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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 A0A01C742D7 for ; Fri, 12 Jul 2019 19:06:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 788C3205C9 for ; Fri, 12 Jul 2019 19:06:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="RXHwLzeN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727261AbfGLTGu (ORCPT ); Fri, 12 Jul 2019 15:06:50 -0400 Received: from merlin.infradead.org ([205.233.59.134]:36680 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727125AbfGLTGu (ORCPT ); Fri, 12 Jul 2019 15:06:50 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=UqgOWolirnCBEsyXVWQ2fOdoQVQ8hvpvnXJbQKMux3o=; b=RXHwLzeNIqmDjrorcLSQiAkd/ MUyTNzpAtlmP3XOZPMG/9cuvZT3fk71qTAQkMBMu8DBb1GOL8ivodXsj9Pt8IiM/kZ96KvDpTZjwz 17r4zad9PKi2F9zqIK6ucOLmVegd/xcPRvcqF20wupKYw+jZXH1ZmOIXT8XEVkMMIaJ9aYLBm8DHd tM4G+AW5wJjB9MjVM9GB3ZJ7WHHq0ew69CWEi8qFGPNUYHfBb7crHR1YOovT0vXC2Tn+lFUpMKhTF P6ee4Qt7cVbAz+2p3WYU2GNhlt9XGIdlP2tdn7gLJH2PcRy4OrhWuAKvM3WgUGF/AZPd0bcmRI52p pvWDraWCQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1hm0sB-0000J7-4g; Fri, 12 Jul 2019 19:06:23 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 1D164201D16FC; Fri, 12 Jul 2019 21:06:20 +0200 (CEST) Date: Fri, 12 Jul 2019 21:06:20 +0200 From: Peter Zijlstra To: Alexandre Chartre Cc: Thomas Gleixner , Dave Hansen , pbonzini@redhat.com, rkrcmar@redhat.com, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, kvm@vger.kernel.org, x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, konrad.wilk@oracle.com, jan.setjeeilers@oracle.com, liran.alon@oracle.com, jwadams@google.com, graf@amazon.de, rppt@linux.vnet.ibm.com, Paul Turner Subject: Re: [RFC v2 00/27] Kernel Address Space Isolation Message-ID: <20190712190620.GX3419@hirez.programming.kicks-ass.net> References: <1562855138-19507-1-git-send-email-alexandre.chartre@oracle.com> <5cab2a0e-1034-8748-fcbe-a17cf4fa2cd4@intel.com> <61d5851e-a8bf-e25c-e673-b71c8b83042c@oracle.com> <20190712125059.GP3419@hirez.programming.kicks-ass.net> <3ca70237-bf8e-57d9-bed5-bc2329d17177@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3ca70237-bf8e-57d9-bed5-bc2329d17177@oracle.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, Jul 12, 2019 at 06:37:47PM +0200, Alexandre Chartre wrote: > On 7/12/19 5:16 PM, Thomas Gleixner wrote: > > Right. If we decide to expose more parts of the kernel mappings then that's > > just adding more stuff to the existing user (PTI) map mechanics. > > If we expose more parts of the kernel mapping by adding them to the existing > user (PTI) map, then we only control the mapping of kernel sensitive data but > we don't control user mapping (with ASI, we exclude all user mappings). > > How would you control the mapping of userland sensitive data and exclude them > from the user map? Would you have the application explicitly identify sensitive > data (like Andy suggested with a /dev/xpfo device)? To what purpose do you want to exclude userspace from the kernel mapping; that is, what are you mitigating against with that?