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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 5FE95C433E9 for ; Thu, 18 Feb 2021 17:18:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2D24164ED0 for ; Thu, 18 Feb 2021 17:18:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234139AbhBRRSS (ORCPT ); Thu, 18 Feb 2021 12:18:18 -0500 Received: from foss.arm.com ([217.140.110.172]:51814 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231486AbhBROhp (ORCPT ); Thu, 18 Feb 2021 09:37:45 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6652DED1; Thu, 18 Feb 2021 06:36:50 -0800 (PST) Received: from C02TD0UTHF1T.local (unknown [10.57.48.237]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 823063F73B; Thu, 18 Feb 2021 06:36:47 -0800 (PST) Date: Thu, 18 Feb 2021 14:36:44 +0000 From: Mark Rutland To: Hector Martin Cc: linux-arm-kernel@lists.infradead.org, Marc Zyngier , Rob Herring , Arnd Bergmann , Olof Johansson , Krzysztof Kozlowski , Mark Kettenis , Tony Lindgren , Mohamed Mediouni , Stan Skowronek , Alexander Graf , Will Deacon , Linus Walleij , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 00/25] Apple M1 SoC platform bring-up Message-ID: <20210218143644.GC89209@C02TD0UTHF1T.local> References: <20210215121713.57687-1-marcan@marcan.st> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210215121713.57687-1-marcan@marcan.st> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 15, 2021 at 09:16:48PM +0900, Hector Martin wrote: > This series brings up initial support for the Apple M1 SoC, used in the > 2020 Mac Mini, MacBook Pro, and MacBook Air models. > > The following features are supported in this initial port: > > - UART (samsung-style) with earlycon support > - Interrupts, including affinity and IPIs (Apple Interrupt Controller) > - SMP (through standard spin-table support) > - simplefb-based framebuffer > - Devicetree for the Mac Mini (should work for the others too at this > stage) IIUC, the CPUs in these parts have some IMP-DEF instructions that can be used at EL0 which might have some IMP-DEF state. Our general expectation is that FW should configure such things to trap, but I don't know whether the M1 FW does that, and I fear that this will end up being a problem for us -- even if that doesn't affect EL1/EL2, IMP-DEF state is an interesting covert channel between EL0 tasks, and not generally safe to use thanks to context-switch and idle, so I'd like to make sure we can catch usage and make it SIGILL. Do you happen to know whether all of that is configured to trap, and if not, is it possible to adjust the bootloader to ensure it is? Thanks, Mark. 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=-3.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 E3D94C433DB for ; Thu, 18 Feb 2021 14:39:11 +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 776C064EAD for ; Thu, 18 Feb 2021 14:39:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 776C064EAD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com 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-Transfer-Encoding: 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-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=IauvOMrXntTDek0ZY0dZpmusCn++NDAXwQwKR8Zw0/w=; b=Q0v+fVrIV9JgQJ6z/8RGqKjsh XJMekYwGAxdcd+G0MoU2BMIKdqPNeu1KxGAGUA7Cv/F4pU01WYJoXYgPbepWEK4a1wEPT0/FVbh3W Gghg1tocMOwynZ/0c/xYbuXfNqWViwXZvzfI/dkWfly3mxbvb10sNWhGiTdenk+Msf+eOvOtRjwe3 4WOl08DZGgyGHnl47Xt27CWTjhMtKF7kcp/ueF3d4+iyTS1zGXX2rQVuNOEXgAC22r0KRl4gsg1rM Z7g85DgXpKbfBcqoL8FHnDWtVoxUiDoPH0lHJCrghMY4vsqM1K+QYegQoSOC7ae4b59Z1nkvFMSVv tyO8WnHdg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1lCkQI-0007bt-1p; Thu, 18 Feb 2021 14:36:54 +0000 Received: from foss.arm.com ([217.140.110.172]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1lCkQF-0007bM-QY for linux-arm-kernel@lists.infradead.org; Thu, 18 Feb 2021 14:36:52 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6652DED1; Thu, 18 Feb 2021 06:36:50 -0800 (PST) Received: from C02TD0UTHF1T.local (unknown [10.57.48.237]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 823063F73B; Thu, 18 Feb 2021 06:36:47 -0800 (PST) Date: Thu, 18 Feb 2021 14:36:44 +0000 From: Mark Rutland To: Hector Martin Subject: Re: [PATCH v2 00/25] Apple M1 SoC platform bring-up Message-ID: <20210218143644.GC89209@C02TD0UTHF1T.local> References: <20210215121713.57687-1-marcan@marcan.st> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210215121713.57687-1-marcan@marcan.st> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210218_093651_923264_8787E824 X-CRM114-Status: GOOD ( 18.28 ) 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: Arnd Bergmann , Rob Herring , Tony Lindgren , Marc Zyngier , Linus Walleij , linux-kernel@vger.kernel.org, Krzysztof Kozlowski , devicetree@vger.kernel.org, Alexander Graf , Olof Johansson , Mohamed Mediouni , Stan Skowronek , Will Deacon , linux-arm-kernel@lists.infradead.org, Mark Kettenis 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, Feb 15, 2021 at 09:16:48PM +0900, Hector Martin wrote: > This series brings up initial support for the Apple M1 SoC, used in the > 2020 Mac Mini, MacBook Pro, and MacBook Air models. > > The following features are supported in this initial port: > > - UART (samsung-style) with earlycon support > - Interrupts, including affinity and IPIs (Apple Interrupt Controller) > - SMP (through standard spin-table support) > - simplefb-based framebuffer > - Devicetree for the Mac Mini (should work for the others too at this > stage) IIUC, the CPUs in these parts have some IMP-DEF instructions that can be used at EL0 which might have some IMP-DEF state. Our general expectation is that FW should configure such things to trap, but I don't know whether the M1 FW does that, and I fear that this will end up being a problem for us -- even if that doesn't affect EL1/EL2, IMP-DEF state is an interesting covert channel between EL0 tasks, and not generally safe to use thanks to context-switch and idle, so I'd like to make sure we can catch usage and make it SIGILL. Do you happen to know whether all of that is configured to trap, and if not, is it possible to adjust the bootloader to ensure it is? Thanks, Mark. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel