KVM at Share St.Louis 2018

Yes, we will be at SHARE in St.Louis this August!
See our sessions in the Linux and VM track as follows:

• KVM on IBM Z (Session #23164): Latest news on our development work with the open source community
• KVM on Z Performance Analysis with Open Source Tooling (Session #23167): We will take a look at several tools and techniques to investigate KVM performance on IBM Z.
  

Knowledge Series: Managing KVM on IBM Z with oVirt

See here for a new entry in our "knowledge" series, providing step-by-step instructions on how to include IBM Z hosts in an oVirt data center.

Getting Started: RHEL 7.5 Instructions added

Instructions for RHEL7.5 were added to the Getting Started with KVM on Z series.
See here for the actual page.

Ubuntu 18.04 released

Ubuntu Server 18.04 LTS is out! Support for IBM Z is available here.
It ships

• Linux kernel 4.15,
• QEMU v2.11, and
• libvirt v4.0.

As obvious from these package versions, support for IBM z14 is readily in place.

Since this is a so-called LTS (Long Term Support) release providing approx. 5 years of support (in contrast to the usual 9 months of non-LTS releases), it is of particular interest to Ubuntu users interested in a stable environment for production deployments.

QEMU v2.12 released

QEMU v2.12 is out. Here are the highlights from a KVM on Z perspective:

• Added support for an interactive bootloader. As always, we strongly recommend to use the existing support in libvirt.
  To enable/disable, add the following element to your guest definition:
  
     <os>
       <bootmenu enable=’yes|no’ timeout=’n’/>
       ...
     </os>
  
  The timeout parameter specifies a timeout in milliseconds after which the default entry is chosen.
  Alternatively, set attribute loadparm to PROMPT to enable the boot menu without timeout in the respective disk's element:
  
     <disk ...>
       <boot order=’1’ loadparm=’PROMPT’/>
       ...
     </disk>
  
  Example:
  To enable the boot menu for 32 seconds for a guest using a libvirt
  domain XML format follows:
  
     <domain type=’kvm’>
       <os>
         <bootmenu enable=’yes’ timeout=’32000’/>
         ...
       </os>
• Exposure of guest crash information: When a guest is started using libvirt and crashes due to disabled wait, wrong interrupts or a program check loop, libvirt will print the information to the guest’s log, typically located at /var/log/libvirt/qemu.
  E.g. a crash due to a disabled wait results in an entry as follows:
  
     s390: psw-mask=’0xXXXXXXXXXXXXXXXX’, psw-addr=’0xXXXXXXXXXX
           XXXXXX’,crash reason: disabled wait
  
  Requires  libvirt v4.2.
• Added support for guests with more than 8TB of memory.

White Paper: Exploiting HiperSockets in a KVM Environment Using IP Routing with Linux on Z

Our performance group has published a new white paper titled "Exploiting HiperSockets in a KVM Environment Using IP Routing with Linux on Z".
Abstract:

"The IBM Z platforms provide the HiperSockets technology feature for high-speed communications. This paper documents how to set up and configure KVM virtual machines to use HiperSockets with IP routing capabilities of the TCP/IP stack.
It provides a Network Performance comparison between various network configurations and illustrates how HiperSockets can achieve greater performance for many workload types, across a wide range of data-flow patterns, compared with using an OSA 10GbE card."

This white paper is available as .pdf and .html.

RHEL 7.5 with support for KVM on Z available

Red Hat Enterprise Linux 7.5 is out. From the release notes, available here:

Availability across multiple architectures
To further support customer choice in computing architecture, Red Hat Enterprise Linux 7.5 is simultaneously available across all supported architectures, including x86, IBM Power, IBM z Systems, and 64-bit Arm.

Support for IBM Z is available through the kernel-alt package, as indicated earlier here, which provides Linux kernel 4.14. QEMU ships v2.10 via package qemu-kvm-ma, and libvirt is updated to v3.9.0 for all platforms.
Thereby, all IBM z14 features as previously listed here are available.
Check these instructions on how to get started.