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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_NEOMUTT 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 2BA9FC4360F for ; Fri, 5 Apr 2019 15:30:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0320121872 for ; Fri, 5 Apr 2019 15:30:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731298AbfDEPa5 (ORCPT ); Fri, 5 Apr 2019 11:30:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35268 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726291AbfDEPa5 (ORCPT ); Fri, 5 Apr 2019 11:30:57 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D00553082AFD; Fri, 5 Apr 2019 15:30:56 +0000 (UTC) Received: from treble (ovpn-123-87.rdu2.redhat.com [10.10.123.87]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CA39A60BFB; Fri, 5 Apr 2019 15:30:50 +0000 (UTC) Date: Fri, 5 Apr 2019 10:30:48 -0500 From: Josh Poimboeuf To: Randy Dunlap Cc: Borislav Petkov , linux-kernel@vger.kernel.org, x86@kernel.org, Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Andy Lutomirski , Peter Zijlstra , Jiri Kosina , 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 Subject: Re: [PATCH RFC 2/5] x86/speculation: Add support for 'cpu_spec_mitigations=' cmdline options Message-ID: <20190405153048.knaizips2n27fwtx@treble> References: <78c63cb08f36f55407f534d49cc2543079e44dbb.1554396090.git.jpoimboe@redhat.com> <20190405135712.GF23348@zn.tnic> <5ccc7515-33e6-b726-833e-9553ab0f4c6a@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <5ccc7515-33e6-b726-833e-9553ab0f4c6a@infradead.org> User-Agent: NeoMutt/20180716 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.45]); Fri, 05 Apr 2019 15:30:57 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 05, 2019 at 08:18:09AM -0700, Randy Dunlap wrote: > On 4/5/19 6:57 AM, Borislav Petkov wrote: > > On Thu, Apr 04, 2019 at 11:44:12AM -0500, Josh Poimboeuf wrote: > >> Configure x86 runtime CPU speculation bug mitigations in accordance with > >> the 'cpu_spec_mitigations=' cmdline options. This affects Meltdown, > >> Spectre v2, Speculative Store Bypass, and L1TF. > >> > >> The default behavior is unchanged. > >> > >> Signed-off-by: Josh Poimboeuf > >> --- > >> .../admin-guide/kernel-parameters.txt | 15 +++++++++ > >> arch/x86/include/asm/processor.h | 1 + > >> arch/x86/kernel/cpu/bugs.c | 32 ++++++++++++++++--- > >> arch/x86/kvm/vmx/vmx.c | 2 ++ > >> arch/x86/mm/pti.c | 4 ++- > >> 5 files changed, 49 insertions(+), 5 deletions(-) > >> > >> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > >> index ac42e510bd6e..29dc03971630 100644 > >> --- a/Documentation/admin-guide/kernel-parameters.txt > >> +++ b/Documentation/admin-guide/kernel-parameters.txt > >> @@ -2552,6 +2552,11 @@ > >> > >> off > >> Disable all speculative CPU mitigations. > >> + Equivalent to: nopti [x86] > >> + nospectre_v2 [x86] > >> + spectre_v2_user=off [x86] > >> + spec_store_bypass_disable=off [x86] > >> + l1tf=off [x86] > >> > >> auto (default) > >> Mitigate all speculative CPU vulnerabilities, > >> @@ -2560,12 +2565,22 @@ > >> surprised by SMT getting disabled across kernel > >> upgrades, or who have other ways of avoiding > >> SMT-based attacks. > >> + Equivalent to: pti=auto [x86] > >> + spectre_v2=auto [x86] > >> + spectre_v2_user=auto [x86] > >> + spec_store_bypass_disable=auto [x86] > >> + l1tf=flush [x86] > >> > >> auto,nosmt > >> Mitigate all speculative CPU vulnerabilities, > >> disabling SMT if needed. This is for users who > >> always want to be fully mitigated, even if it > >> means losing SMT. > >> + Equivalent to: pti=auto [x86] > >> + spectre_v2=auto [x86] > >> + spectre_v2_user=auto [x86] > >> + spec_store_bypass_disable=auto [x86] > >> + l1tf=flush,nosmt [x86] > >> > >> mminit_loglevel= > >> [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this > > > > Yap, those sets look ok. > > nit: s/x86/X86/g > according to Documentation/admin-guide/kernel-parameters.rst Ah, I didn't realize I was conforming to a standard. I will update the other arch strings as well. Thanks. -- Josh