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=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_2 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 42D1FECE58C for ; Fri, 11 Oct 2019 13:33:55 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 0ECB22084C for ; Fri, 11 Oct 2019 13:33:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="uICuxm3V" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0ECB22084C 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+infradead-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=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: 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=aKAh0iCAz5sk/0x1Z8uJAETLwkwAT1Y6Heck4i+0y4U=; b=uICuxm3V6yKm9K oUSqS9iTAOpVaFx6oqXOPGrjWCB9eiyol5uajMxqco3YVgr0FtSU0IT6oLyRiYtil/lg9+T6u0Ph0 SAFYxBfFEVumBcqXCPlmYoUR6a7H8LyPkpAhKmKR9PX9d1R1TK+HJaQJaKKT+hlvi9dzt5SmOT7LH BtZjZ8Abn66rCjIFYFCP7xt2UN2NwlHXkmUoxShg1LGdKc/W/dHkXMlfAkigG2xWSQoYF3rIApU13 hz8sC5IoIB/+Co60umNH31V7C8p1SloRDB/TpZteGY4YIV6TDPL9O38S/g4WGZVXolzD6Sp/R4EwM GofC9WRlasGeGJ1yo+Eg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iIv3K-0004ku-5c; Fri, 11 Oct 2019 13:33:54 +0000 Received: from inca-roads.misterjones.org ([213.251.177.50]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iIv3H-0004jx-9c for linux-arm-kernel@lists.infradead.org; Fri, 11 Oct 2019 13:33:52 +0000 Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why) by cheepnis.misterjones.org with esmtpsa (TLSv1.2:AES256-GCM-SHA384:256) (Exim 4.80) (envelope-from ) id 1iIv3A-000788-Pa; Fri, 11 Oct 2019 15:33:44 +0200 Date: Fri, 11 Oct 2019 14:33:43 +0100 From: Marc Zyngier To: Mark Rutland Subject: Re: Relax CPU features sanity checking on heterogeneous architectures Message-ID: <20191011143343.541da66c@why> In-Reply-To: <20191011105010.GA29364@lakrids.cambridge.arm.com> References: <20191011105010.GA29364@lakrids.cambridge.arm.com> Organization: Approximate X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: mark.rutland@arm.com, saiprakash.ranjan@codeaurora.org, rnayak@codeaurora.org, suzuki.poulose@arm.com, catalin.marinas@arm.com, 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 X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on cheepnis.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191011_063351_484903_35FDADC7 X-CRM114-Status: GOOD ( 10.45 ) 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: Sai Prakash Ranjan , rnayak@codeaurora.org, suzuki.poulose@arm.com, catalin.marinas@arm.com, 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 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, 11 Oct 2019 11:50:11 +0100 Mark Rutland wrote: > Hi, > > On Fri, Oct 11, 2019 at 11:19:00AM +0530, Sai Prakash Ranjan wrote: > > On latest QCOM SoCs like SM8150 and SC7180 with big.LITTLE arch, below > > warnings are observed during bootup of big cpu cores. > > For reference, which CPUs are in those SoCs? > > > SM8150: > > > > [ 0.271177] CPU features: SANITY CHECK: Unexpected variation in > > SYS_ID_AA64PFR0_EL1. Boot CPU: 0x00000011112222, CPU4: 0x00000011111112 > > The differing fields are EL3, EL2, and EL1: the boot CPU supports > AArch64 and AArch32 at those exception levels, while the secondary only > supports AArch64. > > Do we handle this variation in KVM? We do, at least at vcpu creation time (see kvm_reset_vcpu). But if one of the !AArch32 CPU comes in late in the game (after we've started a guest), all bets are off (we'll schedule the 32bit guest on that CPU, enter the guest, immediately take an Illegal Exception Return, and return to userspace with KVM_EXIT_FAIL_ENTRY). Not sure we could do better, given the HW. My preference would be to fail these CPUs if they aren't present at boot time. M. -- Jazz is not dead. It just smells funny... _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel