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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 82365CA9EA0 for ; Fri, 18 Oct 2019 16:40:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5BCBF2070B for ; Fri, 18 Oct 2019 16:40:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571416842; bh=K2kmdzvZ0PoJaTMqG8RbMV2VFT2lgWX9XMW2rld7+lw=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=WFRdG76HCtgTjz6zK0yXOQhhVuF+txxhPMM9ZCKdDbqhzl7+gMFNYB7XzgId1fmtx EiIFar0zKX9jrYHaxpt0TW5xTxAT7yjQPXAt3juGq3Rb2MkX+haJB196k7B6aWbYth evUoQSJUIetusOzQJENs8kPfnJ8gC2sDetyv37mk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405805AbfJRQkl (ORCPT ); Fri, 18 Oct 2019 12:40:41 -0400 Received: from inca-roads.misterjones.org ([213.251.177.50]:57275 "EHLO inca-roads.misterjones.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728368AbfJRQkk (ORCPT ); Fri, 18 Oct 2019 12:40:40 -0400 Received: from [213.166.56.99] (helo=big-swifty.misterjones.org) by cheepnis.misterjones.org with esmtpsa (TLSv1.2:AES256-GCM-SHA384:256) (Exim 4.80) (envelope-from ) id 1iLVIk-0002nV-PR; Fri, 18 Oct 2019 18:40:30 +0200 Date: Fri, 18 Oct 2019 17:40:29 +0100 Message-ID: <86h846ypky.wl-maz@kernel.org> From: Marc Zyngier To: Stephen Boyd Cc: Sai Prakash Ranjan , Mark Rutland , rnayak@codeaurora.org, suzuki.poulose@arm.com, catalin.marinas@arm.com, linux-arm-kernel , linux-kernel@vger.kernel.org, jeremy.linton@arm.com, bjorn.andersson@linaro.org, linux-arm-msm@vger.kernel.org, andrew.murray@arm.com, will@kernel.org, dave.martin@arm.com, linux-arm-kernel@lists.infradead.org, marc.w.gonzalez@free.fr Subject: Re: Relax CPU features sanity checking on heterogeneous architectures In-Reply-To: <5da9cd3a.1c69fb81.95e9.e5e2@mx.google.com> References: <20191011105010.GA29364@lakrids.cambridge.arm.com> <7910f428bd96834c15fb56262f3c10f8@codeaurora.org> <20191011143442.515659f4@why> <5da8c868.1c69fb81.ae709.97ff@mx.google.com> <5da9cd3a.1c69fb81.95e9.e5e2@mx.google.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 EasyPG/1.0.0 Emacs/26 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 213.166.56.99 X-SA-Exim-Rcpt-To: swboyd@chromium.org, saiprakash.ranjan@codeaurora.org, mark.rutland@arm.com, rnayak@codeaurora.org, suzuki.poulose@arm.com, catalin.marinas@arm.com, linux-arm-kernel-bounces@lists.infradead.org, linux-kernel@vger.kernel.org, jeremy.linton@arm.com, bjorn.andersson@linaro.org, linux-arm-msm@vger.kernel.org, andrew.murray@arm.com, will@kernel.org, dave.martin@arm.com, linux-arm-kernel@lists.infradead.org, marc.w.gonzalez@free.fr X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on cheepnis.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 On Fri, 18 Oct 2019 15:33:29 +0100, Stephen Boyd wrote: > > Quoting Marc Zyngier (2019-10-18 00:20:56) > > > > If this SoC is anythinig like SM8150, 32bit guests will be hit and > > miss, > > depending on the CPU your guest runs on, or is migrated to. We need to > > either drop capabilities from the 32bit-capable CPU, or prevent the > > non-32bit capable CPU from booting if a 32bit guest has been started. > > > > You just have to hope that the kernel is entered at EL2, and that QC's > > "value add" has been moved somewhere else... > > > > Ok that's good. I need a new signature. M. -- Jazz is not dead, it just smells funny.