As the hypervisor at the heart of CloudStack and Oracle VM (and formerly, OpenStack), Xen has received what the Xen Project characterizes as "major contributions" from the likes of AMD, Citrix, Intel, Oracle, and SUSE to support a broad range of hardware.
Xen has been running on ARM hardware before, but 4.4 widens the hypervisor's support for 64-bit ARM architectures. Newly supported ARM systems include AppliedMicro's X-Gene -- used in Dell's proof-of-concept ARM "microserver" -- the Calxeda ECX-2000, TI's OMAP5, and the Allwinner SunXi.
One co-development in this area, which the Linux Foundation claims is key to ARM support, is "the substantially improved multiplatform capabilities of the hypervisor," meaning that hardware vendors will be able to port Xen all the more rapidly to new system-on-chip designs as they are introduced.
Other changes introduced to Xen in 4.4 include "extended support for ARM-specific bootloaders and firmware interfaces, and support for physical partitions and LVM volumes to store disks of virtual machines." ARMv8 platforms with 64-bit guests are also now supported, and Citrix's own Xen development team has contributed back in an event-channel system to make Xen scale better in places like Amazon EC2.
Xen was formerly a Citrix project, but it was donated to the Linux Foundation in April 2013 as a way to provide it with a better environment for attracting contributors (Citrix donated CloudStack to the Apache Foundation for similar reasons). The donation seems to have paid off, not just in terms of advancement for Xen generally but in the way auxiliary projects have blossomed around Xen, such as the custom-built Mirage OS, created to run cloud-based applications.
Word of Xen being ported to ARM has been circulating since 2011, back when Xen was still under Citrix's stewardship. The effort to add ARM support originally involved targeting ARM's 32-bit ARMv7 architecture, using the Cortex A15 processor as a reference. But with ARM in the server advancing more quickly thanks to initiatives like the Open Compute Project's work, the pace has clearly picked up for both ARM and Xen.
This story, "Xen 4.4 is now fully armed for 64-bit ARM," was originally published at InfoWorld.com. Get the first word on what the important tech news really means with the InfoWorld Tech Watch blog. For the latest developments in business technology news, follow InfoWorld.com on Twitter.