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Date:   Tue, 12 Jul 2022 17:01:59 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     Lior Nahmanson <liorna@nvidia.com>
Cc:     Paolo Abeni <pabeni@redhat.com>,
        "edumazet@google.com" <edumazet@google.com>,
        "davem@davemloft.net" <davem@davemloft.net>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        Raed Salem <raeds@nvidia.com>, Jiri Pirko <jiri@nvidia.com>,
        Saeed Mahameed <saeedm@nvidia.com>,
        Yossi Kuperman <yossiku@nvidia.com>
Subject: Re: [PATCH net-next v3 2/3] net/macsec: Add MACsec skb extension Rx
 Data path support
Message-ID: <20220712170159.6da38d1b@kernel.org>
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On Tue, 12 Jul 2022 06:50:52 +0000 Lior Nahmanson wrote:
> i considered the usage of skb_metadata_dst, however i still think
> that skb_ext will fit more to MACsec offload implementation for the following reasons:
> 1. for Rx, each skb can have a different SCI and offloaded values which mandate allocation
>     of metadata_dst for each skb which contradicts the desired usage for skb_metadata_dst where
>     it's allocated once and a refcnt held whenever used.

How many distinct SCIs do you expect to see?

> 2. skb_ext method is used in a similar IPsec offload implementation which in the future could make it easier
>     to refactor this section to unify all crypto offloads skb_ext usage.

MACSec is L2, IPsec has constraints we have to work around.