Subject: Re: [PATCH 0/3] Add packet-mode ESP offload for Airoha/EIP93

From: Jihong Min <[email-masked]>
Date: Sat, 23 May 2026 21:24:00 +0900

On 5/23/26 21:15, Jihong Min wrote:
> This series adds the missing plumbing for ESP offload engines that
> operate on whole ESP packets instead of only exposing AES/HMAC through
> the crypto API AEAD interface.
> 
> The normal ESP software path can already call into accelerated AEAD
> algorithms, but packet-mode engines such as EIP93 can also generate and
> consume ESP packet framing: padding, pad length, next header and ICV.
> That needs a slightly different XFRM offload contract so the netdev
> driver can hand the skb to a packet backend rather than trying to make
> hardware fit the software trailer layout.
> 
> Patch 1 extends the ESP offload infrastructure for packet engines while
> preserving the existing behavior for drivers that do not opt in.
> Patch 2 exposes an EIP93 ESP packet backend for encapsulation and
> decapsulation.
> Patch 3 wires Airoha Ethernet GDM netdevs and DSA user ports to that
> backend through xfrmdev_ops. ESP GSO and ESP TX checksum offload remain
> disabled.
> 
> Runtime testing was done on a Gemtek W1700K2 running OpenWrt with the
> same changes applied on top of a 6.18.31-based kernel.
> 
> Test parameters:
> 
>   - Static IPv4 transport-mode XFRM SAs between the AP and host.
>   - ESP transform: auth hmac(sha1), enc cbc(aes) with a 128-bit AES key.
>   - iperf3 TCP test, AP as client and host as server:
>         iperf3 -c <host_ip> -P 4 -t 10
>   - The host always used normal Linux XFRM software processing.
>   - With AP ESP offload disabled, the AP also used the Linux XFRM
>     software path; in this setup, EIP93-backed AEAD crypto was still
>     available to that path.
> 
> Network-relevant test setup:
> 
>   - AP: Gemtek W1700K2, Airoha AN7581/EN7581, 4x Arm Cortex-A53 at
>     1.4 GHz, 2 GiB RAM, airoha_eth wan (GDM2) netdev, 10Gb/s full-duplex,
>     MTU 9200, EIP93 crypto and IPsec packet engine present.
>   - Host: AMD Ryzen 9 9950X3D, 16 cores/32 threads, Open vSwitch,
>     MTU 9978, backed by a ConnectX-6 Dx 10Gb/s full-duplex link.
> 
> AP to host iperf3 result:
> 
>   AP offload      Sender          Receiver        Retransmits
>   on              918.2 Mbit/s    913.6 Mbit/s    0
>   off             782.4 Mbit/s    778.6 Mbit/s    3569
> 
> This is a 17.3% receiver-side throughput improvement for the AP TX ESP
> path in this setup, with retransmits eliminated in the offloaded run.
> 
> Jihong Min (3):
>   xfrm: extend ESP offload infrastructure for packet engines
>   crypto: inside-secure: add EIP93 ESP packet backend
>   net: airoha: add EIP93-backed ESP XFRM offload
> 
>  MAINTAINERS                                   |    1 +
>  drivers/crypto/inside-secure/eip93/Kconfig    |   10 +
>  drivers/crypto/inside-secure/eip93/Makefile   |    1 +
>  .../crypto/inside-secure/eip93/eip93-ipsec.c  | 1413 ++++++++++++++++
>  .../crypto/inside-secure/eip93/eip93-main.c   |   69 +-
>  .../crypto/inside-secure/eip93/eip93-main.h   |   38 +-
>  drivers/net/ethernet/airoha/Kconfig           |   11 +
>  drivers/net/ethernet/airoha/Makefile          |    1 +
>  drivers/net/ethernet/airoha/airoha_eth.c      |   51 +-
>  drivers/net/ethernet/airoha/airoha_eth.h      |   69 +
>  drivers/net/ethernet/airoha/airoha_xfrm.c     | 1474 +++++++++++++++++
>  include/crypto/eip93-ipsec.h                  |  132 ++
>  include/linux/netdevice.h                     |    3 +
>  include/net/xfrm.h                            |    8 +-
>  net/ipv4/esp4.c                               |    6 +-
>  net/ipv4/esp4_offload.c                       |   29 +-
>  net/ipv6/esp6.c                               |    6 +-
>  net/ipv6/esp6_offload.c                       |   29 +-
>  18 files changed, 3324 insertions(+), 27 deletions(-)
>  create mode 100644 drivers/crypto/inside-secure/eip93/eip93-ipsec.c
>  create mode 100644 drivers/net/ethernet/airoha/airoha_xfrm.c
>  create mode 100644 include/crypto/eip93-ipsec.h
> 

One note I should have included in the cover letter:

The hardware behavior used by this series was studied from the out-of-tree
IPsec branch of the mtk-eip93 driver:

  https://github.com/vschagen/mtk-eip93/tree/ipsec

That code was useful for understanding the EIP93 packet-mode ESP descriptor
programming and SA record values.

This series is not a direct import of that driver. The implementation was
rewritten around the current upstream driver layout and the Linux XFRM
netdev offload model, with EIP93 exposed as a packet-mode ESP backend used
by the Airoha netdev driver.

Sincerely,
Jihong Min