Re: [PATCH iwl-next v2 0/5] ice: add support for devmem/io_uring Rx and Tx

[Alexander Lobakin]

From: Alexander Lobakin <aleksander.lobakin@xxxxxxxxx>
Date: Thu, 4 Dec 2025 16:51:28 +0100

> Now that ice uses libeth for managing Rx buffers and supports
> configurable header split, it's ready to get support for sending
> and receiving packets with unreadable (to the kernel) frags.
> 
> Extend libeth just a little bit to allow creating PPs with custom
> memory providers and make sure ice works correctly with the netdev
> ops locking. Then add the full set of queue_mgmt_ops and don't
> unmap unreadable frags on Tx completion.
> No perf regressions for the regular flows and no code duplication
> implied.
> 
> Credits to the fbnic developers, which's code helped me understand
> the memory providers and queue_mgmt_ops logics and served as
> a reference.
> 
> Alexander Lobakin (5):
>   libeth: pass Rx queue index to PP when creating a fill queue
>   libeth: handle creating pools with unreadable buffers
>   ice: migrate to netdev ops lock
>   ice: implement Rx queue management ops
>   ice: add support for transmitting unreadable frags
> 
>  drivers/net/ethernet/intel/ice/ice_lib.h    |  11 +-
>  drivers/net/ethernet/intel/ice/ice_txrx.h   |   2 +
>  drivers/net/ethernet/intel/idpf/idpf_txrx.h |   2 +
>  include/net/libeth/rx.h                     |   2 +
>  include/net/libeth/tx.h                     |   2 +-
>  drivers/net/ethernet/intel/iavf/iavf_txrx.c |   1 +
>  drivers/net/ethernet/intel/ice/ice_base.c   | 194 ++++++++++++++------
>  drivers/net/ethernet/intel/ice/ice_lib.c    |  56 +++++-
>  drivers/net/ethernet/intel/ice/ice_main.c   |  50 ++---
>  drivers/net/ethernet/intel/ice/ice_sf_eth.c |   2 +
>  drivers/net/ethernet/intel/ice/ice_txrx.c   |  43 +++--
>  drivers/net/ethernet/intel/ice/ice_xsk.c    |   4 +-
>  drivers/net/ethernet/intel/idpf/idpf_txrx.c |  13 ++
>  drivers/net/ethernet/intel/libeth/rx.c      |  46 +++++
>  14 files changed, 325 insertions(+), 103 deletions(-)
> 
> ---
> From v1[0]:
> * rebase on top of the latest next-queue;
> * fix a typo 'rxq_ixd' -> 'rxq_idx' (Tony).
> 
> Testing hints:
> * regular Rx and Tx for regressions;
> * <kernel root>/tools/testing/selftests/drivers/net/hw/ contains
>   scripts for testing netmem Rx and Tx, namely devmem.py and
>   iou-zcrx.py (read the documentation first).
> 
> [0] https://lore.kernel.org/intel-wired-lan/20251125173603.3834486-1-aleksander.lobakin@xxxxxxxxx

Current status from the validation:

* io_uring tests pass, except for tests which try to setup RSS Rx
  contexts -- after recent changes in the kernel, seems like at least
  some of our drivers return -EOPNOTSUPP when trying to configure RSS.

Tony, did you have any related reports or planned fixes?

* devmem -- only the Tx test fails, may be related to our complicated
  .ndo_start_xmit() logic in ice, I'll investigate this as soon as
  I get some details from the val.

Thanks,
Olek