libvirt v.3.5.0 released

libvirt v3.5.0 is now available for download at the libvirt project website.
A new z Systems-specific feature is the introduction of parameter loadparm for boot devices.
The loadparm parameter can be used to select a specific boot configuration from the zipl menu when IPL’ing/booting from a boot device, similar to what the chreipl command does in Linux on z.
Being able to select a configuration from multiple boot configurations provides more flexibility and allows to recover from error situations by booting a "last known good configuration".
To use, specify the loadparm attribute for a boot device in a guest's XML as follows:

   <disk>
      <boot order='1' loadparm='3'/>
      [...]
   </disk>

Note that this feature requires the forthcoming QEMU 2.10 release.

libvirt v.2.5.0 released

libvirt v2.5.0 is now available for download at the libvirt project website.
A highlight for the z Systems platform support in this release is scsi_host hostdev passthrough, improving throughput by providing a libvirt frontend for scsi_host devices.

KVM for IBM z Systems v1.1.2 released

KVM for IBM z Systems v1.1.2 is out today! See here for the respective blog post on Mainframe Insights, and the following pages for the formal announcements: US, Canada, Asia-Pacific, Japan, Latin America and Europe.

It ships with QEMU v2.6 and libvirt v1.3.3. Here is a list of highlights from a KVM on z perspective:

• Enhanced SCA support
  Exploit up to 248 CPUs per KVM guest
• SIE capability
  Expose SIE availability in /proc/cpuinfo as follows:
  
     $ cat /proc/cpuinfo | grep features
     features        : esan3 zarch stfle msa ldisp eimm dfp edat etf3eh
                       highgprs te vx sie
• STP host toleration
  Previously, Server Time Protocol (STP) had to be turned off in the host. In case of time differences, the TOD clock is adjusted in a smooth manner, avoiding jumps.
• Improved removable media support
  Allow to boot KVM guests seamlessly from ISO9660 media.
• OASIS VIRTIO v1.0 support
  Support OASIS OASIS standard for virtio devices.
• CPU hotplugging
  Allow to add CPUs dynamically to a running guest
• STHYI support: Added the z/VM-defined Store Hypervisor Information instruction (STHYI) for KVM guests. See also here.

libvirt 1.3.5 released

libvirt v1.3.5 is now available for download at the libvirt project website.
The list of highlights improving z Systems platform support is as follows:

• virt-host-validate: Added support for the s390 platform. This tool detects virtualization capabilities of a host, and can verify capabilities for a specific hypervisor such as QEMU.
• Added a panic device model for s390. This new device model allows to represent the z Systems architecture's guest panic capabilities. A panic device is useful to receive guest panic events.