[dpdk-dev] [PATCH] ethdev: ensure consistent port id assignment

["Tootoonchian, Amin" <amin.tootoonchian@intel.com>]

The rte_eth_dev_allocate() code has an implicit assumption that the port
id assignment in the secondary process is consistent with that of the
primary. The current code breaks if the enumeration of ethdevs in
primary and secondary processes are not identical (e.g., when the
black/whitelist and vdev args of the primary and secondary do not match,
or when the primary dynamically adds/removes ethdevs).

To fix this problem, rte_eth_dev_allocate() now looks up port id by name
in a secondary process (making it explicit that ethdevs can only be
created and initialized by the primary process). Upon releasing a port,
the primary process zeros out eth_dev->data to avoid false positives in
port id lookup by rte_eth_dev_get_port_by_name().

Signed-off-by: Amin Tootoonchian <amin.tootoonchian@intel.com>
---
 lib/librte_ether/rte_ethdev.c | 44 +++++++++++++++++++++++++++++--------------
 1 file changed, 30 insertions(+), 14 deletions(-)

diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
index 0a6e3f1..1801f57 100644
--- a/lib/librte_ether/rte_ethdev.c
+++ b/lib/librte_ether/rte_ethdev.c
@@ -195,25 +195,37 @@ rte_eth_dev_allocate(const char *name, enum rte_eth_dev_type type)
 	uint8_t port_id;
 	struct rte_eth_dev *eth_dev;
 
-	port_id = rte_eth_dev_find_free_port();
-	if (port_id == RTE_MAX_ETHPORTS) {
-		RTE_PMD_DEBUG_TRACE("Reached maximum number of Ethernet ports\n");
-		return NULL;
-	}
-
 	if (rte_eth_dev_data == NULL)
 		rte_eth_dev_data_alloc();
 
-	if (rte_eth_dev_allocated(name) != NULL) {
-		RTE_PMD_DEBUG_TRACE("Ethernet Device with name %s already allocated!\n",
-				name);
-		return NULL;
+	if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
+		port_id = rte_eth_dev_find_free_port();
+		if (port_id == RTE_MAX_ETHPORTS) {
+			RTE_PMD_DEBUG_TRACE("Reached maximum number of Ethernet ports\n");
+			return NULL;
+		}
+
+		if (rte_eth_dev_allocated(name) != NULL) {
+			RTE_PMD_DEBUG_TRACE("Ethernet Device with name %s already allocated!\n",
+					name);
+			return NULL;
+		}
+	} else {
+		if (rte_eth_dev_get_port_by_name(name, &port_id) != 0) {
+			RTE_PMD_DEBUG_TRACE("Ethernet Device with name %s could not be found!\n",
+					name);
+			return NULL;
+		}
 	}
 
 	eth_dev = &rte_eth_devices[port_id];
 	eth_dev->data = &rte_eth_dev_data[port_id];
-	snprintf(eth_dev->data->name, sizeof(eth_dev->data->name), "%s", name);
-	eth_dev->data->port_id = port_id;
+
+	if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
+		snprintf(eth_dev->data->name, sizeof(eth_dev->data->name), "%s", name);
+		eth_dev->data->port_id = port_id;
+	}
+
 	eth_dev->attached = DEV_ATTACHED;
 	eth_dev->dev_type = type;
 	nb_ports++;
@@ -293,8 +305,10 @@ rte_eth_dev_init(struct rte_pci_driver *pci_drv,
 			pci_drv->name,
 			(unsigned) pci_dev->id.vendor_id,
 			(unsigned) pci_dev->id.device_id);
-	if (rte_eal_process_type() == RTE_PROC_PRIMARY)
+	if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
 		rte_free(eth_dev->data->dev_private);
+		memset(eth_dev->data, 0, sizeof(*rte_eth_dev_data));
+	}
 	rte_eth_dev_release_port(eth_dev);
 	return diag;
 }
@@ -330,8 +344,10 @@ rte_eth_dev_uninit(struct rte_pci_device *pci_dev)
 	/* free ether device */
 	rte_eth_dev_release_port(eth_dev);
 
-	if (rte_eal_process_type() == RTE_PROC_PRIMARY)
+	if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
 		rte_free(eth_dev->data->dev_private);
+		memset(eth_dev->data, 0, sizeof(*rte_eth_dev_data));
+	}
 
 	eth_dev->pci_dev = NULL;
 	eth_dev->driver = NULL;
-- 
2.8.1