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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 765E2C43381 for ; Mon, 25 Mar 2019 10:59:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 49D0D20863 for ; Mon, 25 Mar 2019 10:59:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730842AbfCYK7k (ORCPT ); Mon, 25 Mar 2019 06:59:40 -0400 Received: from foss.arm.com ([217.140.101.70]:45372 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730633AbfCYK7j (ORCPT ); Mon, 25 Mar 2019 06:59:39 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 098301596; Mon, 25 Mar 2019 03:59:39 -0700 (PDT) Received: from [10.1.196.93] (en101.cambridge.arm.com [10.1.196.93]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CA7883F575; Mon, 25 Mar 2019 03:59:36 -0700 (PDT) Subject: Re: [PATCH v6 04/10] arm64: Advertise mitigation of Spectre-v2, or lack thereof To: jeremy.linton@arm.com, linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com, will.deacon@arm.com, marc.zyngier@arm.com, dave.martin@arm.com, shankerd@codeaurora.org, julien.thierry@arm.com, mlangsdo@redhat.com, stefan.wahren@i2e.com, andre.przywara@arm.com, linux-kernel@vger.kernel.org, stefan.wahren@i2se.com References: <20190321230557.45107-1-jeremy.linton@arm.com> <20190321230557.45107-5-jeremy.linton@arm.com> From: Suzuki K Poulose Message-ID: <3a642196-4c6c-9efe-946b-9d6ecf33c9e3@arm.com> Date: Mon, 25 Mar 2019 10:59:34 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 In-Reply-To: <20190321230557.45107-5-jeremy.linton@arm.com> 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 21/03/2019 23:05, Jeremy Linton wrote: > From: Marc Zyngier > > We currently have a list of CPUs affected by Spectre-v2, for which > we check that the firmware implements ARCH_WORKAROUND_1. It turns > out that not all firmwares do implement the required mitigation, > and that we fail to let the user know about it. > > Instead, let's slightly revamp our checks, and rely on a whitelist > of cores that are known to be non-vulnerable, and let the user know > the status of the mitigation in the kernel log. > > Signed-off-by: Marc Zyngier > [This makes more sense in front of the sysfs patch] > [Pick pieces of that patch into this and move it earlier] > Signed-off-by: Jeremy Linton > Reviewed-by: Andre Przywara > Tested-by: Stefan Wahren > --- Reviewed-by: Suzuki K Poulose