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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 8E50AC32771 for ; Wed, 15 Jan 2020 22:19:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 63F9A2187F for ; Wed, 15 Jan 2020 22:19:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730592AbgAOWTz (ORCPT ); Wed, 15 Jan 2020 17:19:55 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:49401 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728899AbgAOWTz (ORCPT ); Wed, 15 Jan 2020 17:19:55 -0500 Received: from p5b06da22.dip0.t-ipconnect.de ([91.6.218.34] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1irr0v-0002IC-V0; Wed, 15 Jan 2020 23:19:50 +0100 Received: by nanos.tec.linutronix.de (Postfix, from userid 1000) id 0D22D101228; Wed, 15 Jan 2020 23:19:49 +0100 (CET) From: Thomas Gleixner To: Tony W Wang-oc , mingo@redhat.com, bp@alien8.de, hpa@zytor.com, x86@kernel.org, linux-kernel@vger.kernel.org Cc: DavidWang@zhaoxin.com, CooperYan@zhaoxin.com, QiyuanWang@zhaoxin.com, HerryYang@zhaoxin.com Subject: Re: [PATCH] x86/cpu: clear X86_BUG_SPECTRE_V2 on Zhaoxin family 7 CPUs In-Reply-To: <1579075500-7065-1-git-send-email-TonyWWang-oc@zhaoxin.com> References: <1579075500-7065-1-git-send-email-TonyWWang-oc@zhaoxin.com> Date: Wed, 15 Jan 2020 23:19:49 +0100 Message-ID: <87h80wxsze.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Tony W Wang-oc writes: > These CPUs are not affected by spectre_v2, so clear spectre_v2 bug flag > in their specific initialization code. > > if (cpu_has(c, X86_FEATURE_VMX)) > centaur_detect_vmx_virtcap(c); > + > + if (c->x86 == 7) { > + setup_clear_cpu_cap(X86_BUG_SPECTRE_V2); > + clear_bit(X86_BUG_SPECTRE_V2, (unsigned long *)cpu_caps_set); No. Please use cpu_vuln_whitelist. It exists for exactly this purpose. You just need to extend it with a NO_SPECTRE_V2 bit. Thanks, tglx