PCI-SIG SR-IOV Primer: An Introduction to SR-IOV Technology
IBM introduced virtualization on the VM/370 mainframe 30 years ago as a way to run multiple environments on one system. At the time, computing resources were expensive and allowing multiple environments to coexist meant that businesses didn’t have to invest in a second mainframe.
Today there is a different motivation driving the trend toward virtualization. With IA-based (Intel® architecture) servers, the price structure has changed so much that hardware cost is no longer the issue. Bigger problems are physical space in the data center, power/cooling costs, and management. The performance of the IA-based servers has also increased to a point where there is a large amount of idle capacity.
With virtualization, IT departments can utilize that spare capacity rather than adding a new physical server to support a new environment.
Adding the virtualization layer introduces overhead that consumes some of the idle capacity. There has been significant effort in the computing industry to address this overhead. Intel has introduced a set of processor, chipset, and Ethernet Controller enhancements defined under Intel® Virtualization Technology (Intel® VT) toward this end. Intel® VT improves the performance, efficiency, and robustness of virtualized platforms.
The latest trend is to develop complementary mechanisms in the I/O subsystem. The PCI-SIG* has developed the Single Root I/O Virtualization Specification (v1.1) to address sharing of I/O devices in a standard way.
Read the full PCI-SIG SR-IOV Primer An Introduction to SR-IOV Technology.