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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 73103C432C0 for ; Tue, 26 Nov 2019 20:50:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4D3E82080F for ; Tue, 26 Nov 2019 20:50:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726232AbfKZUua (ORCPT ); Tue, 26 Nov 2019 15:50:30 -0500 Received: from mga03.intel.com ([134.134.136.65]:30537 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725970AbfKZUu3 (ORCPT ); Tue, 26 Nov 2019 15:50:29 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Nov 2019 12:50:28 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,246,1571727600"; d="scan'208";a="260799765" Received: from tassilo.jf.intel.com (HELO tassilo.localdomain) ([10.7.201.21]) by FMSMGA003.fm.intel.com with ESMTP; 26 Nov 2019 12:50:28 -0800 Received: by tassilo.localdomain (Postfix, from userid 1000) id 29016300B64; Tue, 26 Nov 2019 12:50:28 -0800 (PST) Date: Tue, 26 Nov 2019 12:50:28 -0800 From: Andi Kleen To: Borislav Petkov Cc: x86-ml , lkml Subject: Re: [RFC PATCH] x86: Filter MSR writes from luserspace Message-ID: <20191126205028.GJ84886@tassilo.jf.intel.com> References: <20191126112234.GA22393@zn.tnic> <87zhgie6nl.fsf@linux.intel.com> <20191126203336.GF31379@zn.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191126203336.GF31379@zn.tnic> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 26, 2019 at 09:33:36PM +0100, Borislav Petkov wrote: > On Tue, Nov 26, 2019 at 12:15:10PM -0800, Andi Kleen wrote: > > This will break a bazillion of tools that rely on programing many of > > those MSRs from user space. > > Userspace has no deal to poke into random MSRs. End of story. You'll almost certainly violate Linus' golden rule of application compatibility and the whole thing will be reverted in the end. -Andi