diff mbox

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

Message ID 1489246618-16898-1-git-send-email-liuwf@arraynetworks.com.cn (mailing list archive)
State Superseded, archived
Delegated to: Yuanhan Liu
Headers

Checks

Context Check Description
ci/Intel-compilation success Compilation OK
ci/checkpatch success coding style OK

Commit Message

Wenfeng Liu March 11, 2017, 3:36 p.m. UTC 
  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(-)

Comments

Yuanhan Liu March 14, 2017, 7:02 a.m. UTC | #1 
On Sat, Mar 11, 2017 at 03:36:58PM +0000, Wenfeng Liu wrote:
> 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>

Jianfeng, any comments?

	--yliu
Jianfeng Tan March 28, 2017, 2:05 a.m. UTC | #2 
Hi Wenfeng,

Thank you for implementing this.

On 3/11/2017 11:36 PM, Wenfeng Liu wrote:
> 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;

If we do not free it here, we need to free it at virtio_user_pmd_remove().

> -
>   	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) {

Any specific reason for above change? What if we set 
VIRTIO_USER_DEF_CQ_EN=1 in future? I think zero is more clear.

Thanks,
Jianfeng
Wenfeng Liu March 28, 2017, 3:02 a.m. UTC | #3 
Hi Jianfeng,

At 2017-03-28 10:05:11, "Tan, Jianfeng" <jianfeng.tan@intel.com> wrote:
>Hi Wenfeng,
>
>Thank you for implementing this.
>
>On 3/11/2017 11:36 PM, Wenfeng Liu wrote:
>> 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;
>
>If we do not free it here, we need to free it at virtio_user_pmd_remove().

Yes, I put the free in virtio_user_dev_uninit(), which will be called by
virtio_user_pmd_remove().

>
>> -
>>   	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);

Here is the free in virtio_user_dev_uninit().

>>   }
>>   
>>   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) {
>
>Any specific reason for above change? What if we set 
>VIRTIO_USER_DEF_CQ_EN=1 in future? I think zero is more clear.

Because cq was initialized to VIRTIO_USER_DEF_CQ_EN in this function, I
thought this comparison was intend to tell whether cq had been given a
different value, so I used 
VIRTIO_USER_DEF_CQ_EN instead the magic number 0. Did I understand this
correctly? If not, I am happy to change it back.
>
>Thanks,
>Jianfeng
>
Jianfeng Tan March 28, 2017, 3:40 a.m. UTC | #4 
On 3/28/2017 11:02 AM, Wenfeng Liu wrote:
> Hi Jianfeng,
>
> At 2017-03-28 10:05:11, "Tan, Jianfeng" <jianfeng.tan@intel.com> wrote:
>> Hi Wenfeng,
>>
>> Thank you for implementing this.
>>
>> On 3/11/2017 11:36 PM, Wenfeng Liu wrote:
>>> 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;
>> If we do not free it here, we need to free it at virtio_user_pmd_remove().
> Yes, I put the free in virtio_user_dev_uninit(), which will be called by
> virtio_user_pmd_remove().
>
>>> -
>>>    	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);
> Here is the free in virtio_user_dev_uninit().

Oops, I missed that.

>
>>>    }
>>>    
>>>    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) {
>> Any specific reason for above change? What if we set
>> VIRTIO_USER_DEF_CQ_EN=1 in future? I think zero is more clear.
> Because cq was initialized to VIRTIO_USER_DEF_CQ_EN in this function, I
> thought this comparison was intend to tell whether cq had been given a
> different value, so I used
> VIRTIO_USER_DEF_CQ_EN instead the magic number 0. Did I understand this
> correctly? If not, I am happy to change it back.

No, our purpose is not to check if cq is assigned a different value. We 
are checking if cq is enabled or not as mq requires cq.

Besides that, it looks good to me.

Reviewed-by: Jianfeng Tan <jianfeng.tan@intel.com>
diff mbox

Patch

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>");