Xen Winter Meetup 2025: a recap
We just wrapped up the Xen Winter Meetup 2025. It was an amazing opportunity to push Xen forward in a way that can only happen when people get together in person. Organized entirely by Vates, we hosted it at the University of Grenoble IMAG building, a great spot for cutting-edge research in computer science and virtualization. Our goal? Accelerate Xen’s development, bring in fresh minds, and foster stronger ties between industry and academia.
🐼 Why we did it
The idea for this meetup started at the last Xen Summit, where a design session revealed how much progress can be made when we sit down and tackle challenges head-on. Xen Summit itself is fantastic, with deep technical talks and important roadmap discussions, but we wanted to take things further. There’s something special about in-person brainstorming that no online discussion can replace.
We decided to double down on what makes the Xen community great: collaboration, innovation, and a shared passion for building a better virtualization stack. Furthermore, we found an opportunity to expand our reach. Xen needs more contributors. However, developers often don’t even realize they can get involved. By hosting this meetup, our objective was to make it easier for people—especially students and researchers—to step in, learn, and contribute.
Grenoble was the perfect location to realize our objecctives. The city is home to some top-tier research teams, like KrakOS at LIG, who specialize in virtualization, OS design, and cloud infrastructure. We knew bringing Xen developers and researchers together would spark new ideas and open doors for up-and-coming contributors. With seasoned Xen devs mentoring newer ones, we’re keeping knowledge sharing alive and ensuring the stability of the project for years to come.
A fully independent Xen meetup
We also wanted to prove that a Xen-focused event could be community driven without high-cost partners while remaining accessible to all. Hosting it ourselves meant we had full control over the agenda, keeping the focus 100% on what benefits the Xen community. We didn’t need a huge budget: just amazing people with a shared commitment to making Xen better.
And of course, we didn’t just talk about it—we did it. If you’ve been following our journey, you know we’re all about action:
Olivier Lambert
⏩ A packed but well-paced meetup
We ran the Xen Winter Meetup over two days, striking a balance between structured sessions and free-flowing discussions. Mornings were packed with talks, where developers and researchers shared their latest work, while afternoons were all about design sessions: getting hands-on and tackling real technical challenges together.
We were very pleased with the format. Too often conferences cram in endless back-to-back talks, leaving everyone mentally drained by the end of the day. We wanted something different, something that kept the energy high and made room for actual problem-solving. By keeping the mornings focused on presentations and reserving the afternoons for in-depth discussions, we avoided mental burnout and got the best of both worlds.
The main talks
As planned, I kicked things off with a quick intro talk, covering why we organized this event and some logistics details—nothing groundbreaking, so I’ll spare you the slides.
From there, Kelly (Xen Community Manager) gave us a Xen Project weather report, looking at recent successes and transformations within the project. It was a great way to set the stage for what’s ahead and highlight how Xen continues to evolve.
Then we got into the meaty technical talks. Teddy (Vates) gave an insightful presentation on Rust within the Xen Project, showcasing the work being done to bring memory safety and modern tooling into the hypervisor. Andrew (Citrix) followed with an overview of key improvements and opportunities in the Xen Hypervisor, essentially laying out a roadmap for where we need to focus our efforts in the coming months and years. This talk is definitely one to keep in mind, as it’s going to serve as a reference for major Xen development moving forward.
Andrei (Vates) then took the stage to go over our progress on getting AMD SEV support into Xen, a critical piece for enhancing security and workload isolation. On Friday, Piotr (3MDeb) presented a fascinating talk on host Secure Boot for XCP-ng, showing how it can be done properly—and within a week, they already had a working proof of concept! It was really engaging to see just how thin the layers between hardware, firmware, and Xen/XCP-ng really are.
We also had some great contributions from academia. Léo (University of Rennes) gave a talk about using Xen to analyze VM memory without being detected by malware—a true cat-and-mouse game between attackers and defenders. Caleb (University of Grenoble) followed with his research on Xen’s behavior when migrating between heterogeneous CPUs. This isn’t published yet, but once it is, we’ll definitely share more details in a future post!
Back to Xen development, Thierry (Vates) provided a recap of the Q35 work and what’s next, with some valuable insights from Andrew on key architectural decisions. Finally, Julien (Clever Cloud) wrapped up the talks with a real-world use case, showing how they use XCP-ng + Xen Orchestra (Vates VMS) in their PaaS platform, and how it could help businesses migrate away from VMware.
Every talk brought something unique to the table, making it clear that Xen’s ecosystem is alive, evolving, and tackling exciting challenges head-on!
Design sessions: an essential tool for collaboration
One of the biggest strengths of this meetup was the design sessions. These weren’t just regular talks—they were interactive, hands-on discussions where we reconfigured the room, formed a big circle, grabbed a whiteboard, and got straight to problem-solving. This setup made a huge difference. Instead of just listening, everyone actively contributed to shaping Xen’s future, discussing architecture, features, and the next steps for key developments. All while leaving room to deep dive into any challenging topics.
A lot of important topics were tackled: PVH virtualization mode, nested virtualization, and the Xen IOMMU we’re bringing upstream. The second day opened up even more diverse discussions, with a dedicated session on “Getting Started with Xen’s Codebase”, making it easier for newcomers to contribute, and another on “Strengthening Collaboration Between Xen and Academia”, which led to concrete action points.
These sessions didn’t just help move technical topics forward—they helped build stronger relationships between teams from different companies and universities. And that’s the real magic of these events and the greater Xen community. When people connect and collaborate in person, the effects ripple far beyond the meetup itself. We believe the relationships built here will make upstream development smoother and more efficient, ensuring that Xen continues to evolve with input from a diverse and engaged community.
It was also about cheese and computers
A Winter Meetup in the Alps without cheese? Not happening. So, of course, we organized a proper fondue night, because what better way to wrap up intense discussions than by almost drowning in melted cheese (we survived… barely).
These social moments are just as important as the technical ones. When you step away from deep-dive discussions and just hang out, real connections start to form. And that’s what makes long-term collaboration easier. When you’re working with people across time zones and only interacting through screens, having shared memories from a night like this changes everything. It’s no longer just “someone from another company” on the other side of an email—it’s someone you’ve had a laugh with, debated with, and maybe even fought over the last piece of bread.
The Xen community is diverse and thriving. It's a place where folks from all walks of life can come together and work towards a common goal and passion. These special moments let this wide variety of folks connect and hopefully build lasting bonds. The community is welcoming and ready to accept new contributors!
At the end of the day, these meetups aren’t just about code: they’re about strengthening the Xen community as a whole, and sometimes, all it takes is a good meal to turn colleagues into actual friends.
What about computers, and very old ones? What’s a meetup full of virtualization and OS enthusiasts without a deep dive into computing history? We couldn’t pass up the chance to take everyone to ACONIT, home to one of the most incredible computer collections in the world.
From the very first machines of the 19th century to rare and iconic hardware like mainframes, early IBM computers, analog machines, and legendary personal computers, the visit was a time-travel experience through the evolution of computing. Seeing these machines up close—some of which laid the groundwork for everything we work on today—was a humbling reminder of how far we’ve come.
And let’s be honest, for a room full of tech people, this was geek heaven. It was another highlight of the meetup, adding a unique touch that made this gathering not just about Xen, but about celebrating the whole history of computing.
🎯 Our take on the meetup
First off—huge kudos to everyone who made this happen! A big thanks to all the attendees; nearly everyone who signed up showed up, despite flu season trying to mess with our numbers. Out of a max capacity of 50, we had 47 people in the room. That was seriously impressive for such a deep technical gathering in Grenoble.
This wouldn’t have been possible without the University of Grenoble generously hosting us and, of course, the amazing Vates team, who made sure everything ran smoothly so that we could focus on discussions, not logistics.
Beyond just being a great moment for the Xen community, this meetup proved something important: a Xen board member can organize a high-impact gathering at a very reasonable cost, all while accelerating real collaboration. No need for huge conference budgets—just the right people, the right topics, and a shared drive to move Xen forward.
In the end, we achieved all of our goals. We brought more people together around Xen’s future, and the mix of attendees was incredible: IaaS providers, hardware manufacturers, academic researchers, software vendors, and experts—all in the same room, actively shaping what’s next.
This wasn’t just a meetup. It was a step forward for Xen’s long-term success and we’re incredibly proud of what we built together.Thanks for coming and we look forward to the next meetup!
