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Date: Fri, 10 Nov 2023 15:17:10 -0800
From: Jakub Kicinski <kuba@kernel.org>
To: Stanislav Fomichev <sdf@google.com>
Cc: Eric Dumazet <edumazet@google.com>, Mina Almasry
 <almasrymina@google.com>, Willem de Bruijn
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 Paolo Abeni <pabeni@redhat.com>, Jesper Dangaard Brouer <hawk@kernel.org>,
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 <christian.koenig@amd.com>, Shakeel Butt <shakeelb@google.com>, Jeroen de
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 Willem de Bruijn <willemb@google.com>, Kaiyuan Zhang <kaiyuanz@google.com>
Subject: Re: [RFC PATCH v3 09/12] net: add support for skbs with unreadable
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On Tue, 7 Nov 2023 14:23:20 -0800 Stanislav Fomichev wrote:
> Can we mark a socket as devmem-only? Do we have any use-case for those
> hybrid setups? Or, let me put it that way: do we expect API callers
> to handle both linear and non-linear cases correctly?
> As a consumer of the previous versions of these apis internally,
> I find all those corner cases confusing :-( Hence trying to understand
> whether we can make it a bit more rigid and properly defined upstream.

FWIW I'd also prefer to allow mixing. "Some NICs" can decide HDS
very flexibly, incl. landing full jumbo frames into the "headers".

There's no sender API today to signal how to mark the data for
selective landing,  but if Mina already has the rx side written 
to allow that...