It was back in December of last year that I talked about the virtualization solution called Kernel-based Virtual Machine (KVM) being added into Linux kernel 2.6.20. The Linux 2.6.21 kernel then improved on the support for paravirtualization with the full featured addition of Virtual Machine Interface (VMI).

Now, if that weren't enough, the upcoming 2.6.23 kernel release will feature two new virtualization frameworks. The 2.6.23 kernel will be merging in support for both Xen (the more popular of the two) and lguest.

Xen is described as a popular virtual machine monitor (VMM) for x86-compatible computers that can securely execute multiple virtual machines, each running its own OS, on a single physical system with close-to-native performance. The project was originally started as a research project at the University of Cambridge, and today is backed by commercial support from XenSource.

Simon Crosby, CTO of XenSource, said on his blog that "it has been a tremendous, collaborative effort to get the patches upstream by all of the kernel community. The effort for XenSource has been led by Jeremy Fitzhardinge, who has tirelessly tracked the developing kernel versions, while adding the Xen guest support for SMP guests, with fast paravirtualized block and network I/O. Next up is 64 bit support, according to Jeremy, who is also working on Dom0 support." Simon continued to say that this work will allow future Linux distro kernels to "automatically inherit Xen support, without needing to pull the Xen paravirtualization patches into their kernel as a separate effort."

And lguest is described as "a simple hypervisor for Linux on Linux. Unlike kvm it doesn't need VT/SVM hardware. Unlike Xen it's simply 'modprobe and go'. Unlike both, it's 5000 lines and self-contained." The lguest patches are written and maintained by Rusty Russell who says, "Lguest is designed to be a minimal hypervisor for the Linux kernel, for Linux developers and users to experiment with virtualization with the minimum of complexity. Nonetheless, it should have sufficient features to make it useful for specific tasks, and, of course, you are encouraged to fork and enhance it."

Posted by David Marshall on July 21, 2007 12:43 PM