From mboxrd@z Thu Jan  1 00:00:00 1970
From: chetan L <loke.chetan@gmail.com>
Subject: Re: [RFC PATCH 01/14] packet: introduce AF_PACKET V4 userspace API
Date: Thu, 16 Nov 2017 11:32:55 -0800
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To: David Miller <davem@davemloft.net>
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On Wed, Nov 15, 2017 at 5:44 PM, David Miller <davem@davemloft.net> wrote:
> From: chet l <loke.chetan@gmail.com>
> Date: Wed, 15 Nov 2017 14:34:32 -0800
>
>> I have not reviewed the entire patchset but I think if we could add a
>> version_hdr and then unionize the fields, it might be easier to add
>> SVM support without having to spin v5. I could be wrong though.
>
> Please, NO VERSION FIELDS!
>
> Design things properly from the start rather than using a crutch of
> being able to "adjust things later".

Agreed. If this step in tpkt_v4 is able to follow what req1/2/3 did as
part of the setsockopt(..) API then it should be ok. If its a
different API then it will be difficult for the follow-on version(s)
to make seamless changes.

Look at tpacket_req3 for example. Since there was no hdr, I had no
option but to align the fields with tpacket_req/req2 during the setup.
I won't have access to a SMMUv3 capable ARM platform anytime soon. So
I can't actually test/write anything as of now.


Chetan