From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Tan, Jianfeng" <jianfeng.tan@intel.com>
Subject: Re: [PATCH v2 5/7] net/virtio_user: add vhost kernel
 support
Date: Wed, 11 Jan 2017 10:30:46 +0800
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Cc: yuanhan.liu@linux.intel.com, ferruh.yigit@intel.com,
 cunming.liang@intel.com
To: Jason Wang <jasowang@redhat.com>, dev@dpdk.org
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Hi Jason,


On 1/9/2017 12:39 PM, Jason Wang wrote:
>> +    if (!enable) {
>> +        if (dev->tapfds[pair_idx]) {
>> +            close(dev->tapfds[pair_idx]);
>> +            dev->tapfds[pair_idx] = -1;
>> +        }
>> +        return vhost_kernel_set_backend(vhostfd, -1);
>
> If this is used to for thing like ethtool -L in guest, we should use 
> TUNSETQUEUE here.

To make it clear, why we need to ioctl(..., TUNSETQUEUE, ...) here. 
According to Linux/Documentation/networking/tuntap.txt,
     "A new ioctl(TUNSETQUEUE) were introduced to enable or disable a 
queue. When
     calling it with IFF_DETACH_QUEUE flag, the queue were disabled. And 
when
     calling it with IFF_ATTACH_QUEUE flag, the queue were enabled. The 
queue were
     enabled by default after it was created through TUNSETIFF."

As it's enabled by default, do you still see the necessity to call it 
explicitly?

Thanks,
Jianfeng