Monthly Archives: January 2012

XenSummit 2012: Dates, Location, PMC & CFP

Dear Community Members,

I am pleased to announce the date and location of the 2012 XenSummit in North America. It will be held from Aug 27-28, 2012 in San Diego, CA, USA. The event will be held immediately before LinuxCon North America 2012, at the same venue. You will find more information on the XenSummit events page.

Call for Participation

The CFP for XenSummit is now open. All submissions must be received before midnight May 1, 2012 PDT.


I will also again be looking for volunteers to join the Program Management Committee for XenSummit. As a PMC member you have the following responsibilities

  • Review submitted topics for the event (we will typically have 3 one hour calls and a bit of homework is needed)
  • Assist in compiling the final agenda for the event
  • If attending, introduce speakers – you don’t have to

Please get in touch with, if you want to join the PMC. We are aiming to have the first PMC meeting shortly after May 1st.


There are plenty opportunities of sponsoring the event. If you are interested, please contact

Please welcome Ian Campbell as Committer for Xen Hypervisor Project (ARMv7+VE)

Dear Xen Developers,

I wanted to announce that Ian Campbell from Citrix has been nominated and elected as Xen Hypervisor committer and will be responsible for the ARMv7+VE components in xen-unstable. We have seen an increasing number of patches to xen-unstable to enable support for the ARMv7 processor with virtualization extensions: 39 to be precise. So far, the Xen ARM port in xen-unstable is capable of booting a Linux 3.0 based virtual machine (dom0).

Ian has made a tremendous contribution to the project on which he worked almost since its creation. Ian was was one of the top contributors to the project for the last few years. Let me quote a few stats:

2010: 203 patches, changing 13101 lines of code
2011: 305 patches, changing 12225 lines of code

Ian also put together a build farm for the project that utilizes 10 Freescale i.MX53 Loco Quickstart boards (see picture). Besides working on the Hypervisor, Ian has also made significant contributions to the PVOPS project.

Congratulations Ian!

Xen 3.4.4 Update Release

I am pleased to announce the Xen 3.4.4 release, which is an update of the Xen 3.4.x series. This should be one of the most reliable releases since it is the latest maintenance release in the long term stable 3.4 branch that has had endured years of enterprise usage. The update release contains

  • Security enhancements including CVE-2011-1583
  • Support for AMD Family 15h (Bulldozer) CPUs
  • Performances and stability improvements
  • Various bux fixes

I wanted to thank Keith Coleman from N2 Servers, which offers high-availability managed Xen hosting with geographic redundancy, for maintaining the Xen 3.4 branch and leading this release.

Xen 3.4.4 is available for download from here!

Xen in Linux 3.2, 3.3 and Beyond

Linux 3.2
Linux 3.2 was released on Jan 4th and compared to earlier kernel releases, this one was very focused on fixing bugs reported by the community.

Thank you!!

Issues that caused lots of bug reports were:

  • The xen-platform-pci module (used for HVM guest to enable PV drivers) was frequently not included in the installer (that is now fixed by making it built in the kernel and fixing the installer builders).
  • ‘xl list’ vs ‘xm list’ discrepancy: this was caused by the guest not having the memory in the “right” sections.
  • Others were related to issues found with Amazon EC2, and bug fixes from Linux distributions (Debian, Canonical, Fedora, Red Hat, Citrix  and Oracle).
  • We also fixed boot issues for Dell machines.

We are all quite grateful for community reporting these issues! For reported issues, it might take some time to find the root cause. We do want to get them all fixed and hope that you will be patient with us.

On the “feature” side we

  • cleaned the code
  • added support for big machines with more than 256 PCI devices
  • added kexec support for PVonHVM (which sadly broke Amazon EC2, so we are going to redo them)
  • initial work laid out for HVM device driver domains
  • added features to support discard (TRIM or UNMAP) in the block layer along with the emulation of barriers

Linux 3.3
The Linux 3.3 merge window opened a week ago, and we had a similar pattern of patches: documentation cleanups (Thanks to the Document Day), security fixes, fixes in the drivers, driver cleanups, and fixes in the config options.

Feature wise a new driver for doing ioctl to the hypervisor was introduced, more infrastructure changes to improve the netback driver (grant table and skb changes), and making the netback driver be able to work in an HVM guest (the blkback is coming next). The graphic side introduced an DMA type pool code in the TTM backend (used by both radeon and nouveau to fetch/put all of the pages used by the adapter) so that it can work faster and also properly under Xen (the major issues were with 32-bit cards). i915 does not use TTM so it did not need this.

Linux 3.4 and beyond
So what is next? The top things we want to accomplish this year is to:

  • Make ACPI power management work with Xen.
  • Make netback work much much better than it does now!
  • Allow backends and xenstore to run in guests, allowing separate device driver domains
  • Improve the documentation
  • Fix more bugs!

There are other items on this list too, but these ones are the most important right now.

2012 Xen Event Calendar

We are working on the 2012 event calendar, and are actively seeking feedback and sponsorship support for Xen to be well-represented at industry events. Xen will be represented at the following events in the next few months

And of cousrse there will be XenSummits and presence in particular at Linux events, OSCON and others. However, plans for these are not yet finalized. We are also making good progress on the next XenSummit, targeting the week of Aug 27 in San Diego, CA. I  plan to finalize the venue and dates in the next few weeks.

Also, if you are hosting a local meetup or Xen event, please contact to have it listed and promoted on The same is true, if you want to host a Xen Hackathon.

Oracle hosted Xen Hackathon

I am pleased to announce the next Xen Hackathon. The Hackathon will be hosted by Oracle and takes place March 6-8, 2012 at the Oracle Campus in Santa Clara, CA, USA. If you want to attend, save the date and add yourself to the wiki. I wanted to thank Oracle and in particular Konrad Rzeszutek Wilk for making the Hackathon happen.

The aim of the Hackathon is to give developers the opportunity to meet face to face to discuss development, coordinate, write code and collaborate with other developers as well as allowing everyone to put names with faces. People working on documentation and other aspects of Xen, XCP, XenARM and related projects are also welcome.

There is no registration fee. However as an attendee you will need to cover your own travel, accommodation and other costs such as evening meals etc. More details will follow and will be communicated in due course on the blog, mailing lists and via the wiki page.

See you there!