[dpdk-dev] [PATCH v3 2/2] ethdev: device configuration enhancement

[Wenzhuo Lu]

The new configuration is stored during the process.
But the process may fail. We better rolling the
configuration back as the new one doesn't take effect.

Signed-off-by: Wenzhuo Lu <wenzhuo.lu at intel.com>
---
 lib/librte_ethdev/rte_ethdev.c | 59 ++++++++++++++++++++++++++++++------------
 1 file changed, 43 insertions(+), 16 deletions(-)

diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
index f181c21..e2e7b04 100644
--- a/lib/librte_ethdev/rte_ethdev.c
+++ b/lib/librte_ethdev/rte_ethdev.c
@@ -1092,8 +1092,10 @@ struct rte_eth_dev *
 {
 	struct rte_eth_dev *dev;
 	struct rte_eth_dev_info dev_info;
+	struct rte_eth_conf orig_conf;
 	struct rte_eth_conf local_conf = *dev_conf;
 	int diag;
+	int ret;
 
 	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -EINVAL);
 
@@ -1106,12 +1108,16 @@ struct rte_eth_dev *
 		RTE_ETHDEV_LOG(ERR,
 			"Port %u must be stopped to allow configuration\n",
 			port_id);
-		return -EBUSY;
+		ret = -EBUSY;
+		goto fail;
 	}
 
 	/* Copy the dev_conf parameter into the dev structure,
 	 * then get the info.
+	 * But restore the original configure first, as rollback is needed
+	 * when failure happens.
 	 */
+	memcpy(&orig_conf, &dev->data->dev_conf, sizeof(dev->data->dev_conf));
 	memcpy(&dev->data->dev_conf, &local_conf, sizeof(dev->data->dev_conf));
 	rte_eth_dev_info_get(port_id, &dev_info);
 
@@ -1134,14 +1140,16 @@ struct rte_eth_dev *
 		RTE_ETHDEV_LOG(ERR,
 			"Number of RX queues requested (%u) is greater than max supported(%d)\n",
 			nb_rx_q, RTE_MAX_QUEUES_PER_PORT);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto rollback;
 	}
 
 	if (nb_tx_q > RTE_MAX_QUEUES_PER_PORT) {
 		RTE_ETHDEV_LOG(ERR,
 			"Number of TX queues requested (%u) is greater than max supported(%d)\n",
 			nb_tx_q, RTE_MAX_QUEUES_PER_PORT);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto rollback;
 	}
 
 	/*
@@ -1152,13 +1160,15 @@ struct rte_eth_dev *
 	if (nb_rx_q > dev_info.max_rx_queues) {
 		RTE_ETHDEV_LOG(ERR, "Ethdev port_id=%u nb_rx_queues=%u > %u\n",
 			port_id, nb_rx_q, dev_info.max_rx_queues);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto rollback;
 	}
 
 	if (nb_tx_q > dev_info.max_tx_queues) {
 		RTE_ETHDEV_LOG(ERR, "Ethdev port_id=%u nb_tx_queues=%u > %u\n",
 			port_id, nb_tx_q, dev_info.max_tx_queues);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto rollback;
 	}
 
 	/* Check that the device supports requested interrupts */
@@ -1166,13 +1176,15 @@ struct rte_eth_dev *
 			(!(dev->data->dev_flags & RTE_ETH_DEV_INTR_LSC))) {
 		RTE_ETHDEV_LOG(ERR, "Driver %s does not support lsc\n",
 			dev->device->driver->name);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto rollback;
 	}
 	if ((dev_conf->intr_conf.rmv == 1) &&
 			(!(dev->data->dev_flags & RTE_ETH_DEV_INTR_RMV))) {
 		RTE_ETHDEV_LOG(ERR, "Driver %s does not support rmv\n",
 			dev->device->driver->name);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto rollback;
 	}
 
 	/*
@@ -1185,13 +1197,15 @@ struct rte_eth_dev *
 				"Ethdev port_id=%u max_rx_pkt_len %u > max valid value %u\n",
 				port_id, dev_conf->rxmode.max_rx_pkt_len,
 				dev_info.max_rx_pktlen);
-			return -EINVAL;
+			ret = -EINVAL;
+			goto rollback;
 		} else if (dev_conf->rxmode.max_rx_pkt_len < ETHER_MIN_LEN) {
 			RTE_ETHDEV_LOG(ERR,
 				"Ethdev port_id=%u max_rx_pkt_len %u < min valid value %u\n",
 				port_id, dev_conf->rxmode.max_rx_pkt_len,
 				(unsigned)ETHER_MIN_LEN);
-			return -EINVAL;
+			ret = -EINVAL;
+			goto rollback;
 		}
 	} else {
 		if (dev_conf->rxmode.max_rx_pkt_len < ETHER_MIN_LEN ||
@@ -1210,7 +1224,8 @@ struct rte_eth_dev *
 			port_id, local_conf.rxmode.offloads,
 			dev_info.rx_offload_capa,
 			__func__);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto rollback;
 	}
 	if ((local_conf.txmode.offloads & dev_info.tx_offload_capa) !=
 	     local_conf.txmode.offloads) {
@@ -1220,7 +1235,8 @@ struct rte_eth_dev *
 			port_id, local_conf.txmode.offloads,
 			dev_info.tx_offload_capa,
 			__func__);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto rollback;
 	}
 
 	/* Check that device supports requested rss hash functions. */
@@ -1231,7 +1247,8 @@ struct rte_eth_dev *
 			"Ethdev port_id=%u invalid rss_hf: 0x%"PRIx64", valid value: 0x%"PRIx64"\n",
 			port_id, dev_conf->rx_adv_conf.rss_conf.rss_hf,
 			dev_info.flow_type_rss_offloads);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto rollback;
 	}
 
 	/*
@@ -1242,7 +1259,8 @@ struct rte_eth_dev *
 		RTE_ETHDEV_LOG(ERR,
 			"Port%u rte_eth_dev_rx_queue_config = %d\n",
 			port_id, diag);
-		return diag;
+		ret = diag;
+		goto rollback;
 	}
 
 	diag = rte_eth_dev_tx_queue_config(dev, nb_tx_q);
@@ -1251,7 +1269,8 @@ struct rte_eth_dev *
 			"Port%u rte_eth_dev_tx_queue_config = %d\n",
 			port_id, diag);
 		rte_eth_dev_rx_queue_config(dev, 0);
-		return diag;
+		ret = diag;
+		goto rollback;
 	}
 
 	diag = (*dev->dev_ops->dev_configure)(dev);
@@ -1260,7 +1279,8 @@ struct rte_eth_dev *
 			port_id, diag);
 		rte_eth_dev_rx_queue_config(dev, 0);
 		rte_eth_dev_tx_queue_config(dev, 0);
-		return eth_err(port_id, diag);
+		ret = eth_err(port_id, diag);
+		goto rollback;
 	}
 
 	/* Initialize Rx profiling if enabled at compilation time. */
@@ -1270,10 +1290,17 @@ struct rte_eth_dev *
 			port_id, diag);
 		rte_eth_dev_rx_queue_config(dev, 0);
 		rte_eth_dev_tx_queue_config(dev, 0);
-		return eth_err(port_id, diag);
+		ret = eth_err(port_id, diag);
+		goto rollback;
 	}
 
 	return 0;
+
+rollback:
+	memcpy(&dev->data->dev_conf, &orig_conf, sizeof(dev->data->dev_conf));
+
+fail:
+	return ret;
 }
 
 void
-- 
1.9.3