Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1752341AbeAJSHL (ORCPT <rfc822;ralf@linux-mips.org> + 1 other);
        Wed, 10 Jan 2018 13:07:11 -0500
Received: from Galois.linutronix.de ([146.0.238.70]:56589 "EHLO
        Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1751891AbeAJSHK (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Wed, 10 Jan 2018 13:07:10 -0500
Date: Wed, 10 Jan 2018 19:06:27 +0100 (CET)
From: Thomas Gleixner <tglx@linutronix.de>
To: Tom Lendacky <thomas.lendacky@amd.com>
cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
        tim.c.chen@linux.intel.com, gregkh@linux-foundation.org,
        hpa@zytor.com, mingo@kernel.org, dwmw@amazon.co.uk,
        luto@amacapital.net, riel@redhat.com, dave.hansen@intel.com,
        keescook@google.com, ak@linux.intel.com, pjt@google.com,
        torvalds@linux-foundation.org, jikos@kernel.org,
        linux-tip-commits@vger.kernel.org
Subject: Re: [tip:x86/pti] x86/spectre: Add boot time option to select Spectre
 v2 mitigation
In-Reply-To: <7689f631-7179-79f4-111b-418214432cc7@amd.com>
Message-ID: <alpine.DEB.2.20.1801101906080.1919@nanos>
References: <1515508997-6154-4-git-send-email-dwmw@amazon.co.uk> <tip-d569ded27d11bcb1643b14c54403910d9b3328b1@git.kernel.org> <7689f631-7179-79f4-111b-418214432cc7@amd.com>
User-Agent: Alpine 2.20 (DEB 67 2015-01-07)
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Return-Path: <linux-kernel-owner@vger.kernel.org>

On Wed, 10 Jan 2018, Tom Lendacky wrote:
> > +retpoline_auto:
> > +	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
> 
> Not specifying anything on the command line will get SPECTRE_V2_CMD_AUTO,
> so boot_cpu_has(X86_FEATURE_LFENCE_RDTSC) needs to be checked since it
> won't have been checked previously.

Dammit.