VM66359: ABENDPRG004 IN HCPLCK+53A FROM HCPIQR

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• VSWITCH response to a stalled OSA Express device may lead to
  PRG004 in HCPLCK+53A when HCPIQR tries to release QIOLOCK.
  
  When the OSA Express fails to process the VSWITCH outbound
  queue (inbound to the OSA card) in a timely fashion, the
  VSWITCH controller declares a "stalled queue" condition and
  resets the OSA interface device to recover.
  
  If VSWITCH logic in HCPIQRRD is processing a queue of packets
  intended for the uplink port, the call to the NIDRECV function
  may trigger the reset (HCPVQATV) which clears an important
  pointer. If this happens while the RD$REDRV flag is set, the
  next cycle cannot access the QIOBK and a residual RD$QIOBK flag
  leads to this attempt to release the QIOLOCK with an invalid
  pointer.
  

Local fix

• Apply PTF
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All customers using a z/VM VSwitch for guest *
  *                 network connectivity.                        *
  *                                                              *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  ****************************************************************
  * RECOMMENDATION: APPLY PTF                                    *
  ****************************************************************
  This is a base problem related to a VSwitch's processing of
  network data transmitted to an OSA UpLink Port, while the port
  transitions from an operational to an inoperable state.  In this
  specific case, the VSwitch Device Driver determines the OSA
  Adapter is no longer processing packets placed on its output
  queue for transmission and therefore terminates the network
  connection to recover.
  
  The ABEND may occur when the VSwitch's incoming data handler
  attempts to recover an OSA Stalled Queue situation.  In this
  case the existing logic appropriately deletes all the pending
  packets waiting for transfer, issues message HCPSWU2832E "OSA
  Express device stall detected."  and proceeds to terminate the
  stalled network connection.  During this process, addressability
  to a key QDIO Control Block is lost.
  
  Unfortunately, there is a very small window where an additional
  packet can be queued by another task after we've terminated the
  network connection, but before we actually perform task
  termination logic.  The new packet will be discovered by task
  termination, forcing the logic to redrive the incoming data
  handler instead of terminating the task.  Since addressability
  to the key QDIO Control Block was lost, it attempts to acquire
  an invalid lock and ABENDs.
  

Problem conclusion

• z/VM's recovery for a Stalled QDIO Queue, appropriately deletes
  all pending packets waiting for transfer, issue message
  HCPSWU2832E "OSA Express device stall detected."  and proceeds
  to terminate the stalled network connection.  During this
  process, addressability to a key QDIO Control Block is lost
  causing HCPIQRRD to ABEND.  Applying this fix will insure all
  key control blocks are preserved when performing OSA Stalled
  Queue Recovery.
  

Temporary fix

• *********
  * HIPER *
  *********
  FOR RELEASE VM/ESA CP/ESA R640 :
  PREREQ: VM66357
  CO-REQ: NONE
  IF-REQ: NONE
  FOR RELEASE VM/ESACP/ESAR710 :
  PREREQ: VM66357
  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:

  UM35612 UM35613

Modules/Macros

• HCPIQR
  

Fix information

• Fixed component name

  VM CP

• Fixed component ID

  568411202

Applicable component levels

• R640 PSY UM35612

     UP20/03/19 I 1000 ¢

• R710 PSY UM35613

     UP20/03/19 P 2101 ¢

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.