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Date: Thu, 04 Jun 2015 17:35:41 +0800
From: Jason Wang <jasowang@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH 1/1] net: fix queue's purge on VM stop
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To: Stefan Hajnoczi <stefanha@gmail.com>
Cc: Thibaut Collet <thibaut.collet@6wind.com>, qemu-devel <qemu-devel@nongnu.org>, Vincenzo Maffione <v.maffione@gmail.com>, Stefan Hajnoczi <stefanha@redhat.com>, Giuseppe Lettieri <g.lettieri@iet.unipi.it>, Luigi Rizzo <rizzo@iet.unipi.it>



On 06/03/2015 09:40 PM, Stefan Hajnoczi wrote:
> On Wed, Jun 3, 2015 at 10:42 AM, Jason Wang <jasowang@redhat.com> wrote:
>>
>> On 06/03/2015 03:56 PM, Thibaut Collet wrote:
>>> Hi,
>>>
>>> thanks for your point, I did not notice the problem of the lost of ARP
>>> announce by discarding the message.
>>> So I must rewrite my patch to define a queue to transmit the ARP
>>> announce to the guest. Is it the proper solution?
>>>
>> Please have a look at VIRTIO_NET_F_GUEST_ANNOUNCE. It can notify guest
>> after migration to let it to send arp announce. Recent linux driver has
>> this support.
> This looks like a useful feature.
>
> I couldn't see a place in the code where qemu_announce_self() skips
> virtio-net NICs that have this feature bit enabled.  Does this mean
> these NICs will send announces twice (once from the guest and once
> from QEMU)?

Yes, for simplicity, the changes were limited to virito-net only.

>
> My hope was that with the virtio-net announce feature the
> qemu_announce_self() function would skip the NIC.
>
> Stefan

Yes and will try to post patch to do this.

Thanks