Outreach Program Projects

From Xen

The Xen Project is a Linux Foundation collaborative project that develops the

  • Xen Hypervisor (for x86 and ARM) - the bulk of this page. IRC channel #xendevel
  • Unikraft (see #Unikraft). IRC channel #unikraft
  • Mirage OS (see #Mirage_OS). IRC channel #mirage
  • We also have some infrastructure, tooling and community related projects that run across all the sub-projects. These are slightly different from other projects, in terms of skills: see #Infra_and_Community

The project also has excellent relationships with its upstreams (Linux Kernel, the BSDs, QEMU and other projects) and upstreams such as Linux distributions. This is reflected in the project list, which contains many interesting cross-project development projects for applicants.

Finding a project that fits you

This page lists Xen Project development projects for Google Summer of Code and Outreachy (formerly the Outreach Program for Women). But projects can be picked up by anyone! If you're interesting in hacking Xen Project code and want to become a part of our friendly developer community this is the place to start! Ready for the challenge?

To work on a project:

  • Send an email to the relevant mailing list (see Developer Mailing Lists) and let us know if you are interested in starting to work or applying on a specific project.
  • Post your ideas, questions, RFCs to the relevant mailing list sooner than later so you can get comments and feedback.
  • An easy way to get started (and show that you can set up the Xen Development Environment, fix an issue, build and test Xen, submit a patch, etc.) is to address a suitable number of Coverity Scan issues.
  • Small Contribution Requirement: Outreachy requires that youfulfil the Make a Small Code Contribution Requirement. This is not strictly necessary for GSoC, but a small contribution to the project during the application period gives you an advantage

You have your own project idea: no problem!

  • If you have your own project idea, outline what you are trying to do on the mailing list. If you know the right list, post your project idea on mailing list. Failing that post on xen-devel and we can redirect you to the right list. Make sure you add Outreachy <round> or GSoC <year> to the subject line.

It is a good idea to ...
The Xen Project has participated in Outreachy and Google Summer of Code (GSoC) in the past. One of the things we learned by participating in these programs is that you will be more successful, happier and get more out of participating in internship programs, if you do a bit of prep-work before writing an application. Here is some stuff you can do:

  • Contact your mentor early and get to know him or her
  • Start hanging out on our IRC channels (#xendevel, #unikraft, #mirage)
  • You may want to ask the mentor for a couple of small bitesize work-items (such as reviewing someones patch, a bitesize bug, ...) and start communicating on the relevant mailing list. That helps you become familiar with our development process, the mentor and other community members and will help you chose the right project and help you decide whether the Xen project is for you.
  • Note that quite a few Xen maintainers used to be GSoC participants once. Feel free to ask community dot manager at xenproject dot org to put you in touch with them if you have questions about their experience.
  • Any work you submit before applying for a project should be based on xen-unstable development tree, if the project is Xen Hypervisor and/or tools related. Linux kernel related patches should be based on upstream kernel.org Linux git tree (latest version). Mirage OS patches should be based on the right codeline too. Check out the navigation by audience section on the left to find resources.

More resources

Quick links to changelogs of the various Xen related repositories/trees: Please see XenRepositories wiki page!

Before to submit patches, please look at Submitting Xen Patches wiki page and the relevant Xen Project team page. This will contain more information.

If you have new ideas, suggestions or development plans let us know and we'll update this list!

Aspiring Participants

  • Please contact the mentor and CC the most appropriate mailing list
  • Get a bite-size task from the mentor before the application starts
  • If you feel comfortable with an idea, please put your name to an idea using the following format
|Review=(delete as addressed)
* {{Comment|~~~~:}} I am interested in this idea ... 
                    (note that you may also want to link to the e-mail thread with the mentor)
  • You will need to request write access to the wiki by filling out this form

Outreach Program Project Ideas

List of peer reviewed Projects

Xen Hypervisor Userspace Tools

golang consumer for the `xenlight` golang package

Date of insert: 28/01/2020; Verified: 17/02/2022; GSoC: yes
Technical contact: George Dunlap <george.dunlap@citrix.com>, IRC nick: gwd
Mailing list/forum for project: Make sure you CC xen-devel@lists.xenproject.org on all communications; tag mails with [GSoC] or [Outreachy] as appropriate#
IRC channel for project: #xendevel
Difficulty: Straightforward
Skills Needed: Familiarity with the Go language
Description: The `xenlight` golang package consists of golang bindings for libxl, a robust library designed to be able to drive all necessary interaction with a Xen system; it's the library on which both xl and libvirt-xen are written.

The golang bindings are nearing completion, and so this project would be to create an in-tree consumer of those bindings; partly as an example, partly to be useful. Ideas include:

  • A simple `host status` daemon which would present information about the host: memory available, domains running, and so on
  • A 'system stress tester', which would perform random operations (create / destroy / migrate / suspend VMs, create / destroy / migrate cpupools, &c) in quick succession to test the robustness of the system
  • A re-implementation of the 'xl' command in Golang, suitable to be used as a drop-in replacement in our test system
  • A 'wrapper' library to make creation of guests simple and straightforward, with a minimum of boilerplate
Applicants are encouraged to come up with their own ideas as well.
Outcomes: A useful project or library which exercises and demonstrates how to use the `xenlight` golang package.

Xen Toolstack

Xen Hypervisor

Xen on ARM: Performance Counters Virtualization

Date of insert: 01/02/2019; Verified: 01/28/2020; GSoC: Yes
Technical contact: Stefano Stabellini <sstabellini@kernel.org>, IRC nick: sstabellini; Julien Grall <julien@xen.org>, IRC nick: julieng
Mailing list/forum for project: Make sure you CC xen-devel@lists.xenproject.org on all communications; tag mails with [GSoC] or [Outreachy] as appropriate
IRC channel for project: #xendevel
Difficulty: Hard
Skills Needed: Good C, assembly, and kernel programming skills
Description: Performance counters are a family of ARM registers used to measure performance. Today they are not virtualized by Xen, they are just trapped and implemented as read-as-zero/write-ignore, see xen/arch/arm/arm64/vsysreg.c and xen/arch/arm/arm64/vsysreg.c. This project is about properly virtualizing these registers, so that guests can use them to measure their own performance. It involves saving and restoring the performance counters registers in Xen during VM context switch.
Outcomes: Xen guests can use performance counters.


Verified: 15/02/2021

Unikraft is a unikernel build system that enables developers to build light-weight services starting from a highly customizable library base. (for more information see here).

We keep an up-to-date list of Unikraft-related projects as issues on github here. If you're interested in one of them, or have project suggestions, please write us at <simon.kuenzer@neclab.eu> and <felipe.huici@neclab.eu>, cc minios-devel@lists.xenproject.org.

Mirage OS

Several different projects (follow link)

For Mirage OS, please check out the list of Mirage OS projects where help is needed. If you are interested in one of these projects, please e-mail mirageos-devel@lists.xenproject.org and CC the mentor from the page (the project will contain a link to the mentor's GitHub account, which normally contains an email address and IRC information). You can also ask questions on the #mirage IRC channel and usually find mentors on there.


No projects at this stage.

Infra and Community

We also have some infrastructure, tooling and community related projects that run across all the sub-projects. These are slightly different from other projects, in terms of skills and working with the community. Please check extra information below the project.

New Project Ideas

Please add new project ideas here, following

Conventions for Projects and Project Mentors

Rules and Advice for Adding Ideas

  • Be creative
  • Add projects into New Project Ideas or improve projects in Project Ideas that Need Review or more work through review comments.
  • Use the {{GSoC Project}} template to encode ideas on this page. Please read the Template Documentation before you do so.
  • Be specific: what do you want to be implemented; if at all possible provide an indication of size and complexity as described above to make it easier for an applicant to choose ideas
  • If you are willing to mentors those ideas, add your name and email to the idea.
  • Aspiring mentors should introduce themselves on the most appropriate Xen Project mailing list

Peer Review Goals

We strongly recommend and invite project proposers and project mentors to review each others proposals. When you review, please look out for

  • Can an intern get going and started with the information in the project description
  • Are any unstated assumptions in the proposal, is there undefined terminology, etc. in the proposal
  • Can the project completed in 3 months (assume that one month is needed for preparation)
  • Does the project meet Google Summer of Code goals, which are
    • Create and release open source code for the benefit of all
    • Inspire young developers to begin participating in open source development
    • Help open source projects identify and bring in new developers and committers
    • Provide interns the opportunity to do work related to their academic pursuits (think "flip bits, not burgers")
    • Give interns more exposure to real-world software development scenarios (e.g., distributed development, software licensing questions, mailing-list etiquette)

Peer Review Conventions

The {{GSoC Project}} template used to encode project listings, contains some review functionality. Please read the Template Documentation before you add a template, also please use the conventions below to make comments.

|Review=(delete as addressed)
* {{Comment|~~~~:}} Comment 1
* {{Comment|~~~~:}} Comment 2

Choosing Projects

We have a bi-weekly mentor meeting overlooked by our program management team, which are a core team of 2-3 mentors and a program administrator. This group will work with mentors to ensure that project proposals are of good quality and whether mentors are engaging with the program management team and particpants in the weeks before the application period ends.