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Xen Project Releases Xen 4.22, Strengthening Open Source Virtualization for Cloud, Embedded and Automotive Systems

Written by The Linux Foundation | Jul 30, 2026, 1:00:01 PM

Latest release adds new x86 capabilities, advances Arm and RISC-V support, improves Xenstore scalability, and continues modernization efforts

Summary

  • The Xen project has announced the release of Xen 4.22, introducing key hardware enablement, including AMD Zen 5 support, guest suspend/resume power management for Arm, and SSTC timing extensions advancing RISC-V guest virtualization.
  • The release improves core platform performance and stability by preventing guest resource overconsumption in cloud environments using new Xenstore quotas while removing deprecated legacy interfaces.
  • Strengthened functional safety and automotive adoption is enhanced through functional safety testing with new software-in-the-loop tooling, supported by partners including Ford, Honda, Renesas, EPAM and Vates.

 

SAN FRANCISCO, July 30, 2026The Xen Project, an open source virtualization platform hosted by the Linux Foundation, today announced the release of Xen 4.22, the latest version of the open source Xen hypervisor. The release builds on the momentum of recent versions with key technical improvements, including broadened hardware support, improved core infrastructure and enhanced system-wide performance.

Advancements in Xen 4.22 ensure that hypervisors meet the growing demands of modern data centers, cloud environments, the automotive industry, embedded applications, and more. With this release, Xen delivers targeted virtualization benefits across enterprise and safety-critical industries. For data center and cloud environments, the platform provides efficient virtualization across multi-core servers through advanced cache management and resource handling to maximize scalability and lower overhead. In the automotive and embedded space, Xen continues to advance functional safety compliance and dom0less virtualization, enabling secure, reliable isolation for production-ready automotive platforms, infotainment, and driver-assistance systems.

"Xen 4.22 reflects the steady momentum of our community and our continued investment in the future of open source virtualization," said Cody Zuschlag, Community Manager for the Xen Project. "This release strengthens Xen across cloud, embedded, automotive, and safety-critical systems while continuing to modernize the project for today's hardware.”

Xen 4.22 expands hardware support across x86, Arm, and RISC-V platforms while introducing infrastructure improvements that enhance scalability and system robustness. The release also advances the project's long-term maintainability through continued codebase modernization, ensuring Xen remains a secure and reliable virtualization platform.

Core technical optimizations for scalability, efficiency and system robustness in version 4.22 include:

  • Xenstore and Infrastructure: Adds per-domain Xenstore quotas and watch-depth support to prevent resource overconsumption by individual guests, maximizing scalability for large deployments.
  • Modern x86 Platforms: Introduces AMD Zen 5 Bus Lock Threshold support to minimize system-wide performance degradation from improper atomic instructions.
  • Embedded and Arm: Enables guest suspension and resumption to RAM via standard PSCI for improved power management. Continues Armv8-R MPU support for safety-critical systems, and updates FF-A support to the v1.2 specification to streamline secure-world communication.
  • RISC-V Progress: Advances long-term foundational infrastructure toward future full guest virtualization by implementing internal SSTC timing extension support, and introducing CONFIG_DOMAIN_BUILD_HELPERS to simplify guest domain building via device trees.
  • Codebase Cleanups: Removes long-deprecated legacy interfaces to reduce technical debt and maximize focus on modern hardware platforms.

Xen 4.22 is available now. Users can download the release, review detailed release notes and documentation, join community discussions, or register for Xen Summit 2026, taking place from September 15-17 in Munich.

 

Supporting Quotes

“Xen 4.22 combines continued hypervisor evolution with important verification work from the Xen FuSa SIG. New QEMU-based Software-in-the-Loop tooling enables repeatable fault-injection testing and interface-behavior simulation, while non-instrumented code-coverage tooling supports assessment from basic coverage through modified condition/decision coverage. Combined with structured fuzzing, these capabilities improve defect detection and test quality for all Xen contributors and users, while building objective evidence for mission-critical deployments.”

– Artem Mygaiev, Technology Solutions Director, EPAM

“Partnering with Xen Project and the Linux Foundation Mentorship program has been an accelerator for Ford innovation. Our first-ever mentee has embraced the technology and the opportunity to make a difference in the adoption of new features.”

Paulette Avolio, Open Source Program Leader, Ford Motor Company

"As vehicles become increasingly software-defined, a secure, reliable, and flexible virtualization foundation is essential for integrating workloads with different requirements on a common computing platform. Xen 4.22 represents another important step forward for open source virtualization, strengthening the foundation needed to support the evolving demands of automotive systems. Honda looks forward to continuing its collaboration with the Xen Project community and contributing to an open ecosystem that accelerates innovation across the automotive industry.”

– Kazuo Tsubouchi, Executive Chief Engineer, Honda R&D Co., Ltd.

"The Xen 4.22 release continues to strengthen the foundation for software-defined vehicles and mixed-criticality automotive systems. With ongoing enhancements for Arm-based platforms, including improvements in virtualization robustness and power management, Xen continues to evolve as a key enabling technology for next-generation automotive computing. Renesas is pleased to support the Xen community and its commitment to open-source innovation."

– Aish Dubey, Vice President, Renesas Electronics

"What makes Xen matter is the community around it, and 4.22 is that community at work: hardware enablement, functional safety and long-term maintainability moving forward together. Vates is glad to carry a large share of the load this cycle, the RISC-V bring-up in particular, and to do it in the open alongside the rest of the project.”

– Charles Schulz, Head of Strategy, Vates

"The Xen 4.22 release highlights the continued strength of open-source innovation, delivering meaningful performance, scalability, and reliability enhancements for modern cloud and data center environments. Innovations such as the newly introduced Flexible Return and Event Delivery (FRED) specification lay the foundation for improved CPU efficiency and future performance gains. for all XenServer based deployments. Citrix remains deeply committed to the Xen community, helping bring these advancements to enterprise customers through a more performant, resilient, and trusted XenServer platform.”

– Jose Augustin, Senior Director, Product Management, Citrix | XenServer

About the Xen Project
Xen Project software is an open source virtualization platform licensed under the GPLv2 with a similar governance structure to the Linux kernel. A project at The Linux Foundation, the Xen Project community is focused on advancing virtualization in a number of different commercial and open source applications including server virtualization, Infrastructure as a Services (IaaS), desktop virtualization, security applications, embedded and hardware appliances. It counts many industries and open source community leaders among its members including AMD, Arm, AWS, Epam, Ford Motor Company, Honda, Renesas, Vates, and XenServer (Citrix). For more information about the Xen Project software and to participate, please visit XenProject.org.

 

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