[dpdk-dev] [PATCH 2/5] net/tap: fix multi-queue support

[Keith Wiles <keith.wiles@intel.com>]

Signed-off-by: Keith Wiles <keith.wiles@intel.com>
---
 drivers/net/tap/rte_eth_tap.c | 93 ++++++++++++++++++++++---------------------
 1 file changed, 48 insertions(+), 45 deletions(-)

diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
index 3f179c3..9ed7a87 100644
--- a/drivers/net/tap/rte_eth_tap.c
+++ b/drivers/net/tap/rte_eth_tap.c
@@ -115,10 +115,9 @@ struct pmd_internals {
  * supplied name.
  */
 static int
-tun_alloc(char *name)
+tun_alloc(char *name, uint16_t qid)
 {
 	struct ifreq ifr;
-	unsigned int features;
 	int fd;
 
 	memset(&ifr, 0, sizeof(struct ifreq));
@@ -133,55 +132,57 @@ tun_alloc(char *name)
 		goto error;
 	}
 
-	/* Grab the TUN features to verify we can work */
-	if (ioctl(fd, TUNGETFEATURES, &features) < 0) {
-		RTE_LOG(ERR, PMD, "Unable to get TUN/TAP features\n");
-		goto error;
-	}
-	RTE_LOG(DEBUG, PMD, "TUN/TAP Features %08x\n", features);
+	/* This can only be done once per interface */
+	if (qid == 0) {
+		unsigned int features;
+
+		/* Grab the TUN features to verify we can work */
+		if (ioctl(fd, TUNGETFEATURES, &features) < 0) {
+			RTE_LOG(ERR, PMD, "Unable to get TUN/TAP features\n");
+			goto error;
+		}
+		RTE_LOG(DEBUG, PMD, "TUN/TAP Features %08x\n", features);
 
 #ifdef IFF_MULTI_QUEUE
-	if (!(features & IFF_MULTI_QUEUE) && (RTE_PMD_TAP_MAX_QUEUES > 1)) {
-		RTE_LOG(DEBUG, PMD, "TUN/TAP device only one queue\n");
-		goto error;
-	} else if ((features & IFF_ONE_QUEUE) &&
-			(RTE_PMD_TAP_MAX_QUEUES == 1)) {
-		ifr.ifr_flags |= IFF_ONE_QUEUE;
-		RTE_LOG(DEBUG, PMD, "Single queue only support\n");
-	} else {
-		ifr.ifr_flags |= IFF_MULTI_QUEUE;
-		RTE_LOG(DEBUG, PMD, "Multi-queue support for %d queues\n",
-			RTE_PMD_TAP_MAX_QUEUES);
-	}
+		if (!(features & IFF_MULTI_QUEUE) && (RTE_PMD_TAP_MAX_QUEUES > 1)) {
+			RTE_LOG(DEBUG, PMD, "TUN/TAP device only one queue\n");
+			goto error;
+		} else if ((features & IFF_ONE_QUEUE) &&
+				(RTE_PMD_TAP_MAX_QUEUES == 1)) {
+			ifr.ifr_flags |= IFF_ONE_QUEUE;
+			RTE_LOG(DEBUG, PMD, "Single queue only support\n");
+		} else {
+			ifr.ifr_flags |= IFF_MULTI_QUEUE;
+			RTE_LOG(DEBUG, PMD, "Multi-queue support for %d queues\n",
+				RTE_PMD_TAP_MAX_QUEUES);
+		}
 #else
-	if (RTE_PMD_TAP_MAX_QUEUES > 1) {
-		RTE_LOG(DEBUG, PMD, "TUN/TAP device only one queue\n");
-		goto error;
-	} else {
-		ifr.ifr_flags |= IFF_ONE_QUEUE;
-		RTE_LOG(DEBUG, PMD, "Single queue only support\n");
-	}
+		if (RTE_PMD_TAP_MAX_QUEUES > 1) {
+			RTE_LOG(DEBUG, PMD, "TUN/TAP device only one queue\n");
+			goto error;
+		} else {
+			ifr.ifr_flags |= IFF_ONE_QUEUE;
+			RTE_LOG(DEBUG, PMD, "Single queue only support\n");
+		}
 #endif
 
-	/* Set the TUN/TAP configuration and get the name if needed */
-	if (ioctl(fd, TUNSETIFF, (void *)&ifr) < 0) {
-		RTE_LOG(ERR, PMD, "Unable to set TUNSETIFF for %s\n",
-			ifr.ifr_name);
-		perror("TUNSETIFF");
-		goto error;
-	}
+		/* Set the TUN/TAP configuration and get the name if needed */
+		if (ioctl(fd, TUNSETIFF, (void *)&ifr) < 0) {
+			RTE_LOG(ERR, PMD, "Unable to set TUNSETIFF for %s\n",
+				ifr.ifr_name);
+			perror("TUNSETIFF");
+			goto error;
+		}
 
-	/* Always set the file descriptor to non-blocking */
-	if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0) {
-		RTE_LOG(ERR, PMD, "Unable to set to nonblocking\n");
-		perror("F_SETFL, NONBLOCK");
-		goto error;
+		/* Always set the file descriptor to non-blocking */
+		if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0) {
+			RTE_LOG(WARNING, PMD, "Unable to set %s to nonblocking\n",
+				ifr.ifr_name);
+			perror("F_SETFL, NONBLOCK");
+			goto error;
+		}
 	}
 
-	/* If the name is different that new name as default */
-	if (name && strcmp(name, ifr.ifr_name))
-		snprintf(name, RTE_ETH_NAME_MAX_LEN - 1, "%s", ifr.ifr_name);
-
 	return fd;
 
 error:
@@ -512,7 +513,7 @@ tap_setup_queue(struct rte_eth_dev *dev,
 		if (fd < 0) {
 			RTE_LOG(INFO, PMD, "Add queue to TAP %s for qid %d\n",
 				pmd->name, qid);
-			fd = tun_alloc(pmd->name);
+			fd = tun_alloc(pmd->name, qid);
 			if (fd < 0) {
 				RTE_LOG(ERR, PMD, "tun_alloc(%s) failed\n", pmd->name);
 				return -1;
@@ -711,7 +712,7 @@ eth_dev_tap_create(const char *name, char *tap_name)
 	snprintf(dev->data->name, sizeof(dev->data->name), "%s", name);
 
 	/* Create the first Tap device */
-	fd = tun_alloc(tap_name);
+	fd = tun_alloc(tap_name, 0);
 	if (fd < 0) {
 		RTE_LOG(ERR, PMD, "tun_alloc() failed\n");
 		goto error_exit;
@@ -739,6 +740,8 @@ eth_dev_tap_create(const char *name, char *tap_name)
 error_exit:
 	RTE_PMD_DEBUG_TRACE("Unable to initialize %s\n", name);
 
+	if (fd > 0)
+		close(fd);
 	rte_free(data);
 	rte_free(pmd);
 
-- 
2.8.0.GIT