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_PASS,URIBL_BLOCKED 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 4F19BC10F13 for ; Tue, 16 Apr 2019 07:53:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 17E0120868 for ; Tue, 16 Apr 2019 07:53:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555401219; bh=ONqeZcRHRT/O4g4lf7ZcpK42MxCIqizXMac+tt9gYaY=; h=Date:From:To:cc:Subject:In-Reply-To:References:List-ID:From; b=uAIwa56Mxhpv39LGoccmlmSWtyofEBz87tjBuswyD8JyNd8SR2osW22zFLYl1xACu iYeFAtYoRX6LnxMmj5dzsmq5VQmi7PyYTzGKKIS7yEnc9mBq80JjTiM5XS48JQaC+g TfGFGBKgT+TFqgHIgdXRZ6ZJlsb91vbZK5mO+1xg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728652AbfDPHxh (ORCPT ); Tue, 16 Apr 2019 03:53:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:60156 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726837AbfDPHxh (ORCPT ); Tue, 16 Apr 2019 03:53:37 -0400 Received: from pobox.suse.cz (prg-ext-pat.suse.com [213.151.95.130]) (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 7A70F2073F; Tue, 16 Apr 2019 07:53:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555401216; bh=ONqeZcRHRT/O4g4lf7ZcpK42MxCIqizXMac+tt9gYaY=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=FBg4Q0pIZL9TzwGBeYNIsctEvSg9Xx1zDVoIJ8BBPSImdhijx5iyU5zfnuznvWNaW GgsIOlz1u2GnfLehgDY/RZ4KUFg838OqNk+mpm0X3nkfHreLYfzrN4t//RYhmSTgIi yM2b4pHeeElMHPiKlio78LPNCpf28uUgF10x+Ogs= Date: Tue, 16 Apr 2019 09:53:29 +0200 (CEST) From: Jiri Kosina To: Josh Poimboeuf cc: linux-kernel@vger.kernel.org, x86@kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , Andy Lutomirski , Peter Zijlstra , Waiman Long , Andrea Arcangeli , Jon Masters , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , linuxppc-dev@lists.ozlabs.org, Martin Schwidefsky , Heiko Carstens , linux-s390@vger.kernel.org, Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-arch@vger.kernel.org, Greg Kroah-Hartman , Tyler Hicks , Linus Torvalds , Randy Dunlap , Steven Price , Phil Auld Subject: Re: [PATCH v2 0/5] cpu/speculation: Add 'mitigations=' cmdline option In-Reply-To: Message-ID: References: User-Agent: Alpine 2.21 (LSU 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 12 Apr 2019, Josh Poimboeuf wrote: > v2: > - docs improvements: [Randy, Michael] > - Rename to "mitigations=" [Michael] > - Add cpu_mitigations_off() function wrapper [Michael] > - x86: Simplify logic [Boris] > - powerpc: Fix no_rfi_flush checking bug (use '&&' instead of '||') > - arm64: Rebase onto Jeremy Linton's v7 patches [Will] > - arm64: "kpti command line option" [Steve P] > - arm64: Add nospectre_v2 support > > ----------- > > Keeping track of the number of mitigations for all the CPU speculation > bugs has become overwhelming for many users. It's getting more and more > complicated to decide which mitigations are needed for a given > architecture. Complicating matters is the fact that each arch tends to > have its own custom way to mitigate the same vulnerability. > > Most users fall into a few basic categories: > > a) they want all mitigations off; > > b) they want all reasonable mitigations on, with SMT enabled even if > it's vulnerable; or > > c) they want all reasonable mitigations on, with SMT disabled if > vulnerable. > > Define a set of curated, arch-independent options, each of which is an > aggregation of existing options: > > - mitigations=off: Disable all mitigations. > > - mitigations=auto: [default] Enable all the default mitigations, but > leave SMT enabled, even if it's vulnerable. > > - mitigations=auto,nosmt: Enable all the default mitigations, disabling > SMT if needed by a mitigation. > > Josh Poimboeuf (5): > cpu/speculation: Add 'mitigations=' cmdline option > x86/speculation: Support 'mitigations=' cmdline option > powerpc/speculation: Support 'mitigations=' cmdline option > s390/speculation: Support 'mitigations=' cmdline option > arm64/speculation: Support 'mitigations=' cmdline option Tested-by: Jiri Kosina (on x86) Reviewed-by: Jiri Kosina Thanks, -- Jiri Kosina SUSE Labs