net/mlx5e: Enable remove flow for hard packet limit

In the commit a2a73ea1 ("net/mlx5e: Don't listen to remove flows
event"), remove_flow_enable event is removed, and the hard limit
usually relies on software mechanism added in commit b2f7b01d
("net/mlx5e: Simulate missing IPsec TX limits hardware
functionality"). But the delayed work is rescheduled every one second,
which is slow for fast traffic. As a result, traffic can't be blocked
even reaches the hard limit, which usually happens when soft and hard
limits are very close.

In reality it won't happen because soft limit is much lower than hard
limit. But, as an optimization for RX to block traffic when reaching
hard limit, need to set remove_flow_enable. When remove flow is
enabled, IPSEC HARD_LIFETIME ASO syndrome will be set in the metadata
defined in the ASO return register if packets reach hard lifetime
threshold. And those packets are dropped immediately by the steering
table.
Signed-off-by: Jianbo Liu <jianbol@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20240808055927.2059700-3-tariqt@nvidia.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_offload.c

@@ -127,6 +127,7 @@ static void mlx5e_ipsec_packet_setup(void *obj, u32 pdn,
 		MLX5_SET(ipsec_aso, aso_ctx, remove_flow_pkt_cnt,
 			 attrs->lft.hard_packet_limit);
 		MLX5_SET(ipsec_aso, aso_ctx, hard_lft_arm, 1);
+		MLX5_SET(ipsec_aso, aso_ctx, remove_flow_enable, 1);
 	}
 
 	if (attrs->lft.soft_packet_limit != XFRM_INF) {