Single Root I/O Virtualization (SR-IOV)
Things to understand Beforehand
- Peripheral Component Interconnect Express (PCIe)
- RDMA, RNIC
- Hypervisor (KVM, vSphere)
SR-IOV (Single Root I/O Virtualization) is a specification that allows a single Peripheral Component Interconnect Express (PCIe) physical device under a single root port to appear as multiple separate physical devices to the hypervisor or the guest operating system.
SR-IOV uses physical functions (PFs) and virtual functions (VFs) to manage global functions for the SR-IOV devices. PFs are full PCIe functions that are capable of configuring and managing the SR-IOV functionality. It is possible to configure or control PCIe devices using PFs, and the PF has full ability to move data in and out of the device. VFs are lightweight PCIe functions that support data flowing but have a restricted set of configuration resources.
The number of virtual functions provided to the hypervisor or the guest operating system depends on the device. SR-IOV enabled PCIe devices require appropriate BIOS and hardware support, as well as SR-IOV support in the guest operating system driver or hypervisor instance.
