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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 CCC8ACA9EAF for ; Sun, 27 Oct 2019 11:00:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 969D121726 for ; Sun, 27 Oct 2019 11:00:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572174024; bh=Jmt2B0VEl/FUjM+MgzpTzTtF3WYLk8v8TfnsbPH95BE=; h=Date:In-Reply-To:References:Subject:To:CC:From:List-ID:From; b=0ZuUHeOs4uZ6y3znAxCCrZklIT4twHSYDeyS6wvHsz/yebG4+TsFIsulqgTek4ZjF J8t8McZpQHzI6Nx7gqPxELtOY3+4al1j0MI2Xe+I9GhwN0IChfmUlbMRc5pNSqcNSO /7p0t9gYb5iKXg8AKehKDMt59CY2hxTj6FILPa04= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726734AbfJ0LAX (ORCPT ); Sun, 27 Oct 2019 07:00:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:45732 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726661AbfJ0LAX (ORCPT ); Sun, 27 Oct 2019 07:00:23 -0400 Received: from [10.173.153.26] (unknown [2.55.42.38]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6F46D214AF; Sun, 27 Oct 2019 11:00:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572174022; bh=Jmt2B0VEl/FUjM+MgzpTzTtF3WYLk8v8TfnsbPH95BE=; h=Date:In-Reply-To:References:Subject:To:CC:From:From; b=nWmDdz95jS72TenFW6vwu5hnpkWGaIk+42GN2FxxDR78HF8zBHoIhwHWcd2Rwlzhz BPaAzQljyMUopkP2ab89nUBAsWWGu6p1Oluy9j+CscUuN7lszAK4lXsB7HKKXgQ3LN biHkcQoaYhqZmf4mRHOemJcXCiJq/wuyvnKN1xoY= Date: Sun, 27 Oct 2019 13:00:13 +0200 User-Agent: K-9 Mail for Android In-Reply-To: <87d0eieb0i.fsf@mid.deneb.enyo.de> References: <1572171452-7958-1-git-send-email-rppt@kernel.org> <87d0eieb0i.fsf@mid.deneb.enyo.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [PATCH RFC] mm: add MAP_EXCLUSIVE to create exclusive user mappings To: Florian Weimer CC: linux-kernel@vger.kernel.org, Alexey Dobriyan , Andrew Morton , Andy Lutomirski , Arnd Bergmann , Borislav Petkov , Dave Hansen , James Bottomley , Peter Zijlstra , Steven Rostedt , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , linux-api@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, Mike Rapoport From: Mike Rapoport Message-ID: <385EB6D4-A1B0-4617-B256-181AA1C3BDE3@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On October 27, 2019 12:30:21 PM GMT+02:00, Florian Weimer wrote: >* Mike Rapoport: > >> The patch below aims to allow applications to create mappins that >have >> pages visible only to the owning process=2E Such mappings could be used >to >> store secrets so that these secrets are not visible neither to other >> processes nor to the kernel=2E > >How is this expected to interact with CRIU? CRIU dumps the memory contents using a parasite code from inside the dumpe= e address space, so it would work the same way as for the other mappings=2E= Of course, at the restore time the exclusive mapping should be recreated w= ith the appropriate flags=2E >> I've only tested the basic functionality, the changes should be >verified >> against THP/migration/compaction=2E Yet, I'd appreciate early feedback= =2E > >What are the expected semantics for VM migration? Should it fail? I don't quite follow=2E If qemu would use such mappings it would be able t= o transfer them during live migration=2E --=20 Sincerely yours, Mike