[dpdk-dev] [PATCH v4 1/3] ethdev: fix invalid device configuration after failure

[Ferruh Yigit <ferruh.yigit@intel.com>]

From: Wenzhuo Lu <wenzhuo.lu@intel.com>

The new configuration is stored during the rte_eth_dev_configure() API
but the API may fail. After failure stored configuration will be
invalid since it is not fully applied to the device.

We better roll the configuration back after failure.

Fixes: af75078fece3 ("first public release")
Cc: stable@dpdk.org

Signed-off-by: Wenzhuo Lu <wenzhuo.lu@intel.com>
Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
---
Cc: Andrew Rybchenko <arybchenko@solarflare.com>
---
 lib/librte_ethdev/rte_ethdev.c | 49 +++++++++++++++++++++++++---------
 1 file changed, 36 insertions(+), 13 deletions(-)

diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
index 8eaa5fcc7..04dff1f5e 100644
--- a/lib/librte_ethdev/rte_ethdev.c
+++ b/lib/librte_ethdev/rte_ethdev.c
@@ -1092,8 +1092,10 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
 {
 	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);
 
@@ -1140,6 +1142,9 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
 		return -EBUSY;
 	}
 
+	 /* Store original config, as rollback required on failure */
+	memcpy(&orig_conf, &dev->data->dev_conf, sizeof(dev->data->dev_conf));
+
 	/* Copy the dev_conf parameter into the dev structure */
 	memcpy(&dev->data->dev_conf, &local_conf, sizeof(dev->data->dev_conf));
 
@@ -1151,13 +1156,15 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
 	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 */
@@ -1165,13 +1172,15 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
 			(!(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;
 	}
 
 	/*
@@ -1184,13 +1193,15 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
 				"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 ||
@@ -1209,7 +1220,8 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
 			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) {
@@ -1219,7 +1231,8 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
 			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. */
@@ -1230,7 +1243,8 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
 			"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;
 	}
 
 	/*
@@ -1241,7 +1255,8 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
 		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);
@@ -1250,7 +1265,8 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
 			"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);
@@ -1259,7 +1275,8 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
 			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. */
@@ -1269,10 +1286,16 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
 			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));
+
+	return ret;
 }
 
 void
-- 
2.17.2