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=-8.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 7218AC433E2 for ; Fri, 4 Sep 2020 20:09:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2998C2084D for ; Fri, 4 Sep 2020 20:09:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="SkHB3LF1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726833AbgIDUJR (ORCPT ); Fri, 4 Sep 2020 16:09:17 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:42875 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726618AbgIDUJQ (ORCPT ); Fri, 4 Sep 2020 16:09:16 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599250155; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=YtjkCDBznio4EFWycuRl0XTCwzQwRh7Zk8qEDyaA+R8=; b=SkHB3LF1u3YG69b65ZrXrV5o+cXjx88x1KeHVSxn+qrqrrn9ZCO8BbeV1oYV3Quaj2JVHZ K8RdZtiT3CZXfIO7stHuwW+UfF40LeBIOQBFDtsMra2CxHUeQ9qCZThSYrIkIenSrUm3Hr wM+w2EWSSAooLWE+wBwRSLwyVLs6Pn8= Received: from mail-ej1-f70.google.com (mail-ej1-f70.google.com [209.85.218.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-289-AH7wONrrPxObzaVD5RxhkA-1; Fri, 04 Sep 2020 16:09:14 -0400 X-MC-Unique: AH7wONrrPxObzaVD5RxhkA-1 Received: by mail-ej1-f70.google.com with SMTP id lx11so1197692ejb.19 for ; Fri, 04 Sep 2020 13:09:13 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=YtjkCDBznio4EFWycuRl0XTCwzQwRh7Zk8qEDyaA+R8=; b=Y812j6R6HbNAuDcTG8u/t+Mc/+Typ+wQVJ0ZFpV+ZbZYXLkRB1xsfvhHJXnMf4ofdv skluo2LmZbv7OPhGkdfgrp8KTZI945F29cM4Yzyx1m1NL4flH5B2JOz3pigoY4Wu1D/+ UDPRq6ZIOOSKpDL8e6pufq6dTCBzWIn2MoA52AA70QN9ZCq6/SN02Gf9ll4hDuB5A5au h905RzQa0Im5UhxDTW6hV0zbkb2Dfke6pa+gH9LA3WZfdDRhEJ7CA+18lePZYJ9aJuP2 ZlFX9vQY3QjB3xq4Bj7dtnBZjX0R3wwM3A8Bl4wh0du2YMz9JqLbQgqBl6Rt7QpHuPGu SJhw== X-Gm-Message-State: AOAM5330VRVeBvdjhUwmFXUKIIqtx5BzsFYyxqC8stxrIm99qGInnrFj bv2E0HU6PbXEi2Q88lxMUxWD/tzrmYAK+yoR9xeCJIv25rUgRf/eDi0LoghzlWkSENEpKxqMMnY W1xTYbXFlKEzZIy9QftPQ X-Received: by 2002:a05:6402:1697:: with SMTP id a23mr10639654edv.195.1599250152834; Fri, 04 Sep 2020 13:09:12 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyX4Xhh11LgQlC31ujeG/EeQSnZyvInjG7xGIKM954pWhZp/ItPYfvo3YIfvnGUyMHrRxxzsg== X-Received: by 2002:a05:6402:1697:: with SMTP id a23mr10639629edv.195.1599250152631; Fri, 04 Sep 2020 13:09:12 -0700 (PDT) Received: from [192.168.10.150] ([93.56.170.5]) by smtp.gmail.com with ESMTPSA id bq24sm7048032ejb.27.2020.09.04.13.09.11 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 04 Sep 2020 13:09:11 -0700 (PDT) Subject: Re: [RESEND RFC PATCH 0/5] Remote mapping To: Andy Lutomirski , =?UTF-8?Q?Adalbert_Laz=c4=83r?= Cc: Linux-MM , Linux API , Andrew Morton , Alexander Graf , Stefan Hajnoczi , Jerome Glisse , =?UTF-8?Q?Mihai_Don=c8=9bu?= , Mircea Cirjaliu , Arnd Bergmann , Sargun Dhillon , Aleksa Sarai , Oleg Nesterov , Jann Horn , Kees Cook , Matthew Wilcox , Christian Brauner References: <20200904113116.20648-1-alazar@bitdefender.com> From: Paolo Bonzini Message-ID: Date: Fri, 4 Sep 2020 22:09:10 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-api-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On 04/09/20 21:39, Andy Lutomirski wrote: > I'm a little concerned that it's actually too clever and that maybe a > more straightforward solution should be investigated. I personally > rather dislike the KVM model in which the guest address space mirrors > the host (QEMU) address space rather than being its own thing. In > particular, the current model means that extra-special-strange > mappings like SEV-encrypted memory are required to be present in the > QEMU page tables in order for the guest to see them. > > (If I had noticed that last bit before it went upstream, I would have > NAKked it. I would still like to see it deprecated and ideally > eventually removed from the kernel. We have absolutely no business > creating incoherent mappings like this.) NACK first and ask second, right Andy? I see that nothing has changed since Alan Cox left Linux. Paolo