Received-SPF: pass (google.com: best guess record for domain of linux-crypto-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <20191108122240.28479-1-ardb@kernel.org> <20191115060727.eng4657ym6obl4di@gondor.apana.org.au>
 <CAHmME9oOfhv6RN00m1c6c5qELC5dzFKS=mgDBQ-stVEWu00p_A@mail.gmail.com>
 <20191115090921.jn45akou3cw4flps@gondor.apana.org.au> <CAHmME9rxGp439vNYECm85bgibkVyrN7Qc+5v3r8QBmBXPZM=Dg@mail.gmail.com>
 <CAKv+Gu96xbhS+yHbEjx6dD-rOcB8QYp-Gnnc3WMWfJ9KVbJzcg@mail.gmail.com>
In-Reply-To: <CAKv+Gu96xbhS+yHbEjx6dD-rOcB8QYp-Gnnc3WMWfJ9KVbJzcg@mail.gmail.com>
From:   "Jason A. Donenfeld" <Jason@zx2c4.com>
Date:   Tue, 19 Nov 2019 16:44:11 +0100
Message-ID: <CAHmME9qRwA6yjwzoy=awWdyz40Lozf01XY2xxzYLE+G8bKsMzA@mail.gmail.com>
Subject: Re: [PATCH v5 00/34] crypto: crypto API library interfaces for WireGuard
To:     Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc:     Herbert Xu <herbert@gondor.apana.org.au>,
        Ard Biesheuvel <ardb@kernel.org>,
        Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
        David Miller <davem@davemloft.net>,
        Samuel Neves <sneves@dei.uc.pt>, Arnd Bergmann <arnd@arndb.de>,
        Eric Biggers <ebiggers@google.com>,
        Andy Lutomirski <luto@kernel.org>,
        Martin Willi <martin@strongswan.org>,
        Rene van Dorst <opensource@vdorst.com>,
        David Sterba <dsterba@suse.com>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-crypto-owner@vger.kernel.org
Precedence: bulk

On Tue, Nov 19, 2019 at 4:34 PM Ard Biesheuvel
<ard.biesheuvel@linaro.org> wrote:
> > - Zinc's generic C implementation of poly1305, which is faster and has
> > separate implementations for u64 and u128.

I assume your AndyP comment below didn't apply to this top item here.
This one should be fairly uncontroversial in your opinion, right?

> > - x86_64 ChaCha20 from Zinc. Will be fun to discuss with Martin and Andy.
> > - x86_64 Poly1305 from Zinc.
>
> As I pointed out in the private discussions we had, there are two
> aspects two AndyP's benchmarking that don't carry over 100% to the
> Linux kernel:
> - Every microarchitecture is given equal weight, regardless of the
> likelihood that the code will actually run on it. This makes some
> sense for OpenSSL, I guess, but not for the kernel.
> - Benchmarks are typically based on the performance of the core
> cryptographics transformation rather than a representative workload.
> This is especially relevant for network use cases, where packet sizes
> are not necessarily fixed and usually not a multiple of the block size
> (as opposed to disk encryption, where every single call is the same
> size and a power of 2)
>
> So for future changes, could we please include performance numbers
> based on realistic workloads?

Yea I share your concerns here. From preliminary results, I think the
Poly1305 code will be globally better, and I don't think we'll need an
abundance of discussion about it.

The ChaCha case is more interesting. I'll submit this with lots of
packet-sized microbenchmarks, as well as on-the-wire WireGuard
testing. Eric - I'm guessing you don't care too much about Adamantium
performance on x86 where people are probably better off with AES-XTS,
right? Are there other specific real world cases we care about? IPsec
is another one, but those concerns, packet-size wise, are more or less
the same as for WireGuard. But anyway, we can cross this bridge when
we come to it.


> > - WireGuard! Hurrah!
> >
> I'm a bit surprised that this only appears at the end of your list :-)

Haha, "last but not least" :)

>
> > If you have any feedback on how you'd like this prioritized, please
> > pipe up. For example Dave - would you like WireGuard *now* or sometime
> > later? I can probably get that cooking this week, though I do have
> > some testing and fuzzing of it to do on top of the patches that just
> > landed in cryptodev.
> >
>
> We're at -rc8, and wireguard itself will not go via the crypto tree so
> you should wait until after the merge window, rebase it onto -rc1 and
> repost it.

Thanks, yea, that makes sense. Netdev also has its own merge window
schedule that I should aim to meet. I guess, based on this if I'm
understanding correctly, we're looking at WireGuard for 5.5?

Jason