Chelsio Terminator 6 inline IPsec offload
Hardware-accelerated IPsec encryption and decryption built into Chelsio's Terminator 6 (T6) family of 25/40/100 Gbps server NICs, such as the T62100-LP-CR and T6225-CR. It lets the network card encrypt VPN traffic in hardware as packets pass through, freeing the CPU for other work in high-throughput data centre and telco deployments.
recommendation
Worth keeping but documenting its niche audience: the T6 adapters this targets are still sold by Chelsio in 2025 and the code was actively maintained as recently as a January 2026 AES API update, with no removal discussion on the kernel mailing lists. Real-world deployments are likely small in number, since this is a specialty offload feature on a single vendor's high-end NICs, so a note pointing out which hardware actually exercises it would help future maintainers and packagers.
repository signals
sources
- lore.kernel.org
The driver file was still receiving upstream maintenance in 2026; a January 12, 2026 patch touched this code for an AES API update rather than removal.
- chelsio.com
The hardware family behind this driver is Chelsio's Terminator 6 (T6) ASIC.
- chelsio.com
Chelsio's current product site still lists T6 adapter SKUs such as T62100-LP-CR and T6225-CR and advertises integrated IPsec crypto support, indicating T6 hardware remained an orderable/current product line in 2025-2026.
- chelsio.com
Chelsio documents Linux inline IPsec offload on T6 adapters, including CONFIG_CHELSIO_IPSEC_INLINE and a T6225 adapter deployment example, showing the driver's exact use case is real hardware offload rather than dead code.
codex reasoning notes (technical)
Local source inspection (`rg`/`sed`) shows a real module driver implementing xfrmdev/IPsec offload, not helper code. `lore_file_timeline` on `chcr_ipsec.c` showed continued activity through 2026 with multiple 2025-2026 touches and no decay cliff; `lore_regex` for remove/deprecate/obsolete terms over the last 5 years returned no hits, so there is no evidence of active removal discussion. Web search + page open on Chelsio's official site identified the T6 family and current product listings, plus an official inline-IPsec deployment paper. Recommendation is `keep-annotate` because the driver is niche and hardware-specific with likely low modern deployment volume, but it is still maintained and tied to hardware that Chelsio continued to market/order in 2025-2026.