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=-6.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 C8AABC432BE for ; Tue, 31 Aug 2021 20:39:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B58D261041 for ; Tue, 31 Aug 2021 20:39:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241199AbhHaUkk (ORCPT ); Tue, 31 Aug 2021 16:40:40 -0400 Received: from mga14.intel.com ([192.55.52.115]:37312 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241119AbhHaUkd (ORCPT ); Tue, 31 Aug 2021 16:40:33 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10093"; a="218283982" X-IronPort-AV: E=Sophos;i="5.84,367,1620716400"; d="scan'208";a="218283982" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Aug 2021 13:39:36 -0700 X-IronPort-AV: E=Sophos;i="5.84,367,1620716400"; d="scan'208";a="687867566" Received: from akleen-mobl1.amr.corp.intel.com (HELO [10.209.121.250]) ([10.209.121.250]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Aug 2021 13:39:33 -0700 Subject: Re: [RFC] KVM: mm: fd-based approach for supporting KVM guest private memory To: David Hildenbrand , Yu Zhang Cc: Sean Christopherson , Paolo Bonzini , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Borislav Petkov , Andy Lutomirski , Andrew Morton , Joerg Roedel , David Rientjes , Vlastimil Babka , Tom Lendacky , Thomas Gleixner , Peter Zijlstra , Ingo Molnar , Varad Gautam , Dario Faggioli , x86@kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev, "Kirill A . Shutemov" , "Kirill A . Shutemov" , Kuppuswamy Sathyanarayanan , Dave Hansen References: <20210824005248.200037-1-seanjc@google.com> <307d385a-a263-276f-28eb-4bc8dd287e32@redhat.com> <20210827023150.jotwvom7mlsawjh4@linux.intel.com> <243bc6a3-b43b-cd18-9cbb-1f42a5de802f@redhat.com> <765e9bbe-2df5-3dcc-9329-347770dc091d@linux.intel.com> <4677f310-5987-0c13-5caf-fd3b625b4344@redhat.com> From: Andi Kleen Message-ID: Date: Tue, 31 Aug 2021 13:39:31 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <4677f310-5987-0c13-5caf-fd3b625b4344@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/31/2021 1:15 PM, David Hildenbrand wrote: > On 31.08.21 22:01, Andi Kleen wrote: >> >>>> Thanks a lot for this summary. A question about the requirement: do >>>> we or >>>> do we not have plan to support assigned device to the protected VM? >>> >>> Good question, I assume that is stuff for the far far future. >> >> It is in principle possible with the current TDX, but not secure. But >> someone might decide to do it. So it would be good to have basic support >> at least. > > Can you elaborate the "not secure" part? Do you mean, making the > device only access "shared" memory, not secure/encrypted/whatsoever? Yes that's right. It can only access shared areas. -Andi From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 961DC3FC3 for ; Tue, 31 Aug 2021 20:49:17 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10093"; a="240827571" X-IronPort-AV: E=Sophos;i="5.84,367,1620716400"; d="scan'208";a="240827571" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Aug 2021 13:39:36 -0700 X-IronPort-AV: E=Sophos;i="5.84,367,1620716400"; d="scan'208";a="687867566" Received: from akleen-mobl1.amr.corp.intel.com (HELO [10.209.121.250]) ([10.209.121.250]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Aug 2021 13:39:33 -0700 Subject: Re: [RFC] KVM: mm: fd-based approach for supporting KVM guest private memory To: David Hildenbrand , Yu Zhang Cc: Sean Christopherson , Paolo Bonzini , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Borislav Petkov , Andy Lutomirski , Andrew Morton , Joerg Roedel , David Rientjes , Vlastimil Babka , Tom Lendacky , Thomas Gleixner , Peter Zijlstra , Ingo Molnar , Varad Gautam , Dario Faggioli , x86@kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev, "Kirill A . Shutemov" , "Kirill A . Shutemov" , Kuppuswamy Sathyanarayanan , Dave Hansen References: <20210824005248.200037-1-seanjc@google.com> <307d385a-a263-276f-28eb-4bc8dd287e32@redhat.com> <20210827023150.jotwvom7mlsawjh4@linux.intel.com> <243bc6a3-b43b-cd18-9cbb-1f42a5de802f@redhat.com> <765e9bbe-2df5-3dcc-9329-347770dc091d@linux.intel.com> <4677f310-5987-0c13-5caf-fd3b625b4344@redhat.com> From: Andi Kleen Message-ID: Date: Tue, 31 Aug 2021 13:39:31 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <4677f310-5987-0c13-5caf-fd3b625b4344@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US On 8/31/2021 1:15 PM, David Hildenbrand wrote: > On 31.08.21 22:01, Andi Kleen wrote: >> >>>> Thanks a lot for this summary. A question about the requirement: do >>>> we or >>>> do we not have plan to support assigned device to the protected VM? >>> >>> Good question, I assume that is stuff for the far far future. >> >> It is in principle possible with the current TDX, but not secure. But >> someone might decide to do it. So it would be good to have basic support >> at least. > > Can you elaborate the "not secure" part? Do you mean, making the > device only access "shared" memory, not secure/encrypted/whatsoever? Yes that's right. It can only access shared areas. -Andi