Xen 4.0.0 was released nearly one year ago (9 April 2010), but Xen 4.1.0 is now here to outdo that release.
Key features mentioned in the Xen 4.1 release notes include:
- A re-architected XL toolstack that is functionally nearly equivalent to XM/XEND
- Prototype credit2 scheduler designed for latency-sensitive workloads and very large systems
- CPU Pools for advanced partitioning
- Support for large systems (>255 processors and 1GB/2MB super page support)
- Support for x86 Advanced Vector eXtension (AVX)
- New Memory Access API enabling integration of 3rd party security solutions into Xen virtualized environments
- Even better stability through our new automated regression tests
The AVX support is welcome for those that are upgrading to Intel Sandy Bridge CPUs or AMD Bulldozers once released.
With Xen 4.1, the Xen dom0 and guest support is also available in most upstream Linux distributions to work unmodified. The dom0 support is with the vanilla Linux 2.6.38 kernel and then the rewritten Xen PV-on-HVM drivers were tacked on one release earlier, the Linux 2.6.37 kernel. There's also now upstream QEMU support for Xen.
It looks like a great release overall and may warrant some new Linux virtualization benchmarks. Xen 4.1 can be downloaded at Xen.org.