This is a note to let you know that I've just added the patch titled
net/mlx5e: Fix hw mtu initializing at XDP SQ allocation
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-mlx5e-fix-hw-mtu-initializing-at-xdp-sq-allocati.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit f89713bd7279018c47fd8b7f8901228ef25f15fc
Author: Adham Faris <afaris@xxxxxxxxxx>
Date: Wed Dec 14 16:02:57 2022 +0200
net/mlx5e: Fix hw mtu initializing at XDP SQ allocation
[ Upstream commit 1e267ab88dc44c48f556218f7b7f14c76f7aa066 ]
Current xdp xmit functions logic (mlx5e_xmit_xdp_frame_mpwqe or
mlx5e_xmit_xdp_frame), validates xdp packet length by comparing it to
hw mtu (configured at xdp sq allocation) before xmiting it. This check
does not account for ethernet fcs length (calculated and filled by the
nic). Hence, when we try sending packets with length > (hw-mtu -
ethernet-fcs-size), the device port drops it and tx_errors_phy is
incremented. Desired behavior is to catch these packets and drop them
by the driver.
Fix this behavior in XDP SQ allocation function (mlx5e_alloc_xdpsq) by
subtracting ethernet FCS header size (4 Bytes) from current hw mtu
value, since ethernet FCS is calculated and written to ethernet frames
by the nic.
Fixes: d8bec2b29a82 ("net/mlx5e: Support bpf_xdp_adjust_head()")
Signed-off-by: Adham Faris <afaris@xxxxxxxxxx>
Reviewed-by: Tariq Toukan <tariqt@xxxxxxxxxx>
Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 5e41dfdf79c8..951ede433813 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -1298,7 +1298,7 @@ static int mlx5e_alloc_xdpsq(struct mlx5e_channel *c,
sq->channel = c;
sq->uar_map = mdev->mlx5e_res.hw_objs.bfreg.map;
sq->min_inline_mode = params->tx_min_inline_mode;
- sq->hw_mtu = MLX5E_SW2HW_MTU(params, params->sw_mtu);
+ sq->hw_mtu = MLX5E_SW2HW_MTU(params, params->sw_mtu) - ETH_FCS_LEN;
sq->xsk_pool = xsk_pool;
sq->stats = sq->xsk_pool ?
