Quotes of the week

It looked quite like a fork in the Xen 1.x days, since it also contained lots of Linux device
drivers, etc. It still pulls in a fair bit of Linux code for a) utility functions (spinlocks, generic
datastructures..) and b) low level hardware support. However, the rest of the code is often
extremely different from Linux since it uses different abstractions and interfaces - there's
enough core Xen-specific code added and core Linux code removed that it really looks like
a very different animal.

I think it would be better to question whether the combination of Xen + dom0 constitutes a
fork of Linux with some code moved about to funny places and some extra protection
domain crossings. I think that would be a highly valid question to ask, though as usual, it's
quite not that simple :-S

I'm skeptical whether (especially with improving hardware support for virtualisation) Xen's
approach is going to (continue to?) hold much merit over its competitors. Equally, it seems
to be still making good progress in functionality and a lot of people use it. It'd be nice to
see it finally merged in kernel if it can be done tastefully - the out-of-tree code is causing
people pain at the moment, which is always the problem with such things!

Disclaimer: Have worked on Xen, still do research related to it.