Here's a tidbit I learned about from Dave Kowalsky. Thanks Dave!
At its annual conference in SanJose, the PCI Special Interest Group detailed updates and extensions to the PCI Express specification that could drive annual silicon updates through 2007. The SIG outlined six new directions for Express, taking the serial technology into areas such as security and virtualization.
The SIG announced plans to extend the Express spec for virtualized I/O. The extension will allow multiple operating systems to access the same physical I/O resources either simultaneously or in serial fashion. The spec will define supersets for accessing I/O in a single or in a multihost environment.
Software virtualization is seen as a key technique for making best use of the multicore, multithreaded processors beginning to proliferate in the PC market. Advanced Micro Devices and Intel are rolling out separate techniques for virtualizing their multicore processors. With the new spec, the SIG will extend those capabilities to Express-based I/O devices. Designers think virtualization ultimately will be applied to all PC systems — even multitasking home computers. But its first target is server blades that are evolving towards stateless collections of compute boards in a single chassis linked on an Express mezzanine bus. The virtual I/O spec will allow those compute cards to share Express, Ethernet and storage I/O resources in and outside their chassis.
The spec is still in an early stage, with the 19-company working group about to put a requirements document out for review. A completed spec is not expected until late in 2006 or early in 2007. It will also require hardware changes for chip makers who want to support its features.