[dpdk-dev] [PATCH] ethdev: fix port ID retrieval on vdev attach

[Andrew Rybchenko <arybchenko@solarflare.com>]

From: Ivan Malov <ivan.malov@oktetlabs.ru>

Attaching a vdev port may result in multiple
ports actually added because a vdev port may
have slave devices to be attached implicitly.

Ethdev attach API has to fill in the port ID
to be read back by the user and what it does
is take the last assigned ID from the common
list after attach completion. Such an ID may
belong to a slave device and not to the vdev.

This mistake must be precluded by requesting
the port ID by name of device being attached.

Fixes: b0fb26685570 ("ethdev: convert to EAL hotplug")
Cc: David Marchand <david.marchand@6wind.com>
Cc: stable@dpdk.org

Reported-by: Andrew Rybchenko <arybchenko@solarflare.com>
Signed-off-by: Ivan Malov <ivan.malov@oktetlabs.ru>
Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
---
 lib/librte_ethdev/rte_ethdev.c | 26 ++++----------------------
 1 file changed, 4 insertions(+), 22 deletions(-)

diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
index 16b8258a7..dbb9244ec 100644
--- a/lib/librte_ethdev/rte_ethdev.c
+++ b/lib/librte_ethdev/rte_ethdev.c
@@ -46,7 +46,6 @@ int rte_eth_dev_logtype;
 
 static const char *MZ_RTE_ETH_DEV_DATA = "rte_eth_dev_data";
 struct rte_eth_dev rte_eth_devices[RTE_MAX_ETHPORTS];
-static uint16_t eth_dev_last_created_port;
 
 /* spinlock for eth device callbacks */
 static rte_spinlock_t rte_eth_dev_cb_lock = RTE_SPINLOCK_INITIALIZER;
@@ -284,8 +283,6 @@ eth_dev_get(uint16_t port_id)
 
 	eth_dev->data = &rte_eth_dev_shared_data->data[port_id];
 
-	eth_dev_last_created_port = port_id;
-
 	return eth_dev;
 }
 
@@ -646,7 +643,6 @@ eth_err(uint16_t port_id, int ret)
 int
 rte_eth_dev_attach(const char *devargs, uint16_t *port_id)
 {
-	int current = rte_eth_dev_count_total();
 	struct rte_devargs da;
 	int ret = -1;
 
@@ -665,24 +661,10 @@ rte_eth_dev_attach(const char *devargs, uint16_t *port_id)
 	if (ret < 0)
 		goto err;
 
-	/* no point looking at the port count if no port exists */
-	if (!rte_eth_dev_count_total()) {
-		RTE_ETHDEV_LOG(ERR, "No port found for device (%s)\n", da.name);
-		ret = -1;
-		goto err;
-	}
-
-	/* if nothing happened, there is a bug here, since some driver told us
-	 * it did attach a device, but did not create a port.
-	 * FIXME: race condition in case of plug-out of another device
-	 */
-	if (current == rte_eth_dev_count_total()) {
-		ret = -1;
-		goto err;
-	}
-
-	*port_id = eth_dev_last_created_port;
-	ret = 0;
+	ret = rte_eth_dev_get_port_by_name(da.name, port_id);
+	if (ret != 0)
+		RTE_ETHDEV_LOG(ERR, "No port found for device (%s)\n",
+			       da.name);
 
 err:
 	free(da.args);
-- 
2.17.1