput
rate of 90-92% relative to the native rates on the same processor.
MVS/370 running as a preferred guest achieved an internal throughput
rate of 86-88% when tested in this same environment. This represents
an internal throughput rate improvement of up to 14% over that
attainable on the VM/XA Migration Aid for the same workload. This
improvement is due to a reduction in the number of instructions VM/XA
System Facility is required to execute in support of I/O instructions
for dedicated devices attached to either System/370 or System/370-XA
preferred guests. Most I/O instructions and associated interrupts are
normally handled entirely by the processor in interpretive execution
mode.
       Detailed performance information will be provided in the
fourth quarter of 1985.
INCORPORATION OF A PRIORITY SCHEDULER FOR GUESTS
       The new scheduler will allocate processor time based on a
user's given "share" of processor power.  This facility affords
several production management benefits.  Coupled with other paging
related commands, the user can now allocate system resources (storage
and CPU) to potentially allow for multiple production environments,
or potentially improve CMS responsiveness by favoring a VM/SP or
VM/SP HPO virtual machine.  Since these commands can be entered at
any time, the user can dynamically tune the VM/XA Systems Facility to
best support changing requirements.
RESERVE/RELEASE SUPPORT
       The VM/XA Systems Facility now allows guest operating systems
to issue Reserve/Release commands to DASD devices such that they may
be concurrently shared among both virtual machines and other
processors during migration and production.
FULL SUPPORT OF THE IBM 3800-1 PRINTER
       The IBM 3800-1 Printer is supported as both a real and a
virtual device, including full error recovery and image library
support. This support allows the 3800 printer to be used by the
Systems Facility as a spooling device. Additionally, guest operating
systems may define the 3800 as a virtual printer in order to utilize
the special printing facilities of the 3800.
DEDICATED-ONLY SUPPORT OF THE IBM 3880-23 DASD CONTROL UNIT
       VM/XA Systems Facility  will provide dedicated only support
for the 3880-23 Control Unit and attached devices.
DEDICATED-ONLY SUPPORT OF THE IBM 3380 MODELS AE4 AND BE4
       The recently announced 3380 Models AE4 and BE4 DASD can be
used as dedicated-only devices.
DEDICATED-ONLY SUPPORT OF THE IBM 3370
       The 3370 DASD can be used as dedicated-only devices by VS1,
VSE, VM/SP, and VM/SP HPO.
DEDICATED-ONLY SUPPORT OF THE IBM 3430 TAPE

       The 3430 tape support for VM/XA Systems Facility will allow
the device to be attached to a user's virtual machine as a
dedicated-only device.
NAMED SAVED SYSTEMS
       This support allows a user to IPL a virtual machine and when
the IPL is complete, the virtual machine status can be saved and
given a name via the SAVESYS command. Subsequently, this saved system
can be invoked simply by entering an IPL command specifying the name
used in the SAVESYS command.  This facility can  reduce guest IPL
times which can be beneficial to productivity during installation,
maintenance, and testing of guest operating systems.
ADDITIONAL COMMAND COMPATIBILITY WITH VM/SP
       Changes will be made to the external characteristics of VM/XA
Systems Facility  that make it more compatible with the externals of
VM/SP Release 3 and the corresponding VM/SP HPO release with respect
to commands and command responses.
SUPPORT OF SMSG AND MSGNOH COMMANDS
       These facilities allow the system operator to send messages to
other virtual machines and is commonly used to query and control
service machines such as RSCS and PVM.
ADDITIONAL RAS VIA THE INCORPORATION OF A MISSING INTERRUPT HANDLER
       The Missing Interrupt Handler enhances the availability of
virtual machines by detecting missing interrupts of supported
devices. Once detected these conditions are corrected or passed to
the guest operating system. This facility can minimize deadlocks and
system hangs.  Commands are provided to set timing parameters, turn
the function on and off and to display status.
SPOOLING ENHANCEMENTS
       There are three new functions provided by the spooling
enhancements.
o   The spool-to-tape function allows spool files and system data
    files to be saved on tape.  This function may be used to migrate
    spool files between VM/SP Release 3.0 and VM/XA Systems Facility.
o   Printer Separators have been made compatible, although not
    identical, with those in VM/SP.
o   Forms support, allowing spool files to be manipulated based on
    the form name or form number, has been made compatible with the
    existing support in VM/SP.
INCORPORATION OF A SUBSET OF THE VM/SP IUCV FACILITY
       The Inter-User Communications Vehicle (IUCV) is a
communications facility that enables a virtual machine to communicate
with other virtual machines and can be used to enhance testing
capabilities by allowing test cases and data to be passed between
machines.
DUMP VIEWING FACILITY ENHANCEMENTS
       The following enhancements are provided:
o   A HELP facility has been added to assist the user with dump
    viewing facility commands and subcommands.
o   TRACE scrolling allows a user to scroll forward and backward
    through the TRACE entries.
o   Formatted TRACE print formats the printed TRACE entries in the
    same format as the displayed TRACE entries under DUMPSCAN.
CMS 3.1 FOR INSTALLATION AND MAINTENANCE
       CMS 3.1 is provided for installation and maintenance and
allows system programmers to use the System Product Interpreter.
SCHEDULE
       Planned availability is November 1985.
TECHNICAL INFORMATION
SPECIFIED OPERATING ENVIRONMENT
HARDWARE REQUIREMENTS: The VM/XA Systems Facility is supported on all
models of the following processors operating in System/370-XA mode:
o   IBM 4381 Model Group 1 (Requires System EC #993078)
o   IBM 4381 Model Group 2 (Requires System EC #866904)
o   IBM 4381 Model Group 3 (Requires System EC #329507)
o   IBM 3081
o   IBM 3083
o   IBM 3084 (in partitioned mode)
o   IBM 3090 Model 200
o   IBM 3090 Model 400 (in partitioned mode)
SOFTWARE REQUIREMENTS: Assembler H Version 2 is required to:
o   Generate extended architecture instruction streams
o   Generate VM/XA Systems Facility
o   Service VM/XA Systems Facility
       The current version of EREP must be ordered and installed.
       The VM/XA Systems Facility  is designed to support the
following operating systems as virtual machines, either in a V=V or a
V=R preferred area:
o   MVS/SP Version 1 Release 1 with Release 1 enhancement
o   MVS/SP Version 1 Release 3 and later (MVS/370)
o   MVS/SP Version 2 Release 1 and later (MVS/XA)
o   VM/SP Release 2.1 and later
o   VM/SP HPO Release 3.0 and later
o   OS/VS1 Release 7 with BPE Release 3 and later
o   VSE/Advanced Function Release 3 with service level 8205 and later
o   VM/XA System Facility (V=V only)
o   VM/XA Migration Aid Release 1 and later (V=V only)
       The following licensed programs are supported by the VM/XA
Systems Facility:
o   Assembler H Version 2 (5668-962)
o   VM/XA Migration Aid Remote 3270 Display Option (5664-183)
o   RSCS Networking Version 1 Release 3 (5748-XP1)
o   VM/Pass-through Facility Release 2 (5748-RC1)
COMPATIBILITY: The VM/XA Systems Facility  is upwardly compatible
from Release 2 of the VM/XA Migration Aid, with the following
exceptions:
o   Release 2 spool files cannot be processed by VM/XA Systems
    Facility.  Refer to the VM/XA Systems Facility Installation
    Manual (which will be available at general availability) for
    migration requirements and procedures.
o   Some commands have been changed in order to make them more
    compatible with VM/SP and VM/SP HPO. Consult the VM/XA Systems
    Facility CP Command and Diagnose Code Reference for details.
STORAGE ESTIMATES: The resident nucleus for the VM/XA Systems
Facility will be approximately one megabyte, and the minimum
supported storage size will be four megabytes.
PACKAGING: The VM/XA Systems Facility will be shipped with the
combined components of:
o   VM/XA Systems Facility control program (CP)
o   VM/XA Systems Facility CMS at the VM/SP Release 3.1 level (for
    installation and service of VM/XA Systems Facility and for the
    operation of licensed programs supported by VM/XA Systems
    Facility)
o   Dump viewing facility
RELIABILITY, AVAILABILITY, AND SERVICEABILITY (RAS)
       In addition to the several RAS facilities provided by virtual
machines, such as individual machine error isolation and extensive
debugging services, the VM/XA Systems Facility offers significant
availability features for preferred guests and for central storage
machine-check recovery.
       The VM/XA Systems Facility preferred guest recovery capability
allows preferred guest machines to resume operation without a re-IPL
after certain control program and hardware failures. This can improve
the availability of production environments.
       The missing interrupt handler in VM/XA Systems Facility is
used to detect and correct or pass missing I/O interrupt conditions
to guest machines.
       The VM/XA Systems Facility supports and utilizes the
double-bit central storage error detection capabilities of IBM
processors. When a double-bit central storage error is detected, if
not corrected by the hardware, the VM/XA Systems Facility will
perform frame deallocation for pageable storage frames. At next
reference, a new frame will be allocated for the deallocated frame.
For preferred guests running V=R, this error condition is detected
and passed to the guest for handling by the guest SCP. This
capability can minimize abnormal termination of guest SCP on certain
central storage failures.
SECURITY, AUDITABILITY, AND CONTROL
       The VM/XA Systems Facility includes several facilities to
ensure the security and integrity of the system. Each guest and CMS
user runs in a unique virtual machine definition which, in
combination with IBM 370-XA features, prohibits one user from
accessing another's data in storage (unless specifically allowed
through shared segments). Additionally, the VM/XA Systems Facility
and IBM 370-XA channel facilities provide protection against channel
programs accessing another user's virtual addresses. Minidisk
security is provided by a password facility to control both read-only
and read-write access.  Both LOGON ID and PASSWORD checking are
provided to minimize unauthorized system access. User management is

responsible for the selection, application, adequacy, and
implementation of these features and for the appropriate application
and administrative controls.
ORDERING INFORMATION
Ordering information will be provided at availability.
CHARGES, TERMS, AND CONDITIONS
CHARGES
       The initial license charge is due and the monthly charge
commences for each basic license upon completion of the applicable
testing period. The initial license charge is due and the monthly
charge commences for each DSLO license on the effective date of
additional licenses.
INITIAL LICENSE CHARGE:
Basic License             $10,500
DSLO                        7,875
MONTHLY CHARGE:
Basic License              $3,500
DSLO                        2,625
       Note: At availability of VM/XA Systems Facility, current
licensees of the VM/XA Migration Aid will not be charged an
additional initial license charge when ordering the VM/XA Systems
Facility to replace the VM/XA Migration Aid.
TERMS AND CONDITIONS
WARRANTED:
Basic License - Yes, in accordance with the Agreement for IBM
Licensed Programs.
DSLO - Not applicable.
LICENSED PROGRAM MATERIALS AVAILABILITY: Restricted Materials - Yes.
This licensed program will be available with some licensed program
materials designated as RESTRICTED MATERIALS OF IBM.  In addition,
some modules will be available without source licensed program
materials. These modules will be available in object code.
TESTING PERIOD:
Basic License - Two months
DSLO - Not applicable
PROGRAM SERVICES: Central service, including the IBM support center,
for the basic license will be available until discontinued by IBM
upon 12 months' written notice. For DSLO licenses, central service,
including the IBM support center, will be provided only through the
customer location designated for the basic license.
       Local licensed program support will be available under the
terms and conditions of the Agreement for Local Licensed Program
Support for IBM Licensed Programs at the monthly licensed program
support charge, or the monthly multiple licensed program support
charge, or will be provided at the applicable IBM hourly service
rate.  Local licensed program support will be provided by the IBM
National Service Division.
PROGRAM CURRENCY: Program services, previously announced for the
VM/XA Migration Aid Release 2, will be available for 12 months after
the availability of this release of VM/XA Systems Facility.
MONTHLY LICENSED PROGRAM SUPPORT CHARGE: $583
MONTHLY MULTIPLE LICENSED PROGRAM SUPPORT CHARGE: $933
INSTALLATION LICENSE OR LOCATION LICENSE APPLIES: No. A separate
license is required for each machine on which the licensed program
materials will be used, except as otherwise provided by IBM.