Xen.org has announced the availability of version 4.2 of its open source hypervisor – a fast, secure code base for operating system virtualization. This version includes new features and improvements in areas of security, scalability, performance, and documentation.

XL is now the default toolstack. According to the announcement, significant effort has gone into the XL toolstack for this release, and it is now the default. Additionally, the underlying libxl library has been improved and now supports the majority of the most common toolstack features, and the API has been declared stable.

Xen 4.2 now supports even larger systems, with up to 4095 host CPUs and up to 512 guest CPUs. And, according to the company, toolstack features such as the ability to automatically create a CPUPOOL per NUMA node and more intelligent placement of guest VCPUs on NUMA nodes have further improved the Xen experience on large systems. Additionally, security and documentation have been improved, with the XSM/Flask subsystem seeing several enhancements, including improved support for disaggregated systems and a rewritten example policy. 

Xen 4.2 supports a wide range of guest operating systems including Windows, Linux, Solaris, and various versions of the BSD operating systems. For more information, visit http://www.xen.org.