Perhaps the most interesting new feature for Xen 4.3 is the "Technology Preview" or experimental support for ARM-based processor virtualization. This support not only includes the current 32-bit variant, but also the upcoming 64-bit variant that will arrive with the ARMv8 architecture.
George Dunlap, a software engineer with Citrix, stated in a Xen.org blog post that the 32-bit port of Xen currently boots on the ARMv7 Fast Models, which includes the Cortex A15 platform. On this architecture, Dunlap writes, "It can boot dom0, create other virtual machines and it supports all the basic virtual machine lifecycle operations." Even though hardware for 64-bit ARM systems-on-a-chip (SoC) is not yet available, Dunlap said engineers also have Xen running well in 64-bit mode on ARMv8 Real-time System Models by ARM.
According to the announcement made by the Linux Foundation, developers working on the Xen Project collaborated with Calxeda and many other vendors to make sure Xen would work on ARMv7 and ARMv8 architectures. Servers using ARMv8 are expected to appear later this year and, more important, may show up in larger volumes during 2014. This type of support could be a deciding factor for bringing ARM-based servers into the Web-scale data centers of many of today's large Xen-based cloud providers like Amazon and Rackspace.
Lars Kurth, community manager for the Xen Project, added, "The ARM server support is an exciting development for the community and we're excited about the opportunities this will bring to customers."
It's unclear if or when VMware vSphere or Microsoft Hyper-V will support the ARM architecture. ARMv8 support in the Xen hypervisor could prove a challenge for VMware and Microsoft as they continue to compete with the free, community-supported alternative server virtualization platform and try to capture more of the growing cloud market share.
For a complete list of updates and enhancements, visit the Xen 4.3 feature list.
This article, "Linux Foundation releases open source hypervisor Xen 4.3," was originally published at InfoWorld.com. Follow the latest developments in virtualization at InfoWorld.com.