From mboxrd@z Thu Jan  1 00:00:00 1970
From: Zoltan Kiss <zoltan.kiss@citrix.com>
Subject: Re: RING_HAS_UNCONSUMED_REQUESTS oddness
Date: Thu, 13 Mar 2014 12:28:31 +0000
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To: Ian Campbell <Ian.Campbell@citrix.com>, Paul Durrant <Paul.Durrant@citrix.com>
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On 13/03/14 12:19, Ian Campbell wrote:
> On Thu, 2014-03-13 at 10:58 +0000, Paul Durrant wrote:
>>> -----Original Message-----
>>> From: Ian Campbell
>>> Sent: 13 March 2014 10:03
>>> To: Paul Durrant
>>> Cc: Zoltan Kiss; Wei Liu; xen-devel@lists.xenproject.org; Tim (Xen.org)
>>> Subject: Re: [Xen-devel] RING_HAS_UNCONSUMED_REQUESTS oddness
>>>
>>> On Thu, 2014-03-13 at 09:26 +0000, Paul Durrant wrote:
>>>> guarantee that netback will always respond in order on the rx ring.
>>>
>>> I don't believe this is guaranteed byt the protocol, even if it happens
>>> to work out that way for the Linux netback implementation.
>>>
>>
>> Indeed it's not guaranteed by the protocol but it's the only way that
>> (non-prefix) GSO can possibly work, which is why I think something
>> really needs to be documented.
>
> There are possibly ordering constraints on the completion of the gso
> info slot and the rest but I don't think there are any such restrictions
> on the fragment slots themselves, are there?

Well, the Linux frontend doesn't take the id from the response, it just 
assume that the response is in the same slot as the request.