Posted by Scott Knowlton on December 16, 2012
Virtualization technology essentially componentizes a computer system into the following:
PCI Express with Single Root I/O Virtualization (SR-IOV) enables some of the virtualization to be done in hardware for the I/O devices instead of software, thereby streamlining the Virtualization Intermediary. Of course, hardware runs faster than software for the same function, so PCI Express with SR-IOV helps improve the overall system performance of a virtualized system.
To understand the benefits of PCI Express with SR-IOV, you can watch SolarFlare’s demo that was videotaped in the Synopsys booth at the Intel Developer’s Forum (IDF) conference in 2011 (shown below). The demo utilizes two servers running Citrix XenServer 6 to showcase the 3x in performance achieved when utilizing PCI Express 2.0 with SR-IOV virtualization technology. By incorporating DesignWare PCIe IP with SR-IOV, SolarFlare’s Dual Port SFP+ 10GbE Server Adapters were able to support hundreds of virtual PCIe functions and thousands of virtual NICs, thus reducing total hardware costs and power consumption, while increasing performance.
It’s tough to explain such complex technology in a blog posting, but in a nutshell, PCI Express with SR-IOV enables virtualization of a single physical I/O device to masquerade as multiple virtualized I/O devices, one for each virtual machine and with complete independence from each other. You can learn more about how virtualization benefits PCI Express by reading this whitepaper:
I’ve been involved in the development of PCI chips dating back to the NCR 53C810 and pre-1.0 versions of the PCI spec so have definitely lived the evolution of PCI Express and PCI since the very beginning! Over the years I have worked on variations of PCI, eventually moving on to architecting and leading the development of the PCI Express and PCI-X interface cores used in LSI’s line of storage RAID controller chips. For the last ten plus years I've also had the honor of serving on the PCI-SIG Board of Directors and holding a variety of officer positions. I am still involved in PCI-SIG workgroups and I present at many PCI-SIG events around the world. Back before the dawn of PCI, I received my B.S.E.E. from Rice University, and hold over two dozen U.S. Patents, many of which relate to PCI technology.