VM66383: GUEST STUCK IN LOGOFF/FORCE PENDING DUE TO HUNG I/O

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• When hardware errors have occurred and the z/VM EDEVICE driver
  is undergoing recovery, there is a certain window where a guest
  I/O can become stuck behind recovery I/O and never be timed out
  by the driver.  When this occurs, this may cause guest I/O to
  back up, and also impact other guests using the same EDEVICE.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All systems with EDEVs in use.               *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  ****************************************************************
  * RECOMMENDATION: APPLY PTF                                    *
  ****************************************************************
  In systems with EDEVs in use there is a possibilty
  that an interrupt from an EDEV may fail to be reflected
  to the system. When this happens, the virtual machine
  that is using that EDEV may hang waiting on the lost or
  missing interrupt. This change will allow the system to
  detect this situation and clear the condition by reflecting
  an I/O error for the device thereby preventing the hang
  condition.
  

Problem conclusion

• The system Missing Interrupt Handler has been
  altered to always set up missing interrupt detection
  for EDEVs on the system. Because the SCSI container
  has detection code as well the MIH timer has been set
  to a relatively high value (approximately 3 minutes)
  to be a fail-safe for when the container logic fails
  to clear the condition.
  

Temporary fix

Comments

APAR Information

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

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

  UM35659 UM35660

Modules/Macros

• HCPMDT   HCPMIHBK
  

Fix information

• Fixed component name

  VM CP

• Fixed component ID

  568411202

Applicable component levels

• R640 PSY UM35659

     UP20/06/15 I 1000

• R710 PSY UM35660

     UP20/06/15 P 2101 ¢

Fix is available

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