Monthly Archives: May 2013

Five Chances to Hear About the Xen Project in the Next Two Weeks

Over the next two weeks, there are no less than five great opportunities to hear about the Xen Project.  These include:

The Linux Link Tech Show on May 29, 2013

Xen Project Evangelist Russ Pavlicek will be a guest of The Linux Link Tech Show crew.  This weekly webcast is streamed live at 8:30 PM EDT (GMT-4) worldwide, with downloadable podcasts available soon after the show is over.  They also have a lively IRC during the broadcast, so join in while you listen and maybe answer some questions others may have about Xen!

LinuxCon Japan: “10 Years of Xen and Beyond” on May 30

Xen Project Community Manager Lars Kurth talks about the history and future of the project at LinuxCon Japan.  LinuxCon Japan is a great Linux Foundation event for the Asian region.  And Lars will be available frequently on the expo floor, so stop by and say hello!

Texas Linux Fest: “How to (Almost) Kill a Successful Project and then Bring It Back to Life: Lessons Learned from the Xen Project” on June 1.

Russ speaks to the Texas Linux Fest crowd about how Xen’s early success was nearly overcome by disconnection with the community, and how the problems were addressed.  Texas Linux Fest continues to create an excellent event for the south central US.  If you are in the Austin, TX area, give yourself a treat and sign up!

Southeast Linuxfest: June 7 & 9

Russ reprises the talk from Texas to the North Carolina crowd on Friday, then finishes on Sunday with “Xen Project: a 10th Anniversary Status Report“.  SELF has a long history of delivering high quality conferences to those in the US southeast.  If you can make it to Charlotte, NC, make sure you stop in on the sessions and talk to Russ.

We really hope that most folks can attend one of the sessions, or at least download the audio, video, or slides as they are made available.

Remember that these and many other upcoming events can be found in the Events Calendar.  Check there often to see who will be speaking in a venue near you.


Event Report : Xen Hackathon 2013

After almost a week in Dublin, we’re back with a debrief of the Xen Hackathon. Please note this is from our point of view (Xen Orchestra team) and that we’re not kernel or hypervisor hackers.

Google Docks: our place to work

We were really impressed by Google’s building (Google Docks). The atmosphere was really relaxed, with a lot of small places to work, and a very good food at lunch (for free!). The space dedicated to Hackathon was fantastic: on the 11th floor, no offices, and a very very exceptional view on Dublin, all around us. Oh, and a very big terrace… We can’t have any excuses regarding our productivity 😉

Thanks to Guido for the organization and the opportunity to be here!

A nice view of the Google Docks building.


One of thing that was very interesting was that a lot of people who are doing Open Source software here were paid by -very- big companies (Google, Oracle, Citrix, etc.). We felt very small comparatively, but at the Hackathon, people were not “representing” a company. You’re just a hacker working on a project. In my opinion, that’s the magic of Free and Open Source Software: everyone can contribute, there is no bureaucracy or hierarchy. If your project responds to a need, you’ll have people around you, no matter where you from. We felt the Bazaar model was very present at this event. Continue reading

Bringing Xen on the Chromebook and the Arndale Board: the journey so far

I’ve started to work on the Xen on ARM project by trying to get Xen running on the nice little Samsung Chromebook which run an ARM processor with the virtualization extensions. The Chromebook uses Exynos 5250 dual core platform with 2GB of RAM, which could be perfect for a good demo of Xen on ARM.

But porting Xen to new ARM platform without any useful debug output of some kind was really hard at the beginning. There is no accessible serial port available on the Chromebook and Xen cannot display anything on the screen. But there is a trick, write your log to specific area in RAM, and read it back after a reboot. It is really annoying, does take more time to have any feedback from Xen and you don’t know when you can reboot the machine to get those logs. This is how we did it, until we received an Arndale Development board.

So, we started the development on Chromebook by simply installing a Linux on it (on an SD card). There were few tutorial on internet, so it was not too hard. Then we recompiled a kernel, as it will be needed to integrate dom0 support. And last, we tried to understand how to use the bootloader on the machine to load Xen where we need it to be and execute it, it took some time and many tries. When we finally get something from Xen, we could continue make it work on the Chromebook. We had bugs like loading Xen at the wrong place in RAM or missing information in the device tree. Then it took sometime to load Linux correctly and we had to use some hack to actually find the Linux blob in memory as the default bootloader was not very helpful for that.

We found several problems were a page table was written in the middle of the binary in memory because of too many hack on how to load Linux for dom0. Before starting to work with the Arndale, we’ve been able to run some of Linux code, but fail early in Linux when it tried to load the device tree.

The Arndale board finally arrived, we had to start over, different bootloader and this time there is a serial port!! The Arndale use the same hardware platform, namely, the Exynos 5.

So first thing, how to start Xen on it? It appears to be relatively easy to load your own kernel, Xen here. So let’s hack a serial driver for Xen, in assembly first :-). We found out that the bootloader delivered with the board does not let Xen switch to hypervisor mode, so we had to recompile a u-boot for the board. Not a big deal, Linaro has done some work on the board as well, so we could get u-boot from their source tree and finally have Xen get its hypervisor mode.

After the first bits resolved, we could get along and figured out all the hack/fix needed in Xen in order to run it on this second platform, the first one was a Versatile Express. There were a lot of assumption about the hardware. So to get things running, we just replace those by others because having a proper way to handle different platform take a lot of time.

We had an issue with the time on this platform. The ARM Generic Timer was not working, it was always giving the same time. After trying to use the Multi-Core Timer of the Exynos platform, we realise there was the same, but we had to set a bit in the MCT register in order for the timer to start counting.

After resolving few other issues, we could finally get a prompt! Next, we worked on getting more, like starting few guest.

There is yet another hack for both the Arndale and the Chromebook to get a working network interface or having something on the screen of the Chromebook, it’s a 1:1 mapping of the memory of dom0. This is when the virtual address (seen by dom0) match the physical address (seen by the hardware). Normaly, those two addresses are different for any guest.

To conclude, it has been a lot of fun working on those two. We could get a working demo for both the Arndale and the Chromebook of Xen capabilities. There is still a lot of work ahead of us, but we are getting there.

Much more happened in the latest weeks, during which I concentrated on something different than Xen on ARM or the Chromebook. For instance, there is now a better multi-platform support in Xen and SMP support is getting there as well.

Here is some wiki page on how to get started:

Xen 4.3.0-RC2 Available and Xen TestDay Tomorrow

A new RC of the Xen Hypervisor has just been announced by our release manager with this message on the xen-devel mailing list.

In addition to the usual repository tagging (xen-4.3.0-rc2), a tarball is available (and here’s its signature).

This happened right in time for the second Xen Test Day of the 4.3 release cycle, which will be held tomorrow (Wed, 22nd May), on the #xentest channel on freenode… So come and bring friends!

Find out Xen 4.3.0 RC2 specific testing information and indications on the Wiki page: Xen 4.3 RC2 test instructions. More information about Xen Test Days in general in this other one.

After tomorrow, there is another Test Day planned already for June 4th.


Transition from to

This is just a quick note to you all, to outline the transition and timetable from the old main website to the new site. Other sites, such as,, and others will follow.

What will happen?

The site, will be moved to and all pages will clearly be marked as archived. We will redirect:

The intention is that web searches for xen and xen project will lead to the new website, while making sure that the old content is still available. Also, we want to ensure that linkx to will not be broken.

What has already happened?

We already created and set up the infrastructure for redirects. We also have a list of proposed redirects to We also removed all links to from

What is next?

We will be testing redirects on some of the less used pages in the coming days. Once we are confident, that all this works we will activate the redirects. The plan is to do this on June 8th.

How does this impact me?

Fundamentally, there should be no significant impact. If you check the Xen web pages regularly, you will be redirected to a corresponding new page or the archive.

If you have web real estate that links to, links will just be redirected to the new website. Although no links will be broken, you may want to …

  • Double check whether redirects go a location that matches your content
  • Ensure that links go to the new xenproject site (instead of the archived version)

If you are a vendor that is listed in the Xen Eco-system Pages, you are likely to see referrals from impacted. Thus, we would want to encourage you to create a new directory entries in the Xen Project Directory (which you can now do yourself, by creating a listing). We migrated static eco-system pages in the project and research categories (as these are more static). However we expect that other categories (Products, Consulting and Hosting) are owned (and changed as needed) by the respective vendors that provide a product or service.

Welcome Home: Xen moves to a new home built by

In April, Xen unveiled a new community site at Xen Project leaders worked closely with in the development of their new online home, built using Joomla. is the official host of and one of the countless cloud-based companies that benefits from Xen technologies. Thousands of users launch free trials of the Joomla CMS through the company’s  platform every month and the Xen Hypervisor is at the center of it all. It’s the critical component that provisions compute and allows for Joomla application virtualization.

When the Xen Project needed a new, more collaborative home on the web, project leaders ultimately decided to build using Joomla. Lars Kurth, Community Manager, said that,  “in a nutshell, the Joomla back-end is a lot easier to use and to get started with than Drupal. That makes it ideal for a community site where you want volunteers to be able to do contribute.” Lars also added that “Joomla is relatively intuitive when you need to figure out how to get stuff done.”

Mark Hinkle said that “ is in the unique position of having a strong hosting presence combined with an intimate knowledge of the Joomla! CMS + Application Framework, developer ecosystem and the Joomla! open source community.” He further commented that “we chose for numerous projects because of their broad knowledge and their dedication to supporting the underlying open source community as well as their skill at developing interactive websites that foster participation from the users of those sites.” CEO Gary Brooks commented that “we were very excited to work with Xen on this project. We obviously share similar open source values and we both contribute to open source collaborative communities. Without Xen, our company wouldn’t exist. We’re defining what we think ‘cloud’ means, and Xen produces the technologies that drive our highly available, scalable applications. We are the prime example of what’s possible with Xen, a poster child of sorts.”

About the author: Ryan Bernstein is the Chief Operating Officer at and an adjunct professor of composition and public speaking at Northwestern Michigan College in Traverse City, Michigan.