From: Yongseok Koh <yskoh@mellanox.com>
Date: Wed, 1 May 2019 01:01:43 +0000 (-0700)
Subject: net/mlx5: check Tx queue size overflow
X-Git-Url: http://git.droids-corp.org/?p=dpdk.git;a=commitdiff_plain;h=f6d9ab4e769f0f95ecac1b418106e9f8137ca60c

net/mlx5: check Tx queue size overflow

If Tx packet inlining is enabled, rdma-core library should allocate large
Tx WQ enough to support it. It is better for PMD to calculate the size of
WQ based on the parameters and return error with appropriate message if it
exceeds the device capability.

Cc: stable@dpdk.org

Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
Acked-by: Shahaf Shuler <shahafs@mellanox.com>
---

diff --git a/drivers/net/mlx5/mlx5_txq.c b/drivers/net/mlx5/mlx5_txq.c
index 4d55fd413c..b281c45027 100644
--- a/drivers/net/mlx5/mlx5_txq.c
+++ b/drivers/net/mlx5/mlx5_txq.c
@@ -678,6 +678,27 @@ mlx5_txq_ibv_verify(struct rte_eth_dev *dev)
 	return ret;
 }
 
+/**
+ * Calcuate the total number of WQEBB for Tx queue.
+ *
+ * Simplified version of calc_sq_size() in rdma-core.
+ *
+ * @param txq_ctrl
+ *   Pointer to Tx queue control structure.
+ *
+ * @return
+ *   The number of WQEBB.
+ */
+static int
+txq_calc_wqebb_cnt(struct mlx5_txq_ctrl *txq_ctrl)
+{
+	unsigned int wqe_size;
+	const unsigned int desc = 1 << txq_ctrl->txq.elts_n;
+
+	wqe_size = MLX5_WQE_SIZE + txq_ctrl->max_inline_data;
+	return rte_align32pow2(wqe_size * desc) / MLX5_WQE_SIZE;
+}
+
 /**
  * Set Tx queue parameters from device configuration.
  *
@@ -824,10 +845,16 @@ mlx5_txq_new(struct rte_eth_dev *dev, uint16_t idx, uint16_t desc,
 	tmpl->txq.port_id = dev->data->port_id;
 	tmpl->txq.idx = idx;
 	txq_set_params(tmpl);
-	DRV_LOG(DEBUG, "port %u device_attr.max_qp_wr is %d",
-		dev->data->port_id, priv->sh->device_attr.orig_attr.max_qp_wr);
-	DRV_LOG(DEBUG, "port %u device_attr.max_sge is %d",
-		dev->data->port_id, priv->sh->device_attr.orig_attr.max_sge);
+	if (txq_calc_wqebb_cnt(tmpl) >
+	    priv->sh->device_attr.orig_attr.max_qp_wr) {
+		DRV_LOG(ERR,
+			"port %u Tx WQEBB count (%d) exceeds the limit (%d),"
+			" try smaller queue size",
+			dev->data->port_id, txq_calc_wqebb_cnt(tmpl),
+			priv->sh->device_attr.orig_attr.max_qp_wr);
+		rte_errno = ENOMEM;
+		goto error;
+	}
 	tmpl->txq.elts =
 		(struct rte_mbuf *(*)[1 << tmpl->txq.elts_n])(tmpl + 1);
 	rte_atomic32_inc(&tmpl->refcnt);