NVIDIA Mellanox mlx5 Scalable Function auxiliary devices
Scalable Functions are a lightweight virtualization mechanism on NVIDIA Mellanox ConnectX and BlueField networking hardware, letting one physical adapter expose many independent network interfaces to containers, VMs, or DPU workloads without full SR-IOV overhead. They are common in modern datacenters and BlueField-2/3 DPUs and SmartNICs.
recommendation
It should stay because the underlying ConnectX and BlueField-3 hardware is actively sold by NVIDIA in 2025, the SF deployment model is documented in current NVIDIA DOCA guides, and upstream patch traffic touching this code is still landing as recently as late 2025 and early 2026. There is no replacement driver upstream, and SR-IOV is an architectural alternative rather than a substitute.
repository signals
sources
- spinics.net
A net-next patch posted on 2025-11-16 updates SF dev-table notifier registration for mlx5, showing ongoing upstream work in this area rather than retirement.
- spinics.net
A net patch posted on 2026-01-20 fixes an mlx5 initialization bug in the same subsystem window, consistent with active maintenance through 2026.
- docs.nvidia.com
NVIDIA's 2026 BlueField SF guide documents creating, configuring, and deploying `mlx5_core.sf.*` auxiliary devices, showing SF is a current supported deployment model.
- docs.nvidia.com
The BlueField-3 platform guide lists BlueField-3 DPU and SuperNIC SKUs/specifications, indicating the underlying mlx5 hardware family is still a current product line.
codex reasoning notes (technical)
Local shell inspection of `driver.c` shows a real `auxiliary_driver` for `mlx5_core.sf`, not a helper library. Local `git -c safe.directory=... log` shows substantive touches through 2026-01-29. Web search was used because `lei` is unavailable here: spinics/netdev results show active 2025-11 and 2026-01 patch traffic touching this SF area, and I found no removal/deprecation thread in the same searches. NVIDIA docs found by web search show SF deployment instructions in 2026 and current BlueField-3 DPU/SuperNIC SKUs, so this is still sold and deployed, but mainly in datacenter/DPU/SmartNIC niches rather than mass commodity systems. No direct replacement upstream driver exists; SR-IOV VFs are an architectural alternative, not a driver replacement.