SR-IOV and Virtual Functions

SR-IOV — Hardware Virtualization for NICs

Single Root I/O Virtualization (SR-IOV) is a PCIe specification that lets a single physical NIC present multiple Virtual Functions to the operating system. Each VF appears as an independent NIC with its own MAC, its own RX/TX queues, and its own PCIe configuration space. A 100 GbE NIC might expose 32 or 64 VFs, each receiving a slice of the underlying bandwidth. Critically, VFs have direct DMA access to memory — there is no hypervisor or virtual switch in the packet path. For a UPF container that needs line-rate access, attaching a VF gives the container hardware-grade NIC performance,…