The SR-IOV standard allows efficient sharing of PCIe devices among IO Guest Domains. An SR-IOV device can have hundreds of Virtual Functions (VFs) associating with a Physical Function (PF). The creation of VFs can be dynamically controlled by the PF through registers designed to turn on the SR-IOV capability. By default, the SR-IOV capability is turned off, and the PF behaves as traditional PCIe device.
Devices that have SR-IOV capability can take advantage of the following benefits:
Performance – Direct access to hardware from virtual machines environment.
Cost Reduction – Capital and operational expenditure savings include:
Power savings
Reduced adapter count
Less cabling
Fewer switch ports