IB/mlx5: Set and get correct qp_num for a DCT QP

When a DCT QP is created on an active lag, it's dctc.port is assigned
in a round-robin way, which is from 1 to dev->lag_port. In this case
when querying this QP, we may get qp_attr.port_num > 2.
Fix this by setting qp->port when modifying a DCT QP, and read port_num
from qp->port instead of dctc.port when querying it.

Fixes: 7c4b1ab ("IB/mlx5: Add DCT RoCE LAG support")
Signed-off-by: Mark Zhang <[email protected]>
Reviewed-by: Maher Sanalla <[email protected]>
Link: https://patch.msgid.link/94c76bf0adbea997f87ffa27674e0a7118ad92a9.1737290358.git.leon@kernel.org
Signed-off-by: Leon Romanovsky <[email protected]>

Author: MarkZhang81

drivers/infiniband/hw/mlx5/qp.c

@@ -4579,6 +4579,8 @@ static int mlx5_ib_modify_dct(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 
 		set_id = mlx5_ib_get_counters_id(dev, attr->port_num - 1);
 		MLX5_SET(dctc, dctc, counter_set_id, set_id);
+
+		qp->port = attr->port_num;
 	} else if (cur_state == IB_QPS_INIT && new_state == IB_QPS_RTR) {
 		struct mlx5_ib_modify_qp_resp resp = {};
 		u32 out[MLX5_ST_SZ_DW(create_dct_out)] = {};
@@ -5074,7 +5076,7 @@ static int mlx5_ib_dct_query_qp(struct mlx5_ib_dev *dev, struct mlx5_ib_qp *mqp,
 	}
 
 	if (qp_attr_mask & IB_QP_PORT)
-		qp_attr->port_num = MLX5_GET(dctc, dctc, port);
+		qp_attr->port_num = mqp->port;
 	if (qp_attr_mask & IB_QP_MIN_RNR_TIMER)
 		qp_attr->min_rnr_timer = MLX5_GET(dctc, dctc, min_rnr_nak);
 	if (qp_attr_mask & IB_QP_AV) {