[dpdk-dev] [PATCH] ethdev: limit maximum number of queues

[Thomas Monjalon <thomas@monjalon.net>]

A buffer overflow happens in testpmd with some drivers
since the queue arrays are limited to RTE_MAX_QUEUES_PER_PORT.

The advertised capabilities of mlx4, mlx5 and softnic
for the number of queues were the maximum number: UINT16_MAX.
They must be limited by the configured RTE_MAX_QUEUES_PER_PORT
that applications expect to be respected.

The limitation is applied in above drivers having no limitation,
and at ethdev level (function rte_eth_dev_info_get), in order
to force the configured limit for all drivers.

Fixes: 7fae69eeff13 ("mlx4: new poll mode driver")
Fixes: e60fbd5b24fc ("mlx5: add device configure/start/stop")
Fixes: cc6d421574fe ("net/softnic: add softnic PMD")
Fixes: 9e6b36c34ce9 ("app/testpmd: reduce memory consumption")
Cc: stable@dpdk.org

Reported-by: Raslan Darawsheh <rasland@mellanox.com>
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
---
 drivers/net/mlx4/mlx4_ethdev.c        | 4 +---
 drivers/net/mlx5/mlx5_ethdev.c        | 4 +---
 drivers/net/softnic/rte_eth_softnic.c | 4 ++--
 lib/librte_ethdev/rte_ethdev.c        | 6 ++++++
 4 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/net/mlx4/mlx4_ethdev.c b/drivers/net/mlx4/mlx4_ethdev.c
index dfb24c22d0..a18a66cb4a 100644
--- a/drivers/net/mlx4/mlx4_ethdev.c
+++ b/drivers/net/mlx4/mlx4_ethdev.c
@@ -646,9 +646,7 @@ mlx4_dev_infos_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *info)
 	 */
 	max = ((priv->device_attr.max_cq > priv->device_attr.max_qp) ?
 	       priv->device_attr.max_qp : priv->device_attr.max_cq);
-	/* If max >= 65535 then max = 0, max_rx_queues is uint16_t. */
-	if (max >= 65535)
-		max = 65535;
+	max = RTE_MIN(max, (unsigned int)RTE_MAX_QUEUES_PER_PORT);
 	info->max_rx_queues = max;
 	info->max_tx_queues = max;
 	info->max_mac_addrs = RTE_DIM(priv->mac);
diff --git a/drivers/net/mlx5/mlx5_ethdev.c b/drivers/net/mlx5/mlx5_ethdev.c
index d80ae458bc..045dae6b5a 100644
--- a/drivers/net/mlx5/mlx5_ethdev.c
+++ b/drivers/net/mlx5/mlx5_ethdev.c
@@ -617,9 +617,7 @@ mlx5_dev_infos_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *info)
 	 */
 	max = RTE_MIN(priv->sh->device_attr.orig_attr.max_cq,
 		      priv->sh->device_attr.orig_attr.max_qp);
-	/* If max >= 65535 then max = 0, max_rx_queues is uint16_t. */
-	if (max >= 65535)
-		max = 65535;
+	max = RTE_MIN(max, (unsigned int)RTE_MAX_QUEUES_PER_PORT);
 	info->max_rx_queues = max;
 	info->max_tx_queues = max;
 	info->max_mac_addrs = MLX5_MAX_UC_MAC_ADDRESSES;
diff --git a/drivers/net/softnic/rte_eth_softnic.c b/drivers/net/softnic/rte_eth_softnic.c
index 11723778fd..1065cbf847 100644
--- a/drivers/net/softnic/rte_eth_softnic.c
+++ b/drivers/net/softnic/rte_eth_softnic.c
@@ -91,8 +91,8 @@ pmd_dev_infos_get(struct rte_eth_dev *dev __rte_unused,
 	struct rte_eth_dev_info *dev_info)
 {
 	dev_info->max_rx_pktlen = UINT32_MAX;
-	dev_info->max_rx_queues = UINT16_MAX;
-	dev_info->max_tx_queues = UINT16_MAX;
+	dev_info->max_rx_queues = RTE_MAX_QUEUES_PER_PORT;
+	dev_info->max_tx_queues = RTE_MAX_QUEUES_PER_PORT;
 
 	return 0;
 }
diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
index 8d2ce31a81..6e9cb243ea 100644
--- a/lib/librte_ethdev/rte_ethdev.c
+++ b/lib/librte_ethdev/rte_ethdev.c
@@ -2986,6 +2986,12 @@ rte_eth_dev_info_get(uint16_t port_id, struct rte_eth_dev_info *dev_info)
 		return eth_err(port_id, diag);
 	}
 
+	/* Maximum number of queues should be <= RTE_MAX_QUEUES_PER_PORT */
+	dev_info->max_rx_queues = RTE_MIN(dev_info->max_rx_queues,
+			RTE_MAX_QUEUES_PER_PORT);
+	dev_info->max_tx_queues = RTE_MIN(dev_info->max_tx_queues,
+			RTE_MAX_QUEUES_PER_PORT);
+
 	dev_info->driver_name = dev->device->driver->name;
 	dev_info->nb_rx_queues = dev->data->nb_rx_queues;
 	dev_info->nb_tx_queues = dev->data->nb_tx_queues;
-- 
2.23.0