SLES 12 SP5 released

SLES 12 SP5 is out! See this section in the release notes for a detailed look at IBM Z-specific changes in support of KVM.
Otherwise, the update ships the following code levels:

• Linux kernel 4.12 (SP4: 4.12, unchanged),
• QEMU v3.1 (SP4: v2.11), and
• libvirt v5.1 (SP4: v4.0).

See previous blog entries on QEMU v2.12 and v3.0, and libvirt v4.7 and v4.10 for further details on new features that become available by the respective package updates.
Also take note of this article, which adds further details on IBM z15 support.

Documentation: New Performance Papers

Two new performance papers on KVM network performance were published:

• Best Practices and Tuning Recommendations
• Exploitation of IP Routing

See also the Performance Hot topics page in IBM Knowledge Center.

QEMU v4.2 released

QEMU v4.2 is out. For highlights from a KVM on Z perspective see the Release Notes.

Webinar: Dynamically provisioning resources to KVM hosted Linux virtual servers

Abstract
Are you just getting started with KVM? In this session we review dynamic provisioning and de-provisioning processor, memory, disk storage, and network connectivity to your KVM host and the guest virtual servers. Examples include both graphical management and command line interfaces. Come and see how simple it can be to manage your servers.

Speaker
Richard Young, Executive IT Specialist, IBM Systems

Registration
Register here. You can check the system requirements here.
After registering, you will receive a confirmation email containing information about joining the webinar.

Replay & Archive
All sessions are recorded. For the archive as well as a replay and handout of this session and all previous webcasts see here.

Documentation: KVM Virtual Server Management Update

Intended for KVM virtual server administrators, this book illustrates how to set up, configure, and operate Linux on KVM instances and their virtual devices running on the KVM host and IBM Z hardware.

This major update includes information about VFIO pass-through devices, virtual server setup with the virt-install command, setting up virtual switches with VNIC characteristics, and other features that are available with the latest versions of QEMU and libvirt.

You can download the .pdf here.

Ubuntu 19.10 released

Ubuntu Server 19.10 is out!
It ships

• Linux kernel 5.3,
• QEMU v4.0, including support for the IBM z15 CPU model
• libvirt v5.4.

For a detailed list of KVM on Z changes, see the release notes here.

KVM on IBM z15 Features

To take advantage of the new features of z15, the latest addition to the IBM Z family as previously announced here, use any of the following CPU models in your guest's domain XML:

• Pre-defined model for z15
    <cpu mode='custom'>
      <model>gen15a</model>
    </cpu>
• Use z15 features in a migration-safe way (recommended). E.g. when running on z15 this will be a superset of the gen15a model, and feature existence will be verified on the target system prior to a live migration:
    <cpu mode='host-model'/>
• Use z15 features in a non-migration-safe way. I.e. feature existence will not be verified on the target system prior to a live migration:
    <cpu mode='host-passthrough'/>

Here is a list of features of the new hardware generation as supported in Linux kernel 5.2 and QEMU 4.1, all activated by default in the CPU models listed above:

• Miscellaneous Instructions
  Following the example of previous machines, new helper and general purpose instructions were
    minste3     Miscellaneous-Instruction-Extensions Facility 3 
• SIMD Extensions
  Following up to the SIMD instructions as introduced with the previous z13 and z14 models, this feature again provides further vector instructions, which can again be used in KVM guests.
  These new vector instructions can be used to improve decimal calculations as well as for implementing high performance variants of certain cryptographic operations.
  In the z15 CPU models, the respective feature is:
    vxpdeh      Vector-Packed-Decimal-Enhancement Facility
    vxeh2       Vector enhancements facility 2 
• Deflate Conversion
  Provide acceleration for zlib compression and decompression
  In the z15 CPU model, the respective feature is:
    dflt        Deflate conversion facility
• MSA Updates
  z15 introduces a new Message Security Assist MSA9, providing elliptic curve cryptography. It supports message authentication, the generation of elliptic curve keys, and scalar multiplication.
  This feature can be exploited in KVM guests' kernels and userspace applications independently (i.e. a KVM guest's userspace applications can take advantage of these features irrespective of the guest's kernel version).
  In the z15 CPU model, the respective feature is:
    msa9        Message-security-assist-extension 9 facility
    msa9_pckmo  Message-security-assist-extension 9 PCKMO
                subfunctions for protected ECC keys

The z15 CPU model was backported into several Linux distributions. It is readily available in RHEL8.1, SLES 12 SP5, SLES 15 SP1 (via maintweb updates for kernel and qemu) and Ubuntu 18.04.