Summary of Changes for z/VM: Performance

This information includes terminology, maintenance, and editorial changes. Technical changes or additions to the text and illustrations for the current edition are indicated by vertical lines and angle brackets (|<  >|) surrounding the change.

SC24-6301-73, z/VM 7.3 (September 2025)

This edition includes changes to support product changes that are provided or announced after the general availability of z/VM® 7.3.

[7.3 VM66878] Enhanced QDIO virtual switch vNIC simulation

With the PTF for APAR VM66878 (CP), z/VM 7.3 provides guests with the ability to define simulated enhanced QDIO (EQDIO) network interface cards (vNICs) on the virtual switch. With this support, a guest has the option to establish and activate a network connection in either traditional QDIO or EQDIO mode. QDIO mode requires three devices to activate a network connection but EQDIO mode requires only a single device.

The following CP monitor records are updated:
  • Domain 8 Record 1 - MRVNDSES - Virtual NIC Session Activity
  • Domain 8 Record 2 - MRVNDLSU - Virtual Network Guest Link State - Link Up
  • Domain 8 Record 3 - MRVNDLSD - Virtual Network Guest Link State - Link Down

[7.3 VM66850] Transactional execution disablement

With the PTF for APAR VM66850 (CP), z/VM 7.3 provides support for transactional execution disablement. This support introduces a way to test application migration and detect usage of the transactional-execution facilities with z/VM 7.3, thus preparing z/VM 7.3 users for the eventual reduction and removal of support for these facilities.

The following topic is updated:
The following CP monitor record is new:
  • Domain 1 Record 37 - MRMTRFAC - Facility Alteration Events
The following CP monitor records are updated:
  • Domain 0 Record 19 - MRSYTSYG - System Wide Utilization Data
  • Domain 1 Record 4 - MRMTRSYS - System Configuration Data
  • Domain 4 Record 2 - MRUSELOF - User Logoff Data
  • Domain 4 Record 3 - MRUSEACT - User Activity Data

Miscellaneous updates for September 2025

The following topic is updated:

SC24-6301-73, z/VM 7.3 (June 2025)

This edition includes changes to support product changes that are provided or announced after the general availability of z/VM 7.3.

[7.3 VM66823, Start of changeVM66853End of change, Start of changeVM66857End of change] z/VM support for the IBM z17 family

With the PTFs for APARs VM66823 and Start of changeVM66853End of change (7.3 CP) and Start of changeVM66857End of change (7.3 RACF), z/VM 7.3 provides support for the IBM® z17® family. For more information, see z/VM support for the IBM z17 family in the z/VM: Migration Guide.

The following CP monitor records are new:
  • Domain 0 Record 25 - MRSYTPOW - Power Consumption Information
  • Start of changeDomain 6 Record 54 - MRIODVSE - Virtual Switch EQDIO QueuesEnd of change
The following CP monitor records are updated:
  • Domain 0 Record 20 - MRSYTEPM - Extended Channel Measurement Data
  • Domain 1 Record 4 - MRMTRSYS - System Configuration Data
  • Domain 1 Record 19 - MRMTRQDC - QDIO Device Configuration
  • Domain 4 Record 2 - MRUSELOF - User Logoff Data
  • Domain 4 Record 3 - MRUSEACT - User Activity Data
  • Domain 6 Record 21 - MRIODVSW - Virtual Switch Activity
  • Domain 6 Record 22 - MRIODVSF - Virtual Switch Failover
  • Domain 6 Record 25 - MRIODQDA - QDIO Device Activation
  • Domain 6 Record 26 - MRIODQDS - QDIO Device Activity
  • Domain 6 Record 27 - MRIODQDD - QDIO Device Deactivation
  • Domain 6 Record 34 - MRIODBPD - Virtual Switch Bridge Port Deactivation

[7.3 VM66825] z/VM Performance Data Pump enhancements

Performance Toolkit statement of support: The Performance Toolkit Data Pump dashboards have been updated to provide information that is specific to the new architectures delivered with the IBM z17 family of servers. The 3270 and web interfaces of the Performance Toolkit are stabilized at the IBM z16 architecture level and will not reflect new hardware and facilities delivered with the IBM z17 or any future families of servers.
With the PTF for APAR VM66825, z/VM 7.3 provides support for a new z/VM Performance Data Pump dashboard. The dashboard provides a graphical representation of IBM z17 family power consumption metrics from the z/VM monitor stream. The display includes information for the following components:
  • CPC
  • LPAR
  • CPU
  • I/O
  • Memory
The information can be used to calculate or approximate guest level apportionment.

Information about setting up Data Pump is available. See z/VM Performance Data Pump in z/VM: Performance.

Information is available about other services that process the Data Pump output stream, including links to Grafana sample dashboards. See z/VM Performance Data Pump.

[7.3 PH65377, Start of changePH67660End of change] z/VM TCP/IP support for enhanced QDIO

With the PTFs for APARs PH65377 Start of changeand PH67660,End of change z/VM 7.3 provides a native network device driver for the z/VM TCP/IP stack that uses enhanced QDIO (EQDIO) adapters for network transport. Start of change
Note: The EQDIO device driver requires the TCP/IP user ID to be configured to IPL ZCMS by default after the IBM z17 support has been applied.
End of change
The following topic is updated:
  • TCP/IP Monitor Records
    The following TCP/IP monitor records are updated:
    • TCP/IP MIB Record - Type '00'x - Sample Data
    • TCP/IP LCB Record - Type '05'x - Sample Data
    • TCP/IP Link Definition Record - Type '08'x - Configuration Data
    • TCP/IP Link Deletion Record - Type '10'x - Event Data

Miscellaneous updates for June 2025

The following topics are updated:

SC24-6301-73, z/VM 7.3 (September 2024)

This edition includes terminology, maintenance, and editorial changes.

The following table is updated:

SC24-6301-73, z/VM 7.3 (April 2024)

This edition includes changes to support product changes that are provided or announced after the general availability of z/VM 7.3.

[VM66758, VM66759] SCP identification enhancements

With the PTF for APAR VM66758, the z/VM Control Program (CP) can display identification information that is provided by guest operating systems. The CP display is similar to the HMC Systems Management "Partitions" display. SCP identification enhancements provide a means to determine what operating system a guest is running and also what guest operating systems have identified themselves since the z/VM system last IPLed.

The identification information is also provided in the following monitor records:
  • Updated record: Domain 1 sample configuration record 15 (MRMTRUSR), "Logged on User"
  • New record: Domain 4 event record 14 (MRUSESCP), "SCP Identification"

The following CP command is new:
  • QUERY SCPID (See QUERY SCPID in z/VM: CP Commands and Utilities Reference.)

With the PTF for APAR VM66759, z/VM's Control Monitor System (CMS) is enhanced. A user can change the CMS system identification information that a guest sends to the hypervisor.

The following CMS command is new:
  • SET SCPID (See SET SCPID in z/VM: CMS Commands and Utilities Reference.)

SC24-6301-73, z/VM 7.3 (September 2023)

This edition includes changes to support product changes that are provided or announced after the general availability of z/VM 7.3.

[VM66678, VM66709] Warning Track Interruption Facility

With the PTFs for APARs VM66678 (CP) and VM66709 (Performance Toolkit), z/VM 7.3 exploits a feature of Processor Resource/Systems Manager (PR/SM) called the warning-track-interruption facility. z/VM's exploitation of this facility helps improve guest response time and overall performance of workloads that are run on vertical-low or vertical-medium logical processors.

The following CP monitor records are updated:
  • Domain 0 Record 2 - MRSYTPRP - Processor Data (Per processor)
  • Domain 0 Record 19 - MRSYTSYG - System Data (Global)
  • Domain 1 Record 4 - MRMTRSYS - System Configuration Data
  • Domain 2 Record 7 - MRSCLSRM - Set SRM Changes
  • Domain 4 Record 2 - MRUSELOF - User Logoff Data
  • Domain 4 Record 3 - MRUSEACT - User Activity Data

SC24-6301-73, z/VM 7.3 (August 2023)

This edition includes changes to support product changes provided or announced after the general availability of z/VM 7.3.

[VM66687] z/VM Performance Data Pump

With the PTF for APAR VM66687, z/VM 7.3 supports z/VM Performance Data Pump.

z/VM Performance Data Pump (Data Pump) converts machine-readable z/VM monitor and SFS data into a generic text-based data stream. Modern tools can use the data stream to display real-time performance dashboards, aggregate real-time data for long-term usage analysis, or integrate with existing enterprise observability solutions.

Data Pump provides high-quality z/VM performance data to enterprise monitoring tools that are already deployed for application monitoring or capacity planning. Such tools align with skills and experiences of many users and offer integration with other tools and solutions.

Data Pump by itself does not deliver value that a user can readily use. To take advantage of Data Pump the customer must provision, configure, and deploy other services to process the data stream. While instructions for deploying the open source solutions are available, these components are not delivered with the z/VM product. For more information, see z/VM Performance Data Pump.

z/VM Performance Data Pump is licensed with Performance Toolkit for z/VM but does not support, depend upon, or interact with Performance Toolkit for z/VM in any way.

The following topicsn are new:
The following topics are updated:

SC24-6301-73, z/VM 7.3 (May 2023)

This edition includes changes to support product changes provided or announced after the general availability of z/VM 7.3.

[VM66424, VM66434, VM66650] Guest Secure IPL Support

With the PTFs for APARs VM66424, VM66434, and VM66650, z/VM 7.3 supports guest secure IPL (load and dump) for both ECKD and SCSI devices. A z/VM user can request that the machine loader validate the signed IPL code by using the security keys that were previously loaded by the customer into the HMC certificate store. The validation ensures that the IPL code is intact, unaltered, and originates from a trusted build-time source.

Support is provided for the following guest operating systems:
  • This support provides the ability for a Linux® guest to exploit hardware to validate the code being booted, helping to ensure it is signed by the client or its supplier.

    Linux on IBM zSystems instances that previously were able to perform secure boot first level on an IBM z15® or IBM LinuxONE III prior to Driver D41C Bundle S73a, or an IBM z16 or IBM LinuxONE 4 prior to Driver D51C Bundle S18, will no longer be able to use secure boot until appropriate additional support is applied to the Linux image. Details are available about the required service level of Linux to properly IPL securely first or second level after driver D41C Bundle S73a or Driver D51C Bundle S18 has been applied. See 230428 Machine Alert for 8561, 8562, 3931, 3932.

  • z/OS® is supported in audit mode only. Full exploitation requires Virtual Flash Memory support, which is not available to a guest. In audit mode, the IPL code is checked but the IPL continues even if the code is not valid.

z/VM and the z/VM stand-alone dump utility do not support performing host IPL via List-Directed IPL (LD-IPL) from ECKD. In addition, Secure IPL of the z/VM host and z/VM stand-alone dump are not supported.

The following CP monitor records are updated:
  • Domain 1 Record 4 - MRMTRSYS - System Configuration Data
  • Domain 1 Record 15 - MRMTRUSR - Logged on User
  • Domain 4 Record 2 - MRUSELOF - User Logoff
  • Domain 4 Record 3 - MRUSEACT - User Activity

SC24-6301-73, z/VM 7.3 (September 2022)

This edition supports the general availability of z/VM 7.3. Note that the publication number suffix (-73) indicates the z/VM release to which this edition applies.

Eight-member SSI support

This support increases the maximum size of a single system image (SSI) cluster from four members to eight, enabling clients to grow their SSI clusters to allow for increased workloads and providing more flexibility to use live guest relocation (LGR) for nondisruptive upgrades and workload balancing.

The following CP monitor record is updated:
  • Domain 1 Record 25 - MRMTRSSI - SSI Configuration

Change in location and size of the MONDCSS and PERFOUT saved segments

The default CP MONITOR MONDCSS saved segment starting virtual address has been changed to 1 GB and the size has been increased to 96 MB. The IBM Performance Toolkit PERFOUT saved segment starting virtual address has been changed to 1120 MB, immediately following the new MONDCSS. The reasons for these changes include:
  • Moving the segment starting locations addresses a problem with the Linux kdump configuration, which failed in a virtual machine with 1 GB of virtual memory that had attached one or both current versions of these segments.
  • Increasing the size of the MONDCSS segment accommodates the increased volume of CP Monitor data produced and provides room for its future growth.
These changes will not affect existing versions of these segments; they must be re-created for the new defaults to take effect.
The following topics are updated:

Miscellaneous updates for z/VM 7.3

The following topic is updated: