Xen 4.20 introduces significant security updates, improved virtualization performance, and key enhancements that further solidify Xen’s position as a leading open source hypervisor.
SAN FRANCISCO – March 5, 2025 – The Xen Project, an open source hypervisor hosted by the Linux Foundation, today announced the release of Xen 4.20, delivering enhanced security, performance optimizations, and expanded architecture support for x86, Arm, and early staged support for RISC-V and PPC. The latest version introduces significant security updates, improved virtualization performance, and key enhancements that further solidify Xen’s position as a leading open source hypervisor for cloud computing, embedded systems, and enterprise applications.
“Security and performance remain at the heart of Xen’s development,” said Kelly Choi, Community Manager at the Xen Project. “Xen 4.20 represents a significant milestone in virtualization technology and empowers enterprises, cloud providers, and hardware vendors with high-performance solutions that meet the demands of modern enterprise infrastructure.”
The release of 4.20 positions Xen as the go to open source hypervisor to meet the security and performance demands of enterprise leaders and cloud providers. Xen 4.20 introduces improved security mechanisms, expanded processor support, and critical hypervisor refinements that make virtualization more robust and efficient. Compared to the previous release, Xen 4.20 features a performance boost for introspection tools, better device passthrough capabilities, and cache coloring. This release also introduces expanded support for modern enterprise architectures, with optimizations for Zen 5 processors. With a focus on usability and performance, Xen 4.20 makes virtual machine management seamless while reinforcing system security through comprehensive vulnerability mitigations.
During the 4.20 development window, 8 new Xen Security Advisories (XSAs) were published. These comprise:
Xen 4.20 has been developed with contributions from major industry partners, including AWS, ARM, AMD, HONDA, EPAM, Vates, and XenServer. This release reinforces Xen’s role in server virtualization, cloud infrastructure, security applications, and embedded systems.
The Xen Project invites developers, enterprises, and cloud providers to contribute to future releases and help drive the open source virtualization ecosystem forward. For more details on Xen 4.20, please visit: https://xenproject.org
"Citrix celebrates the release of Xen 4.20 and the significant advancements it brings to code safety and security across multiple architectures. This new release represents another major step forward in trusted virtualization technology. We are committed to working with the community to further the development of the Xen hypervisor, and to integrating these enhancements into the XenServer product so that our users continue to benefit from the robustness of open-source server virtualization."
– Diego Novellon, Software Engineering Manager, Citrix
"We are excited to see this new release happening. It comes not just with several notable improvements in terms of security, but also with a host of new features for alternative architectures and improved support for advanced boot options. All this and the arrival of two new strategic sponsors show a renewed interest and focus in the Xen Project. We expect 2025 to be a year of growth for our community and for the Xen ecosystem at large".
– Charles-H. Schulz, Chief Strategy Officer at Vates.
"The Xen 4.20 release marks significant progress towards functional safety compliance and broad automotive industry adoption. This is achieved through extension of technical requirements documentation, addition of system fuzzing, and expanded MISRA C support. EPAM is actively contributing to this advancement by addressing feature gaps, refining documentation, and everything that proves Xen's safety and determinism. Ultimately, these efforts will enable Xen to fully erase the gap between mission-critical embedded systems and high-performance computing through isolation and platform virtualization."
– Alex Agizim, CTO, Automotive & Embedded Systems
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About the Xen Project
The Xen Project, hosted by The Linux Foundation, is an open source hypervisor powering some of the world’s largest cloud platforms, embedded systems, and security applications. Xen’s flexible architecture enables high-performance, secure, and scalable virtualization solutions. The Xen Project community includes major industry contributors, researchers, and developers dedicated to advancing open source virtualization technology.
About the Linux Foundation
The Linux Foundation is the world’s leading home for collaboration on open source software, hardware, standards, and data. Linux Foundation projects are critical to the world’s infrastructure, including Linux, Kubernetes, LF Decentralized Trust, Node.js, ONAP, OpenChain, OpenSSF, PyTorch, RISC-V, SPDX, Zephyr, and more. The Linux Foundation focuses on leveraging best practices and addressing the needs of contributors, users, and solution providers to create sustainable models for open collaboration. For more information, please visit us at linuxfoundation.org
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