> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-boun...@osuosl.org> On Behalf Of
> Larysa Zaremba
> Sent: Thursday, April 18, 2024 3:29 PM
> To: Nguyen, Anthony L <anthony.l.ngu...@intel.com>;
> intel-wired-...@lists.osuosl.org; linux-ker...@vger.kernel.org;
> net...@vger.kernel.org
> Cc: Fijalkowski, Maciej <maciej.fijalkow...@intel.com>; Tantilov, Emil S
> <emil.s.tanti...@intel.com>; Zaremba, Larysa <larysa.zare...@intel.com>;
> Czapnik, Lukasz <lukasz.czap...@intel.com>; Eric Dumazet
> <eduma...@google.com>; Brady, Alan <alan.br...@intel.com>; Michal Swiatkowski
> <michal.swiatkow...@linux.intel.com>; Jakub Kicinski <k...@kernel.org>; Paolo
> Abeni <pab...@redhat.com>; David S. Miller <da...@davemloft.net>
> Subject: [Intel-wired-lan] [PATCH RESEND iwl-net] ice: Interpret
> .set_channels() input differently
>
> A bug occurs because a safety check guarding AF_XDP-related queues in
> ethnl_set_channels(), does not trigger. This happens, because kernel and ice
> driver interpret the ethtool command differently.
>
> How the bug occurs:
> 1. ethtool -l <IFNAME> -> combined: 40
> 2. Attach AF_XDP to queue 30
> 3. ethtool -L <IFNAME> rx 15 tx 15
> combined number is not specified, so command becomes {rx_count = 15,
> tx_count = 15, combined_count = 40}.
> 4. ethnl_set_channels checks, if there are any AF_XDP of queues from the
> new (combined_count + rx_count) to the old one, so from 55 to 40, check
> does not trigger.
> 5. ice interprets `rx 15 tx 15` as 15 combined channels and deletes the
> queue that AF_XDP is attached to.
>
> Interpret the command in a way that is more consistent with ethtool manual
> [0] (--show-channels and --set-channels).
>
> Considering that in the ice driver only the difference between RX and TX
> queues forms dedicated channels, change the correct way to set number of
> channels to:
>
> ethtool -L <IFNAME> combined 10 /* For symmetric queues */ ethtool -L
> <IFNAME> combined 8 tx 2 rx 0 /* For asymmetric queues */
>
> [0] https://man7.org/linux/man-pages/man8/ethtool.8.html
>
> Fixes: 87324e747fde ("ice: Implement ethtool ops for channels")
> Reviewed-by: Michal Swiatkowski <michal.swiatkow...@linux.intel.com>
> Signed-off-by: Larysa Zaremba <larysa.zare...@intel.com>
> ---
> drivers/net/ethernet/intel/ice/ice_ethtool.c | 22 ++++++--------------
> 1 file changed, 6 insertions(+), 16 deletions(-)
>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pu...@intel.com> (A
Contingent worker at Intel)
