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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E3070CCA473 for ; Mon, 27 Jun 2022 15:31:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Subject:Cc:To:From:Message-ID:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=LFe//JP+02rWm21BF9f30V4PstrQAxZPOUFOEOsdcdk=; b=4abvlR28dt+q+F ol5RKE7ZP5yQ7r4Y2SM9bT6MVz09UsggU/fW+ze9tr7U1OEiuhEYhmDmLoV1QuI579t3bg6wbmUUd 14GyeCMU0TCcFDsz+deuLG64jTnSfXONgV2Gbw9xQEft72L4xRY2aad7v1JzdoyTfZVxB2yawnBmy RUBuhqqEETbi6q9RbKvkAqmihtaqidr//RjCbl+sZ7WOEzPtba2ZE/j7LDU+3eHZNK7EDipIpJp3a dXv7Q7YROaNlD9cMdH0uuBkjyVEsqoYYVCH2MTzj4lm0dJznBrZcgvPwgryQeIVJcA20HmLXt4qTR ViZe4XwfUQwHfWrVyfuA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o5qhI-001eQc-G0; Mon, 27 Jun 2022 15:30:44 +0000 Received: from ams.source.kernel.org ([2604:1380:4601:e00::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1o5qhF-001ePu-N1 for linux-arm-kernel@lists.infradead.org; Mon, 27 Jun 2022 15:30:43 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 60F12B81884; Mon, 27 Jun 2022 15:30:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 12168C3411D; Mon, 27 Jun 2022 15:30:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1656343839; bh=dFYEPoYpuuYeWjpgm0/I3Alv7PZFpa/Hn3KJQS9cgLs=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=eSpgnIk8L0Cq2N7XHsOySo2LL3RIf7nte+y4L8xzJb8/bHEnBy5VvxEGM/Lc910ud nM2Fa8Or/P8vBstRXk3V+2N83Qbq2QV1Z0oykRzMJLZtucwDc425QRkZrlxYN0i+RJ sbifsb4pOM8fhARE9rRcdCRICUhyxcOl/BHR545Qd2GAFt2Nkl/alpoNt8OVRUrndw jvxIjrPp0BdzRztGTwYvSsx5aGi/MFGQEkT1n1Ll0l+DVdCEzxykyWtAYwzAWAi1ht xLdsbKk9otXgc0aCPQ+wdUsCoEZf4qZb9jM0CXqLKIxNKAKy2Ph8UwAwu+EfzoiiEE YbfOknMNCSXdg== Received: from sofa.misterjones.org ([185.219.108.64] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1o5qhA-003UDn-Op; Mon, 27 Jun 2022 16:30:36 +0100 Date: Mon, 27 Jun 2022 16:30:36 +0100 Message-ID: <878rpi2kf7.wl-maz@kernel.org> From: Marc Zyngier To: Mark Brown Cc: linux-arm-kernel@lists.infradead.org, Will Deacon , Catalin Marinas , Mark Rutland , Ard Biesheuvel , danielmentz@google.com, saravanak@google.com, kernel-team@android.com Subject: Re: [PATCH 0/6] arm64: Disabling SVE/SME from the command-line In-Reply-To: References: <20220627151412.1496361-1-maz@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: broonie@kernel.org, linux-arm-kernel@lists.infradead.org, will@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com, ardb@kernel.org, danielmentz@google.com, saravanak@google.com, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220627_083041_931270_A2D44F06 X-CRM114-Status: GOOD ( 21.97 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, 27 Jun 2022 16:18:36 +0100, Mark Brown wrote: > > On Mon, Jun 27, 2022 at 04:14:06PM +0100, Marc Zyngier wrote: > > > The main victim here is SVE, because it seems that people have all > > sort of broken firmware out there, and that a distribution kernel > > cannot boot on that. And since we have a dependency between SVE and > > SME, disabling the former also disables the latter. > > Oh dear, I've not seen any reports of this. I'm guessing it's TF-A just > not enabling the requisite traps, coupled with people using prebuilt > kernels that turned off SVE when doing validation? Most probably something along these lines. The case I'm aware of involves booting a vanilla kernel on a system with a half baked firmware. I have little sympathy for these systems, but this looks like a reasonable ask to be able to disable a feature from the command line in order to pinpoint the issue. Will someone ship a system with this baked into the command line? I don't believe it for a second (/me ducks). M. -- Without deviation from the norm, progress is not possible. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel