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

[Wenfeng Liu]

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 <li...@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