We are excited to announce the availability of Xen 4.22, the latest release of the Xen hypervisor. Xen 4.22 brings improvements across hardware support, scalability, and platform capabilities while continuing Xen's evolution as a trusted open source virtualization foundation for cloud, embedded, automotive, and safety-critical systems.
The release reflects the continued collaboration of developers, maintainers, and industry partners working together to advance virtualization in the open.
A more predictable support lifecycle
Alongside the Xen 4.22 release, the Xen Project continues its commitment to long-term maintenance with an updated stable branch support policy.
Xen 4.20 and later releases receive:
- Three years of full support, including bug fixes and security fixes
- Two additional years of security-only support
- Five years of security support in total
This change better aligns Xen's support model with the expectations of industries where products require long-term security maintenance, including embedded and automotive deployments.
Historically, Xen releases received approximately 18 months of full support, followed by security-only maintenance for up to three years from the original release. The updated policy extends full support to three years and total security support to five years.
Because the same lifecycle applies to every release, the project is intentionally not introducing separate LTS-branded branches. This gives users a consistent and predictable maintenance model without changing Xen’s release cadence.
What’s new in Xen 4.22
AMD Zen 5 support
Xen 4.22 adds support for AMD Zen 5 Bus Lock Threshold, helping protect system performance and responsiveness in virtualized environments. Bus locks caused by certain atomic operations can affect performance across an entire system. The new threshold support gives administrators greater control over how these situations are handled on modern AMD platforms.
Continued improvements for Arm
Arm has been a supported Xen architecture for many years. Xen 4.22 continues to improve Arm virtualization capabilities with enhancements including:
- PSCI suspend and resume support: Improves standards-based guest power management.
- FF-A updates: Improve communication with secure-world firmware and services.
- Armv8-R MPU work: Continues Xen's development for real-time and safety-critical systems without a traditional memory management unit.
Continued progress on RISC-V
Xen’s RISC-V port remains under active development as the community works toward full guest virtualization. Xen 4.22 adds internal support for the SSTC timing extension and introduces domain-building helpers that simplify the creation of guest domains using device trees. These are foundational improvements rather than a claim of production-ready RISC-V virtualization.
Xenstore improvements
Xen 4.22 introduces per-domain Xenstore quotas and watch-depth limits. These controls help prevent an individual guest from consuming excessive Xenstore resources and improve robustness in larger deployments.
Codebase modernization
Xen 4.22 also continues the long-term modernization of the hypervisor by removing deprecated interfaces and reducing technical debt. This work may be less visible than a new hardware feature, but it makes the codebase easier to maintain, review, and extend.
Built by the Xen community
Every Xen release is the result of collaboration across companies, organizations, and individual contributors. Developers review patches, test hardware, improve documentation, and solve problems together through an open development process.
Thank you to everyone who contributed code, reviews, testing, documentation, feedback, and persistence to Xen 4.22.
Want to join us and help build the future of open source virtualization? Join our Matrix channels and mailing lists.
Want to meet the people building Xen? Join the community at Xen Summit 2026 in Munich, September 15-17.