Last Updated: 30 June 2025

Service and feature packs released for the z/VM 7.4 CP component


z/VM 7.4 introduced linear service to the product. Service fix packs and feature packs are now released on a regular cadence. By installing the latest pack you will receive all service fixes and features for the component. Refer to the change log table below for a comprehensive list of changes to the component since the z/VM 7.4 General Availability date.

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A list of service for z/VM 7.4 CP
Release Level Available Type Crit PE Security HIPER APAR PTF Details
7.4 0201 20250618June 30, 2025 Fix pack No No Yes VM66854 UM90538 z/VM 7.4 CP Fix Pack - Feature 02 Fix 01
  • Error message HCPSWU2832E incorrect for OSH device
  • IQG001 abend when CSCH takes too long
  • Packet and Byte counters for EQDIO incorrect on Q VSWITCH
  • QDIO throughput fields go to 0 in PERFKIT
  • Traffic not flowing across Hipersockets guest LAN
  • HCP3228I sometimes shows 0000 for device address
  • Code was added to take a channel log on VQF002 abends. This log can be used by hardware service personnel to better debug QDIO errors while running under QIOASSIST.
7.4 0200 20250618June 18, 2025 Hardware support No No No VM66824 UM90512 z/VM 7.4 CP Hardware Support - Feature 02 Fix 00
  • IBM z17 Support and Exploitation
    GA1 processor compatibility, EQDIO, and new IBM z17 device support, and ME1 / ML1 VMHCD and VMHCM support for z/VM 7.4 (HCD Requires z/CMS and z/XC support).
     
    Note: RACF users must install RACF 0100 (APAR VM66858) together with this CP z17 Hardware Support APAR. See June 20 z/VM Service Red Alert for more information.
7.4 0102 20250605June 5, 2025 Fix pack Fixed No Yes VM66844 UM90528 z/VM 7.4 CP Fix Pack - Feature 01 Fix 02
PE Corrected with this Fix Pack
  • Transactional Execution Disablement and Use Discovery
    This new function can be exploited to detect applications that use the Transactional Execution Facility.
     
  • A LOGOFF delay may prevent SSI LOGOFF notification
    Code has been changed to ensure that notifications are sent correctly.
     
  • Defects in SCSI alternate device support
    Duplicate alternate device definition checking has been improved to ensure that duplicates are detected and reported correctly.
     
  • FOR command causes CNF001 Soft ABEND
    Command response handling has been corrected to ensure that FOR command responses are delivered as expected.
     
  • PRG004 if invalid buffer length provided to Diagnose 26C
    Hiper related - Code has been changed to validate the Diagnose 26C buffer length.
     
7.4 0101 20250502May 2, 2025 Fix pack Yes No Yes VM66839 UM90524 z/VM 7.4 CP Fix Pack - Feature 01 Fix 01
Update May 6, 2025 - Critical PE introduced with this fix pack.
  • INCORRECT OUTPUT FROM DIAG26C SUBCODE 20
    Diagnose 26c subcode 20 for response formats 0000 0001 thru 0000 0005 can return VSWITCH information structures with an incorrect structure counter. To resolve the problem, the improper return code and possible hanging pointer were addressed.
    May 6, 2025 Update: A critical PE has been found due to this change.
     
  • ACTIVE SERVER ON VSWITCH WITH HIGH RX DISCARD RATE
    Additional conditions are established to determine whether VSWITCH should discard packets waiting to be delivered to a guest.
     
  • UNEXPECTED FORCE ARCH REQUIRED FOR LGR
    The setting of a default architectural value in system initialization was reset to a previous value. This prevents virtual machine relocation from failing due to architecture incompatibility checks.
     
  • VARIOUS ABENDS SYSTEM ITERATOR SERIALIZATION ISSUE
    Hiper related - The iterator was updated to check the HDPBK for table level information instead of checking the first STE in the ST for the table level information. This avoids making the wrong decision if serialization is held on the first STE.
     
  • PRG004 ABENDS
    Hiper related - A missing parameter was added to a subroutine call.
     
7.4 0100 20250403April 3, 2025 Feature pack No No No VM66829 UM90510 z/VM 7.4 CP Feature Pack - Feature 01 Fix 00
  • TRSOURCE IO 5-Digit Device Support
    Extends TRSOURCE support to 5-digit device addresses, which comprise a subchannel-set (SS) number concatenated to the left of the device address. This applies only to real device addresses and therefore to the operand of the TRSOURCE command RDEV keyword. This support has also been added to the DVF component and is available in APAR VM66830.
     
  • Two-Speed Monitoring
    Two-Speed Monitoring provides a mechanism for collecting z/VM Monitor data at two different sampling rates. This avoids disrupting existing client processes that rely on Monitor data collection.
     
7.4 0008 20250325March 14, 2025 Fix pack No No Yes VM66831 UM90506 z/VM 7.4 CP Fix Pack - Feature 00 Fix 08
  • System Hang Due to MDC Consuming Less than 2G Storage
    Logic is added to consumers of MDC frames to examine the ratio of MDC frames <2G to >2G and if skewed <2G then attempt to get a FRMTE conditionally from the >2G available zones. If this request fails, then the old path is used. This ensures a balance of MDC frames and no loop possible.
     
7.4 0007 20250225February 25, 2025 Fix pack No No Yes VM66821 UM90503 z/VM 7.4 CP Fix Pack - Feature 00 Fix 07
  • Unable to Detach CPOWNED Volume Marked Shared
    The logic to dictate whether a device can be detached or not based on CSE sharing still exists, causing unexpected denial of a DETACH command. This fix removes the check and prevents the DETACH denial when a non-SSI system attached device finds itself with spool extents that are not owned by its system.
     
7.4 0006 20250131January 31, 2025 Fix pack No No No VM66819 UM90502 z/VM 7.4 CP Fix Pack - Feature 00 Fix 06
  • Guest Relocation Incompatibility
    Internal handling of the architected value of interest was updated to prevent the relocation errors related to potential architectural incompatibility introduced to the guest.
    March 20, 2025 Update: When fix is applied in an SSI, "FORCE ARCH" is still required for relocations.
     
  • Unplanned Hyperswap on Subchannel Offline Device
    To ensure this incorrect HyperSwap trigger no longer occurs, a set of changes were made to improve the CC3 error recovery path and prevent subchannel offline (SUBCHOFF) devices from persisting in a GDPS environment enabled for HyperSwap auto-quiesce.
     
  • PRG006 Encountered Due to Improper Instruction Input
    Once it was discovered the wrong input was being passed to the failing instruction, the input was fixed. The problem situation was recreated with and without the fix to ensure the abend was avoided.
     
7.4 0005 20241218December 18, 2024 Hot fix Fixed No Yes VM66815 UM90496 z/VM 7.4 CP Hot fix - Feature 00 Fix 05
  • PE Corrected with this Fix Pack
    This fix removes the "System Hang Due to MDC Consuming Less Than 2G Storage" code that was part of fix pack 0004 and restores the previous function.
7.4 0004 20241014October 14, 2024 Fix pack Yes No No VM66800 UM90483 z/VM 7.4 CP Fix Pack - Feature 00 Fix 04
Update Nov. 25, 2024 - PE introduced with this fix pack.
  • System Hang Due to MDC Consuming Less Than 2G Storage
    Logic was added to subroutine HCPPTG:GetFRMTEs that will rebalance the distribution of MDC data frames by looking at the current distribution and preferring frames >2G when the current distribution is skewed toward <2G memory.
    November 19, 2024 Update: A critical PE has been found due to the change in the HCPPTG:GetFRMTEs subroutine. A MCW002 ABEND may occur during normal systems operation (replenishment of the uncleared local available lists) on a system that is paging or near paging.
     
  • RDM024 ABEND After Clearing SSI Slot With Dummy ARD
    The ARD comparison routine was changed to give the correct equality result when two dummy ARDs are compared.
     
  • PEVM66675 Missing Interrupt for Dedicated PCI Function
    PCI function interrupt processing code was modified to not alter adapter interrupt summary bits for dedicated PCI functions. This will prevent missing interrupts for the owning guest.
     
  • ABENDLCK001 HCPLCK+DC8 After NVME EDEV Lost
    An incorrect invocation of the z/VM interrupt handler for NVMe EDEVICES was used when the interruption presented for the PCI Function removal was received. This call to the NVMe interrupt handler has been corrected.
7.4 0003 20240928September 28, 2024 Fix pack No No Yes VM66796 UM90478 z/VM 7.4 CP Fix Pack - Feature 00 Fix 03
  • SXA004 ABEND (ABENDSXA004) caused by the CP CHANGE or CP TRANSFER Commands
    Hiper related - Because the DVMD is only needed for the ESM call, the DVMD is obtained only in the case when that ESM call is needed. To ensure that the conditional obtain and release of the DVMD are in agreement, a test is added to HCPSCO subroutine FINDUSER to call HCPUDRFU instead of HCPUDRGU when the protect flags are on but the TRANSFER or CHANGE came in as a cross-system command.
     
  • CP SPOOL Processing Causes DirMaint Message Flood
    Code has been added to HCPXTPCK to update SPFBRDBT when the SPFBBITS field is updated prior to calling the routines to update the copy systems.
     
  • VARY Hangs After Unplanned Hyperswap
    PPRC/Metro Mirror suspension recovery was updated to reset the associated control unit quiesce condition as soon as possible and then complete the remainder of the associated recovery. This reduces the potential for other processes to be delayed by the pending PPRC suspend recovery process.
7.4 0002 20240920September 20, 2024 Hot fix No Yes No VM66795 UM90474 z/VM 7.4 CP Security APAR - Feature 00 Fix 02
7.4 0001 20240920September 20, 2024 Fix pack No No Yes VM66780 UM90463 Initial fix pack that is provided with the z/VM 7.4 GA installation media.
  • ABEND PRG004 in ISFC Timeout Processing
    ISFC Serialization was expanded to account for the potential interaction between the Link I/O layer and message queue handling which led to the abend.
     
  • MAC Table Synchronization Errors Following VMRELOCATE
    SSI communication used to indicate changes in MAC address usage was updated to ensure the guest LOGOFF case builds a valid request which will update the MAC tables on all members of the SSI.
     
  • ABEND PRG004 in HCPSWL for Multi-VSWITCH LAG Configurations
    The processing of the state change notification received from the OSA adapter was updated to verify the network connection for the port is still operational before attempting recovery. If the port is no longer operational, there is no need to process the state change and it will be discarded.
     
  • XFS File System Errors After HPF I/O to Virtual HyperPAV Alias
    HPF I/O translation was updated to ensure internal control block structures for virtual HyperPAV aliases are updated prior to I/O translation. This ensures the I/O requests are now always translated correctly for the current alias usage.