Overview

Single-root input/output virtualization (SR-IOV) is a PCI device virtualization specification that can divide a physical function (PF) into multiple virtual functions (VFs). These VFs share a PCI Express (PCIe).

For example, you can assign a VF NIC to a VM instance without considering the virtualization layer. Compared with traditional virtualization solutions, SR-IOV has the following advantages:

Shorten the data transmission path, improving the I/O performance of VM instances.
Reduce the consumption of host CPU resources, avoiding packet loss even a host has huge CPU load.