Monday, April 07, 2008

KVM Forum 2008 Call For Presentations

This is the Call for Presentations for the second annual KVM Developer's Forum, to be held on June 10-13, 2008, in Napa, California, USA [1]. We are looking for presentations on KVM development, quality assurance, management, security, interoperability, architecture support, and interesting use cases. Presentations are 50 minutes in length; there are also 25-minute mini-presentation slots available.

KVM Forum presentations are an excellent way to inform the KVM development community about your work, and to gather valuable feedback about your approach.

Please send your presentation proposal to the KVM Forum 2008 Content Committee at by April 20th.

KVM Forum 2008 Content Committee:

  • Dor Laor
  • Anthony Liguori
  • Avi Kivity


On a personal note, I found KVM Forum 2007 to be one of the best run conferences I've attended. The facilities were great and each talk was interesting. There was a great deal of discussion during each talk. Definitely worth the trip.

Sunday, April 06, 2008

KVM for the Mainframe

kvm-65 was released today. The most interesting feature in this release is support for the s390 architecture, more specifically, the System z9 line of mainframes.

The s390 is the grand-daddy of virtualization. Everything started there. In so many ways, everything we're doing with x86 virtualization is just playing catch-up. The new exciting features like hardware virtualization support and hardware paging support have been in s390 forever.

s390 clearly has a very mature hypervisor. What many people may not know though is that it's normal to run two hypervisors at any given time on s390. At the bottom level, there's PR/SM which divides the machine into rather coarse partitions. Within a PR/SM partition, you can run z/OS or Linux. You can also run z/VM within a PR/SM partition. z/VM is another hypervisor that allows for much more sophisticated features like memory overcommit and processor overcommit. The user has the ability to decide how much hypervisor they need to maximize the efficiency of their workloads.

Within a z/VM partition, you can run z/OS or Linux. The beauty of s390 is that this configuration has been supported in the hardware for many years and is very fast.

When Linux adopted native support for virtualization, it became obvious that this could be easily supported on the s390. The hardware has long supported this sort of nested virtualization and the implementation turned out to be very straight forward. It helps that the x86 virtualization extensions were inspired by a paper written about s370 almost 30 years ago :-)

What do you get from a platform that has supported virtualization for longer than I've been alive? In this very first release of KVM for s390, it already supports 64-way guests. After two years of development, we've just gotten to supporting 16-way guests on x86.