Xen 4.4 Brings Greater Virtualization Support to ARM

The latest release from the Xen Project brings performance and security improvements to more ARM-based server platforms.

Server makers and Web-based companies looking to build low-power ARM-based servers are getting more support with the release of the latest version of the Xen hypervisor.

The Xen Project, a group within the Linux Foundation that is pushing the development of the Xen hypervisor, on March 10 announced the availability of version 4.4 of the open-source technology, which includes among other performance enhancements wider support for ARM-based server platforms. Xen had been able to support ARM-based systems-on-a-chip (SoCs) since last year, but the new release will give system makers a better tool for bringing virtualization to ARM-based servers, according to officials with the Xen Project.

"Virtualization and low-powered servers are leading companies to rethink the data center and its potential for efficiency," Lars Kurth, chairman of the Xen Project advisory board, said in a statement. "Our solution contains IT-related costs, plus meets the security and scalability needs of today's elastic cloud, mobile and social networking companies. The latest updates continue the Project's track record of rich collaboration and widespread development from many of the world's technology leaders."

The Xen Project, which took over development of the hypervisor from Citrix Systems last year, in July 2013 released version 4.3, which included what officials said was experimental support for virtualization in ARM SoCs. The latest version includes even wider support for a range of platforms, including Applied Micro's 64-bit X-Gene ARM-based chip, the Arndale Board, Calxeda's ECX-2000, Texas Instruments' OMAP5 and the Allwinner SunXi boards. System makers can now more easily port the Xeon technology to new ARM SoCs, according to project officials.

Another improvement is 64-bit guest support on platforms using ARM's ARMv8 64-bit platform. Release 4.4 got key contributions from the likes of Advanced Micro Devices, Intel, Citrix, Oracle and SUSE Linux, officials said.

With the rise of such trends as hyperscale environments, cloud computing and big data, ARM officials and the company's partners see an opportunity to introduce a new low-power platform into parts of a server market that currently is dominated by Intel and its Xeon processors. Companies like Google, Facebook and Microsoft, which run massive, dense data centers that process huge numbers of small transactions, are looking for ways to put more compute power in the facilities without driving up energy costs.

ARM designs low-power SoCs and licenses the designs to chip-making partners like Qualcomm, Texas Instruments and Samsung, which put their own technologies on top of the designs and then sells the chips. The bulk of smartphones and tablets that ship today run on ARM-based chips, though Intel is looking to grow its presence in the market.

ARM officials and the company's partners for several years have been talking about making the move up the ladder into the data center, though little is being done by end users beyond testing systems. The release this year of the ARMv8-A platform—which brings with it more enterprise-class features like 64-bit computing and greater support for virtualization—could fuel the release of 64-bit ARM-based servers onto the market later in 2014 and into next year.

There already have been some key moves this year in that direction. ARM and its partners in January released the Server Base System Architecture (SBSA) specification, giving OEMs a framework for building systems powered by ARMv8-A SoCs. In addition, AMD this quarter will begin sampling its upcoming ARM-based eight-core Opteron A1100 "Seattle" chip, and Dell in February created a proof-of-concept microserver powered by Applied Micro's X-Gene.

HP also plans on using ARM-based chips in its growing portfolio of low-power Moonshot servers.

Proponents believe ARM-based chips can capture as much as 25 percent of the server market in the coming years. However, the chip maker and its partners are up against a motivated Intel with a lot of money and significant manufacturing and engineering capabilities. The company already has released its second-generation Atom chips aimed at the microserver space, and later this year will roll out its 14-nanometer "Denverton" SoC. In addition, the first of HP's Moonshot systems run on Atom chips.

Greater Xen support will only help ARM's cause. Release 4.4 promises a more stable version that can run more virtual machines on ARM-based servers, has improved management and interfaces, and has better performance and security capabilities from a virtualization mode called PVH that Oracle contributed.