[dpdk-dev] [PATCH] net/virtio-user: support changing tap interface name

[Wenfeng Liu <liuwf@arraynetworks.com.cn>]

This patch adds a new option 'iface' to change the interface name of
tap device with vhost-kernel as backend.

Signed-off-by: Wenfeng Liu <liuwf@arraynetworks.com.cn>
---
 drivers/net/virtio/virtio_user/virtio_user_dev.c | 12 ++++++++----
 drivers/net/virtio/virtio_user/virtio_user_dev.h |  2 +-
 drivers/net/virtio/virtio_user_ethdev.c          | 24 +++++++++++++++++++++---
 3 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
index 21ed00d..e7fd65f 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
@@ -193,9 +193,6 @@ int virtio_user_stop_device(struct virtio_user_dev *dev)
 	for (i = 0; i < dev->max_queue_pairs; ++i)
 		dev->ops->enable_qp(dev, i, 0);
 
-	free(dev->ifname);
-	dev->ifname = NULL;
-
 	return 0;
 }
 
@@ -268,7 +265,7 @@ int virtio_user_stop_device(struct virtio_user_dev *dev)
 
 int
 virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
-		     int cq, int queue_size, const char *mac)
+		     int cq, int queue_size, const char *mac, char **ifname)
 {
 	snprintf(dev->path, PATH_MAX, "%s", path);
 	dev->max_queue_pairs = queues;
@@ -277,6 +274,11 @@ int virtio_user_stop_device(struct virtio_user_dev *dev)
 	dev->mac_specified = 0;
 	parse_mac(dev, mac);
 
+	if (*ifname) {
+		dev->ifname = *ifname;
+		*ifname = NULL;
+	}
+
 	if (virtio_user_dev_setup(dev) < 0) {
 		PMD_INIT_LOG(ERR, "backend set up fails");
 		return -1;
@@ -327,6 +329,8 @@ int virtio_user_stop_device(struct virtio_user_dev *dev)
 		free(dev->vhostfds);
 		free(dev->tapfds);
 	}
+
+	free(dev->ifname);
 }
 
 static uint8_t
diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.h b/drivers/net/virtio/virtio_user/virtio_user_dev.h
index 0d39f40..6ecb91e 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.h
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.h
@@ -69,7 +69,7 @@ struct virtio_user_dev {
 int virtio_user_start_device(struct virtio_user_dev *dev);
 int virtio_user_stop_device(struct virtio_user_dev *dev);
 int virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
-			 int cq, int queue_size, const char *mac);
+			 int cq, int queue_size, const char *mac, char **ifname);
 void virtio_user_dev_uninit(struct virtio_user_dev *dev);
 void virtio_user_handle_cq(struct virtio_user_dev *dev, uint16_t queue_idx);
 #endif
diff --git a/drivers/net/virtio/virtio_user_ethdev.c b/drivers/net/virtio/virtio_user_ethdev.c
index 0b226ac..16d1526 100644
--- a/drivers/net/virtio/virtio_user_ethdev.c
+++ b/drivers/net/virtio/virtio_user_ethdev.c
@@ -243,6 +243,8 @@
 	VIRTIO_USER_ARG_PATH,
 #define VIRTIO_USER_ARG_QUEUE_SIZE     "queue_size"
 	VIRTIO_USER_ARG_QUEUE_SIZE,
+#define VIRTIO_USER_ARG_INTERFACE_NAME "iface"
+	VIRTIO_USER_ARG_INTERFACE_NAME,
 	NULL
 };
 
@@ -259,6 +261,9 @@
 
 	*(char **)extra_args = strdup(value);
 
+	if (!*(char **)extra_args)
+		return -ENOMEM;
+
 	return 0;
 }
 
@@ -347,6 +352,7 @@
 	uint64_t cq = VIRTIO_USER_DEF_CQ_EN;
 	uint64_t queue_size = VIRTIO_USER_DEF_Q_SZ;
 	char *path = NULL;
+	char *ifname = NULL;
 	char *mac_addr = NULL;
 	int ret = -1;
 
@@ -375,6 +381,15 @@
 		goto end;
 	}
 
+	if (rte_kvargs_count(kvlist, VIRTIO_USER_ARG_INTERFACE_NAME) == 1) {
+		if (rte_kvargs_process(kvlist, VIRTIO_USER_ARG_INTERFACE_NAME,
+				       &get_string_arg, &ifname) < 0) {
+			PMD_INIT_LOG(ERR, "error to parse %s",
+				     VIRTIO_USER_ARG_INTERFACE_NAME);
+			goto end;
+		}
+	}
+
 	if (rte_kvargs_count(kvlist, VIRTIO_USER_ARG_MAC) == 1) {
 		if (rte_kvargs_process(kvlist, VIRTIO_USER_ARG_MAC,
 				       &get_string_arg, &mac_addr) < 0) {
@@ -413,7 +428,7 @@
 		cq = 1;
 	}
 
-	if (queues > 1 && cq == 0) {
+	if (queues > 1 && cq == VIRTIO_USER_DEF_CQ_EN) {
 		PMD_INIT_LOG(ERR, "multi-q requires ctrl-q");
 		goto end;
 	}
@@ -426,7 +441,7 @@
 
 	hw = eth_dev->data->dev_private;
 	if (virtio_user_dev_init(hw->virtio_user_dev, path, queues, cq,
-				 queue_size, mac_addr) < 0) {
+				 queue_size, mac_addr, &ifname) < 0) {
 		PMD_INIT_LOG(ERR, "virtio_user_dev_init fails");
 		virtio_user_eth_dev_free(eth_dev);
 		goto end;
@@ -447,6 +462,8 @@
 		free(path);
 	if (mac_addr)
 		free(mac_addr);
+	if (ifname)
+		free(ifname);
 	return ret;
 }
 
@@ -492,4 +509,5 @@
 	"mac=<mac addr> "
 	"cq=<int> "
 	"queue_size=<int> "
-	"queues=<int>");
+	"queues=<int> "
+	"iface=<string>");
-- 
1.8.3.1