An update of the open-source Xen Hypervisor to v4.5 brings reduced footprint, increased power efficiency, and new “experimental” real-time services.
According to an announcement on the Xen Hypervisor project’s blog, the version 4.5 release brings 43 major new features and includes the most updates in the project’s history. Of particular interest to designers of embedded and mobile gizmos, despite the fact that v4.5 adds 78KB of new code, it also eliminates 141KB, resulting in a slimmer and more efficient inner Xen.
“The net effect of a skinnier Xen Project Hypervisor code base is increased usability, simplicity and innovation,” says the project’s blog post. “This is all by design and one of many steps we’ll continue to take to fine-tune our development and release cycle.”
Through its many enhancements and new features, Xen 4.5 “creates new opportunity to incorporate Xen virtualization into software stacks in markets like embedded computing, automotive, drones, avionics and more,” continues the post. “New developments with hyper scale-out computing, Internet of Things, NFV/SDN, and next-generation ARM-based products are driving increased demand for better resource sharing and utilization with enough flexibility to efficiently grow well into the future.”
Xen 4.5 includes several enhancements that can improve the power efficiency and real-time performance of mobile and embedded devices.
One is the implementation of PCSI 0.2 (Power State Coordination Interface) support. This, says the project’s post, “is important in embedded environments where power consumption needs to be kept to the absolute minimum. It allows us to power down/up CPUs, suspend them, etc.”
Another significant enhancement is the “experimental” inclusion of RTDS real-time scheduling. RTDS (Real-Time Deferrable Server) is described as “a real-time CPU scheduler built to provide guaranteed CPU capacity to guest VMs on SMP hosts.”
Real-time Xen architecture
(click image to enlarge; source: RT-Xen project presentation)
This change apparently resulted from the work of the RT-Xen project, and is described in this presentation [PDF].
Version 4.5 also adds supports for several new ARM processors, including TI’s OMAP5 and DRA7, Samsung’s Exynos 5250, Exynos 5 Dual, Exynos 5420, and Exynos Octa, and AllWinner’s A20/A21, to name a few.
“Virtualization will soon become the norm rather than the exception in automotive, avionics, mobile, multimedia, and other fields where predictability and high-end, real-time support are critical,” states the Xen project’s post. “Xen wants to play a big role in this, and this new scheduler will allow for such.”
Xen and the art of AGL
Nautilus architecture with Xen as hypervisor, Linux or QNX as RTOS, and Android for apps
(click image to enlarge)
The Embedded and Automotive initiative integrates GlobalLogic’s Nautilus IVI and telematics platform with an embedded version of Xen, to enable sandboxed implementations of Android (for IVI) and either QNX or Linux for telematics and other back-end automotive services.
The Xen Hypervisor Project is hosted by the Linux Foundation. More details are on the Xen Project website.