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To: Pavel Fedin <p.fedin@samsung.com>, dev@dpdk.org
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From: "Tan, Jianfeng" <jianfeng.tan@intel.com>
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Date: Wed, 6 Jan 2016 13:47:28 +0800
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Subject: Re: [dpdk-dev] [RFC 0/5] virtio support for container
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On 12/31/2015 11:39 PM, Pavel Fedin wrote:
>   Hello!
>
>   Last minute note. I have found the problem but have no time to research and fix it.
>   It happens because ovs first creates the device, starts it, then stops it, and reconfigures queues. The second queue allocation
> happens from within netdev_set_multiq(). Then ovs restarts the device and proceeds to actually using it.
>   But, queues are not initialized properly in DPDK after the second allocation. Because of this thing:
>
> 	/* On restart after stop do not touch queues */
> 	if (hw->started)
> 		return 0;
Hi Fedin,

As you see, I also think it is a bug. A device should be ok to 
start/stop/start...

I already send a patch to fix this.
http://dpdk.org/ml/archives/dev/2016-January/031010.html

Thanks,
Jianfeng
>
>   It keeps us away from calling virtio_dev_rxtx_start(), which should in turn call virtio_dev_vring_start(), which calls
> vring_init(). So, VIRTQUEUE_NUSED() dies badly because vq->vq_ring all contains NULLs.
>   See you all after 10th. And happy New Year again!
>
>