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=-4.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 8CF2DC2BA19 for ; Wed, 15 Apr 2020 08:56:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5028D20775 for ; Wed, 15 Apr 2020 08:56:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586940966; bh=lL08kyfy+9y5wE4bT7FrtRAP9e6Jx76z4bGDZo1tk4s=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=sTSE5hiCPxso1yrIGu2b7CXAjnOSh3XslGfuYV3vIEWQQTBeGh5JTw59QjfhocHXD 71FsZfyEn5CpX/bICi9Jm23YZ5A1+E7ag6hIKIdJGuCn4M6B4JH1ZDCDs2938DRqwx w6Jd6Y5Gvg0e06i+a2pNfCPWQ5C9KWYJ++sqyP18= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405252AbgDOI4F (ORCPT ); Wed, 15 Apr 2020 04:56:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:41700 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404988AbgDOI4A (ORCPT ); Wed, 15 Apr 2020 04:56:00 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 900C520737; Wed, 15 Apr 2020 08:55:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586940959; bh=lL08kyfy+9y5wE4bT7FrtRAP9e6Jx76z4bGDZo1tk4s=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=zPVuO2lg9Bf7O4AyeHVkBbTdBcjJ0l9TTPg+WqJ1AqZYtX9Ksbab4hxQBuS6PhOcz nG946f+z2ldlNfsBvYalLoWeuksyMjcQaVfN7Vrfos3ZdMA9haxjGQx7k25dNYi8JR 3SG+qQmED0JCKXDh2wrsKH9jJipvG+N1lrNGpk3o= Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1jOdpt-003Rlm-Ss; Wed, 15 Apr 2020 09:55:58 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 15 Apr 2020 09:55:57 +0100 From: Marc Zyngier To: Will Deacon Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, Suzuki K Poulose , Mark Rutland , Anshuman Khandual , Catalin Marinas , Sai Prakash Ranjan , Doug Anderson , kernel-team@android.com Subject: Re: [PATCH 3/8] arm64: cpufeature: Add CPU capability for AArch32 EL1 support In-Reply-To: <20200414213114.2378-4-will@kernel.org> References: <20200414213114.2378-1-will@kernel.org> <20200414213114.2378-4-will@kernel.org> Message-ID: <1b76993491176577567a0960a435dac0@kernel.org> X-Sender: maz@kernel.org User-Agent: Roundcube Webmail/1.3.10 X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: will@kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, suzuki.poulose@arm.com, mark.rutland@arm.com, anshuman.khandual@arm.com, catalin.marinas@arm.com, saiprakash.ranjan@codeaurora.org, dianders@chromium.org, 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 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Will, On 2020-04-14 22:31, Will Deacon wrote: > Although we emit a "SANITY CHECK" warning and taint the kernel if we > detect a CPU mismatch for AArch32 support at EL1, we still online the > CPU with disastrous consequences for any running 32-bit VMs. > > Introduce a capability for AArch32 support at EL1 so that late onlining > of incompatible CPUs is forbidden. > > Signed-off-by: Will Deacon Definitely an improvement over the current situation, as the direct read of ID_AA64PFR0 was always a bit dodgy. Given that I'm pretty sure these new braindead SoCs are going to run an older version of the kernel, should we Cc stable for this? Otherwise: Acked-by: Marc Zyngier M. -- Jazz is not dead. It just smells funny...