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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham 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 308D6C2BB55 for ; Wed, 15 Apr 2020 10:09:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1670F20768 for ; Wed, 15 Apr 2020 10:09:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2896209AbgDOKJO (ORCPT ); Wed, 15 Apr 2020 06:09:14 -0400 Received: from foss.arm.com ([217.140.110.172]:41362 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2896152AbgDOKJI (ORCPT ); Wed, 15 Apr 2020 06:09:08 -0400 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 BE24F1063; Wed, 15 Apr 2020 03:09:07 -0700 (PDT) Received: from [10.37.12.1] (unknown [10.37.12.1]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7E07D3F68F; Wed, 15 Apr 2020 03:09:05 -0700 (PDT) Subject: Re: [PATCH 3/8] arm64: cpufeature: Add CPU capability for AArch32 EL1 support To: will@kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu Cc: linux-kernel@vger.kernel.org, mark.rutland@arm.com, maz@kernel.org, anshuman.khandual@arm.com, catalin.marinas@arm.com, saiprakash.ranjan@codeaurora.org, dianders@chromium.org, kernel-team@android.com References: <20200414213114.2378-1-will@kernel.org> <20200414213114.2378-4-will@kernel.org> From: Suzuki K Poulose Message-ID: Date: Wed, 15 Apr 2020 11:13:54 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20200414213114.2378-4-will@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/14/2020 10:31 PM, 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 One of the other important missing sanity check for KVM is the VMID width check. I will code something up. Reviewed-by: Suzuki K Poulose