Chelsio Terminator T4/T5/T6 SR-IOV Virtual Function Ethernet NICs
The guest-side driver for virtual functions exposed by Chelsio's Terminator T4, T5, and T6 "Unified Wire" 10/25/40/100 Gbps server NICs when they are split up via SR-IOV. It lets virtual machines talk directly to a slice of a Chelsio adapter, and is mostly seen in datacenters and HPC environments that standardized on Chelsio gear.
recommendation
Worth keeping but documenting as a niche driver. Chelsio still sells T6 Unified Wire adapters new in 2025 and the code was receiving routine maintenance in netdev as recently as February 2025, so it is neither abandoned nor superseded. However, deployments are relatively low-volume compared to mainstream Intel and Mellanox NICs, so flagging it as legacy/specialist would help future maintainers gauge how much testing effort it warrants.
repository signals
sources
- lore.kernel.org
Recent upstream maintenance still touches cxgb4vf in netdev; the driver was part of a November 15, 2024 netdev patch series.
- lore.kernel.org
cxgb4vf was still being mechanically updated for kernel API churn in February 2025, showing it remains live in-tree rather than abandoned.
- cateee.net
CONFIG_CHELSIO_T4VF is the upstream Linux driver for Chelsio T4/T5/T6 Virtual Function Ethernet support and is still present through current kernel HEAD.
- chelsio.com
Chelsio's T6 Unified Wire Adapter product page advertises SR-IOV-capable hardware still marketed on the vendor site, indicating the family is not purely historical.
codex reasoning notes (technical)
Local source grep identified this as the cxgb4vf PCI SR-IOV VF NIC driver. lore_file_timeline on cxgb4vf_main.c showed activity through 2025-02-10 and substantive netdev/hardening touches in 2024, with no sampled evidence of a removal series; a follow-up lore_regex removal-subject query timed out rather than finding removal traffic. Web search returned LKDDb confirming current upstream support for T4/T5/T6 VF devices and an official Chelsio T6 product page still marketing SR-IOV adapters. Conclusion: hardware is still sold but niche, deployments are likely legacy/datacenter-low-volume, and there is no natural replacement other than keeping cxgb4vf for Chelsio SR-IOV VFs, so keep it but annotate as legacy/niche.