From mboxrd@z Thu Jan 1 00:00:00 1970 From: Huang Ying Subject: Re: [RFC PATCH crypto] AES: Add support to Intel AES-NI instructions Date: Mon, 15 Dec 2008 13:48:51 +0800 Message-ID: <1229320131.5936.232.camel@yhuang-dev.sh.intel.com> References: <1229054926.5936.160.camel@yhuang-dev.sh.intel.com> <20081212195722.GA24489@Chamillionaire.breakpoint.cc> <1229307542.5936.204.camel@yhuang-dev.sh.intel.com> <20081215033842.GA28499@gondor.apana.org.au> <1229318099.5936.224.camel@yhuang-dev.sh.intel.com> <20081215052106.GA29324@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-nZ3Rj0rY396gsJUsIYn/" Cc: "Siddha, Suresh B" , Sebastian Andrzej Siewior , "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" , "linux-crypto@vger.kernel.org" , "mingo@elte.hu" , "tglx@linutronix.de" To: Herbert Xu Return-path: Received: from mga03.intel.com ([143.182.124.21]:48695 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750904AbYLOFsy (ORCPT ); Mon, 15 Dec 2008 00:48:54 -0500 In-Reply-To: <20081215052106.GA29324@gondor.apana.org.au> Sender: linux-crypto-owner@vger.kernel.org List-ID: --=-nZ3Rj0rY396gsJUsIYn/ Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Mon, 2008-12-15 at 13:21 +0800, Herbert Xu wrote: > On Mon, Dec 15, 2008 at 01:14:59PM +0800, Huang Ying wrote: > >=20 > > The PadLock instructions don't use/touch SSE registers, but might cause > > DNA fault when CR0.TS is set. So it is sufficient just to clear CR0.TS > > before executed. > >=20 > > The AES-NI instructions do use SSE registers. Considering the following >=20 > This really sucks as more than half of the kernel AES users are > in softirq context. Someone hit the guy who designed this with > a clue-bat please! >=20 > > To solve the above issue, the following methods can be used: > >=20 > > a. Do not touch SSE state in soft_irq > > b. Disable/restore soft_irq in kernel_fpu_begin/kernel_fpu_end > > c. Use a per-CPU data structure to save kernel FPU state during > > soft_irq. > >=20 > > The mothod a is used in patch. >=20 > Could you run the tcrypt speed test on this and measure the > difference between the native AES vs. the fallback? Depending > on the difference I think we'd want to consider b) or c). I do not have appropriate machine at hand, I will contact my colleague for testing and post the results later. Best Regards, Huang Ying --=-nZ3Rj0rY396gsJUsIYn/ Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEABECAAYFAklF77wACgkQKhFGF+eHlpj8XgCdF0kGcQCT3q5W9gNiXnugA/s7 4U0An2iecvuNhoing8wIMe5lVKR5NT2V =eMdo -----END PGP SIGNATURE----- --=-nZ3Rj0rY396gsJUsIYn/--