A couple of weeks ago I went to Copenhagen to attend Linaro Connect and Ubuntu Developer Summit for the first time. I was really impressed by the size of the conference, I wasn’t expecting so many people, it certainly rivals LinuxCon in terms of attendance.
All the best minds in the ARM world together in the same hotel for a week: the list of attendees includes Arnd Bergmann (Linaro), Olof Johansson (Google), Grant Likely (Linaro), David Rusling (Linaro), Jon Masters (Red Hat) and many others. You can imagine the level of technical discussions that was going on.
Last weekend Linus Torvalds pulled the Xen on ARM patches in his Linux tree, so as of Saturday the 7th of October, we have Xen ARM in upstream Linux!
This makes Xen the first hypervisor supported by Linux on the ARM platform!
Working on ARM has been a very pleasant experience for me: the documentation of the hardware is well written and complete, the virtualization extensions are useful and fit our architecture very well, the ARM emulator comes with a nice debugger that helped me figure out some of the most difficult problems I had.
But beyond the hardware and the development tools, I was really impressed by how welcoming the Linux ARM Community has been to me: from the invite to the ARM session at the Kernel Summit, to the guidance through the upstreaming process and in general the feedback I received to my work. Nowadays, the Linux Community is usually perceived as not being friendly to newcomers, but it hasn’t certainly been the case for me! In particular I would like to thanks Arnd Bergmann, Marc Zyngier, and the Linaro folks. It has been great working with you. I would also like to thank Konrad Rzeszutek Wilk because he went out of his way to help me upstream my ARM work: I couldn’t have done it without him.
As the Xen on ARM patches were pulled by Linus, I was also appointed as Xen ARM maintainer in the Linux kernel. This is a new responsibility for me and I am not going to take it lightly. I am looking forward to work closely with Arnd, Russell, Konrad and the other Linux maintainers to make Linux the best operating system to run virtual machines and inside virtual machines on Xen on ARM!
While Xen on ARM in Linux is certainly a major milestone, there are still a lot of things to do. Right now I am busy trying to run Xen on a Cortex A15 Versatile Express development platform while Ian Campbell already started the ARMv8 Xen port!
Stay tuned if you want to run Xen 64-bit on ARM.
If you are interested in the Xen on ARM project, you might want to read the slides of the presentation I gave at XenSummit 2012:
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.
Over the next few days I will be putting out highlights from this year’s Xen Summit in Boston. Many interesting projects, concepts, and “Xen deployments” were presented and I want to share some of these with you. I will also be setting up a new page on Xen.org that contains a list of active Xen development projects to better allow the community to find interesting work to spend your time on.
I want to start my Xen Summit commentary by promoting the Samsung announcement of their release into Open Source of the Xen port for the ARM processor. The project is now live and actively being tracked at http://wiki.xensource.com/xenwiki/XenARM and there is a xen-arm mailing list also available. I will be posting the presentation from Samsung along with the video which includes a great demonstration of moving a DomU from one prototype mobile device to another later today so be sure to check back to the Xen Summit tab on Xen.org later today.