The Xen Project, hosted at The Linux Foundation, announced the release of Xen Project Hypervisor 4.9, an open source virtualization platform. The latest release focuses on advanced features for embedded, automotive and native-cloud-computing use cases, enhanced boot configurations for more portability across different hardware platforms, the addition of new x86 instructions to hasten machine learning computing, and improvements to existing functionality related to the ARM architecture, device model operation hypercall, and more.
Expanding Xen Project features in embedded and automotive
- The "null" scheduler, which enables use cases where every virtual CPU can be assigned to a physical CPU removing almost all of the scheduler overheads in automotive and embedded environments. Usage of the "null" scheduler guarantees near zero scheduling overhead, significantly lower latency, and more predictable performance.
- The new vwfi parameter for ARM (virtual Wait For Interrupt) allows fine-grained control of how the Xen Project Hypervisor handles WFI (Wait for Interrupt) instructions. Setting vwfi to "native" reduces interrupt latency by approximately 60%. Benchmarks on Xilinx Zynq Ultrascale+ MPSoCs have shown a maximum interrupt latency of less than 2 microseconds, which is extremely close to hardware limits and small enough for the vast majority of embedded use cases.
- Xen 4.9 includes new standard ABIs for sharing devices between virtual machines (including reference implementations) for a number of embedded, automotive and cloud native computing use cases.
For embedded/automotive a virtual sound ABI was added implementing audio playback and capture as well as volume control and the possibility to mute/unmute audio sources. In addition a new virtual display ABI for complex display devices exposing multiple framebuffers and displays has been added. Multi-touch support has been added to the virtual keyboard/mouse protocol (enabling touch screens).
Contributions for this release of the Xen Project hypervisor came from Amazon, AMD, Aporeto, ARM, BitDefender, Citrix, EPAM, Fujitsu, Huawei Technologies, Intel, Invisible Things Lab, Nokia, Oracle, Star Lab, Suse, Xilinx, Zentific, and a number of universities and individuals. The Xen Project continues to see contributions go up release after release. This release had 25% more contributors to the core hypervisor, and an increase of 17% of contributions coming from the hypervisor, tests, and other related components.