VM65846: PREPARATION FOR FUTURE MACHINE COMPATIBILITY

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Infrastructure is needed for virtual architecture compatibility
  with possible future machines.
  
  In a single system image (SSI) for live guest relocation
  (LGR) purposes, certain aspects of its virtual architecture
  must be reflected to the guest.  Infrastructure is needed to
  do this in future machines.  Additionally, using this
  infrastructure will lead to less overhead in certain
  circumstances by minimizing the need for interception of
  some instructions when enforcing a guest's virtual
  architecture level.
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of z/VM Single System Image and    *
  *                 Live Guest Relocation                        *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  ****************************************************************
  * RECOMMENDATION: APPLY PTF                                    *
  ****************************************************************
  APAR VM65846 provides infrastructure support in z/VM V6.2, V6.3,
  and V6.4 for any future IBM z Systems server that satisfies the
  statement of direction for the removal of ESA/390 architecture
  support, and must be installed on all the members of an SSI
  cluster before any member will be running on the new server.
  
  There is also a potential performance issue that can occur
  due to the lack of this infrastructure.  This performance
  degradation can occur in a Single System Image (SSI) cluster
  whose members run on more than one machine model type.  The
  symptom is high system overhead on the cluster members running
  on the later model.
  

Problem conclusion

• The code is changed to make Single System Image and Live Guest
  Relocation work properly during migration to a future IBM z
  Systems server.  This code must be applied on all members of an
  SSI cluster prior to IPLing a member on the new server.  This
  code may be installed on one cluster member at a time, as long
  as it is installed on all members before the new server is
  included in the cluster.
  
  This code also minimizes the need to intercept out of SIE to
  enforce the virtual architecture level (VAL) of a guest in a
  relocation domain whose members run on different machine models.
  Before this APAR, those interceptions might occur even when they
  were not absolutely necessary.  This could lead to unnecessary
  system overhead and potential performance issues.  This APAR
  changes the code so that the interceptions are only requested
  when necessary.
  

Temporary fix

• FOR RELEASE VM/ESA CP/ESA R620 :
  PREREQ: VM65867 VM65007 VM65577 VM65306
  CO-REQ: NONE
  IF-REQ: NONE
  FOR RELEASE VM/ESA CP/ESA R630 :
  PREREQ: VM65867 VM65748 VM65586 VM65733
  CO-REQ: NONE
  IF-REQ: NONE
  FOR RELEASE VM/ESA CP/ESA R640 :
  PREREQ: VM65905
  CO-REQ: NONE
  IF-REQ: NONE
  

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UM34945 UM34946 UM34947

Modules/Macros

• HCPARD   HCPARDBK HCPPCCBK HCPPCV   HCPRFI
  

Fix information

• Fixed component name

  VM CP

• Fixed component ID

  568411202

Applicable component levels

• R620 PSY UM34945

     UP16/11/08 I 1000

• R630 PSY UM34946

     UP16/11/08 P 1701

• R640 PSY UM34947

     UP16/11/08 P 1701

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.