From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0E12BC433E0 for ; Fri, 12 Feb 2021 12:36:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CE1FA64E30 for ; Fri, 12 Feb 2021 12:36:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230404AbhBLMgy (ORCPT ); Fri, 12 Feb 2021 07:36:54 -0500 Received: from mail.kernel.org ([198.145.29.99]:54016 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229907AbhBLMgu (ORCPT ); Fri, 12 Feb 2021 07:36:50 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0A4B564DEE; Fri, 12 Feb 2021 12:36:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1613133369; bh=cnTIOUrwbSss0NsP381REUNNVtv0SaySoeMM4ym6xLs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=RdlEud5Vcwv7Bbex5r6Y2fe3o5GEdrpUXdmwC0fYOpCiL0irjf7O+vggKqq0yhlSZ Dgsz/WmSW5yJs2O+61tMAy9BcqrM+RH3X1cNRDsmN1SA1MbaATctkDSdVMV1xxdVGG A/+ZR/RWTWI8VZdTA8B7rzmUekXxmkr/QiRN3IxmXk3p+nZxCvzaYYV+US91+Y8gqi 0tTIkwnob0V+vuLPht5lZD4a+ikD83oj4+4he7+4Dr5aTLDheqSRdd6g5LyUtJUhw1 m0hBkXbZMzeNZFdoVVH7Jy2km0smiY+44p8m8QYJfN5IbCTHhNhQ/UTIr8AfBvmRD5 JqfoLrfPW/UBA== Date: Fri, 12 Feb 2021 12:35:15 +0000 From: Mark Brown To: Steven Price Cc: sonicadvance1@gmail.com, amanieu@gmail.com, Catalin Marinas , Will Deacon , Mark Rutland , Oleg Nesterov , Al Viro , Dave Martin , Amit Daniel Kachhap , Marc Zyngier , David Brazdil , Jean-Philippe Brucker , Andrew Morton , Anshuman Khandual , Gavin Shan , Mike Rapoport , Vincenzo Frascino , Kristina Martsenko , Kees Cook , Sami Tolvanen , Frederic Weisbecker , Kevin Hao , Jason Yan , Andrey Ignatov , Peter Collingbourne , Julien Grall , Tian Tao , Qais Yousef , Jens Axboe , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [RESEND RFC PATCH v2] arm64: Exposes support for 32-bit syscalls Message-ID: <20210212123515.GC6057@sirena.org.uk> References: <20210211202208.31555-1-Sonicadvance1@gmail.com> <58b03e17-3729-99ea-8691-0d735a53b9bc@arm.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="Md/poaVZ8hnGTzuv" Content-Disposition: inline In-Reply-To: <58b03e17-3729-99ea-8691-0d735a53b9bc@arm.com> X-Cookie: One size fits all. User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --Md/poaVZ8hnGTzuv Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, Feb 12, 2021 at 11:30:41AM +0000, Steven Price wrote: > On 11/02/2021 20:21, sonicadvance1@gmail.com wrote: > > Why do we need compatibility layers? > > There are ARMv8 CPUs that only support AArch64 but still need to run > > AArch32 applications. > > Cortex-A34/R82 and other cores are prime examples of this. > > Additionally if a user is needing to run legacy 32-bit x86 software, it > > needs the same compatibility layer. > Unless I'm much mistaken QEMU's user mode already does this - admittedly I > don't tend to run "legacy 32-bit x86 software". Yes, this has been deployed on Debian for a long time - you can install any combination of Debian architectures on a single system and it will use qemu to run binaries that can't be supported natively by the hardware. --Md/poaVZ8hnGTzuv Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmAmdgIACgkQJNaLcl1U h9Ar6Qf7Be9ErKtx5lm+ZTtLIlBvwbYKuCANK8wuDnCzLybGOxE/0n+OHlsJsPoh +HgRSrSab9IvlOcPXxJZ7tWr81ZW8JHdP+gVAKV2ogYn18IWni9jiFw1ti1qru6m y8ow6AFHYS2BryKDPchKalvl3iKVcYGkWvtZVwvK0+0K6PkWCNOIRKI7vRNbqXKa EvMjgvlb//CumMk6TnW3TajWnK5SCpoUN8aP+s5+SJsAsOwpySsum2lwNDXqc1R1 2xYXdB1pgtWgjA7WtasM1W0xwAJ8ol81BaU6FzFXToOPBxg31dff/9dQHXuSyedk r6DqAhGK+pyhY6mhQJvV5jTzaPad+A== =UG5o -----END PGP SIGNATURE----- --Md/poaVZ8hnGTzuv-- From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A2126C433E0 for ; Fri, 12 Feb 2021 12:37:20 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6281264E36 for ; Fri, 12 Feb 2021 12:37:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6281264E36 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Type:Cc: List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: In-Reply-To:MIME-Version:References:Message-ID:Subject:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=q5OiNzUNfSyJ2bGSoZhgUkHmKKcolqwZLT8ccPHzGpY=; b=Rk6+izW9KQuII4TxHUD/WJMhC uZ6RSLeNnnc2qSDuG4WVmuzEoG5QNWSZfMEVyF4GB7wtUmWEllJaNKOOLimF3V2yAWRUrRKAM/rnk X059hmsv7TNaL/fxSXQRtEKKsvPry84p+ok8+/Lvba8UCJFSA8LwavKeeYa9mWbyJmg5VBKve1bVC vZgCnHhdMmJrizJ+l0TuOQIwsJn1aM5rtLNfwgr6RUl+fsOZlsHMzhKs7AOTQYi87KdF3EmwSaxax 1vBc4L+K5sDd7HBly1Axz69VTAW5B6JNUZTRnFO2w44dhdgQxmhzkLM8x5nOHi16z/i5zjhLYt165 QUeQD4R+Q==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1lAXgD-0003yJ-65; Fri, 12 Feb 2021 12:36:13 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1lAXgA-0003xk-UG for linux-arm-kernel@lists.infradead.org; Fri, 12 Feb 2021 12:36:11 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0A4B564DEE; Fri, 12 Feb 2021 12:36:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1613133369; bh=cnTIOUrwbSss0NsP381REUNNVtv0SaySoeMM4ym6xLs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=RdlEud5Vcwv7Bbex5r6Y2fe3o5GEdrpUXdmwC0fYOpCiL0irjf7O+vggKqq0yhlSZ Dgsz/WmSW5yJs2O+61tMAy9BcqrM+RH3X1cNRDsmN1SA1MbaATctkDSdVMV1xxdVGG A/+ZR/RWTWI8VZdTA8B7rzmUekXxmkr/QiRN3IxmXk3p+nZxCvzaYYV+US91+Y8gqi 0tTIkwnob0V+vuLPht5lZD4a+ikD83oj4+4he7+4Dr5aTLDheqSRdd6g5LyUtJUhw1 m0hBkXbZMzeNZFdoVVH7Jy2km0smiY+44p8m8QYJfN5IbCTHhNhQ/UTIr8AfBvmRD5 JqfoLrfPW/UBA== Date: Fri, 12 Feb 2021 12:35:15 +0000 From: Mark Brown To: Steven Price Subject: Re: [RESEND RFC PATCH v2] arm64: Exposes support for 32-bit syscalls Message-ID: <20210212123515.GC6057@sirena.org.uk> References: <20210211202208.31555-1-Sonicadvance1@gmail.com> <58b03e17-3729-99ea-8691-0d735a53b9bc@arm.com> MIME-Version: 1.0 In-Reply-To: <58b03e17-3729-99ea-8691-0d735a53b9bc@arm.com> X-Cookie: One size fits all. User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210212_073611_075724_D5E6FA67 X-CRM114-Status: GOOD ( 16.03 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Gavin Shan , Catalin Marinas , linux-kernel@vger.kernel.org, Julien Grall , Amit Daniel Kachhap , Vincenzo Frascino , Will Deacon , Qais Yousef , Jean-Philippe Brucker , Marc Zyngier , Anshuman Khandual , Andrey Ignatov , Sami Tolvanen , David Brazdil , Dave Martin , Kees Cook , sonicadvance1@gmail.com, Frederic Weisbecker , Kristina Martsenko , Al Viro , amanieu@gmail.com, Peter Collingbourne , linux-arm-kernel@lists.infradead.org, Jens Axboe , Kevin Hao , Jason Yan , Oleg Nesterov , Tian Tao , Andrew Morton , Mike Rapoport Content-Type: multipart/mixed; boundary="===============5672032808660794826==" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org --===============5672032808660794826== Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="Md/poaVZ8hnGTzuv" Content-Disposition: inline --Md/poaVZ8hnGTzuv Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, Feb 12, 2021 at 11:30:41AM +0000, Steven Price wrote: > On 11/02/2021 20:21, sonicadvance1@gmail.com wrote: > > Why do we need compatibility layers? > > There are ARMv8 CPUs that only support AArch64 but still need to run > > AArch32 applications. > > Cortex-A34/R82 and other cores are prime examples of this. > > Additionally if a user is needing to run legacy 32-bit x86 software, it > > needs the same compatibility layer. > Unless I'm much mistaken QEMU's user mode already does this - admittedly I > don't tend to run "legacy 32-bit x86 software". Yes, this has been deployed on Debian for a long time - you can install any combination of Debian architectures on a single system and it will use qemu to run binaries that can't be supported natively by the hardware. --Md/poaVZ8hnGTzuv Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmAmdgIACgkQJNaLcl1U h9Ar6Qf7Be9ErKtx5lm+ZTtLIlBvwbYKuCANK8wuDnCzLybGOxE/0n+OHlsJsPoh +HgRSrSab9IvlOcPXxJZ7tWr81ZW8JHdP+gVAKV2ogYn18IWni9jiFw1ti1qru6m y8ow6AFHYS2BryKDPchKalvl3iKVcYGkWvtZVwvK0+0K6PkWCNOIRKI7vRNbqXKa EvMjgvlb//CumMk6TnW3TajWnK5SCpoUN8aP+s5+SJsAsOwpySsum2lwNDXqc1R1 2xYXdB1pgtWgjA7WtasM1W0xwAJ8ol81BaU6FzFXToOPBxg31dff/9dQHXuSyedk r6DqAhGK+pyhY6mhQJvV5jTzaPad+A== =UG5o -----END PGP SIGNATURE----- --Md/poaVZ8hnGTzuv-- --===============5672032808660794826== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --===============5672032808660794826==--