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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 60B7DC19F2D for ; Tue, 9 Aug 2022 06:20:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236842AbiHIGU3 (ORCPT ); Tue, 9 Aug 2022 02:20:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36476 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236727AbiHIGU0 (ORCPT ); Tue, 9 Aug 2022 02:20:26 -0400 Received: from out30-54.freemail.mail.aliyun.com (out30-54.freemail.mail.aliyun.com [115.124.30.54]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0ECDB1EEC1 for ; Mon, 8 Aug 2022 23:20:24 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R661e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045170;MF=guorui.yu@linux.alibaba.com;NM=1;PH=DS;RN=20;SR=0;TI=SMTPD_---0VLommuG_1660026017; Received: from 30.227.65.6(mailfrom:GuoRui.Yu@linux.alibaba.com fp:SMTPD_---0VLommuG_1660026017) by smtp.aliyun-inc.com; Tue, 09 Aug 2022 14:20:18 +0800 Message-ID: Date: Tue, 9 Aug 2022 14:20:16 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 To: dave.hansen@intel.com Cc: ak@linux.intel.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, isaku.yamahata@gmail.com, jun.nakajima@intel.com, kai.huang@intel.com, khalid.elmously@canonical.com, kirill.shutemov@linux.intel.com, linux-kernel@vger.kernel.org, marcelo.cerri@canonical.com, mingo@redhat.com, philip.cox@canonical.com, sathyanarayanan.kuppuswamy@linux.intel.com, tglx@linutronix.de, tim.gardner@canonical.com, tony.luck@intel.com, wander@redhat.com, x86@kernel.org References: <7c09d15b-40bc-c6a0-3282-a94e9d9c36be@intel.com> Subject: Re: [PATCH v8 5/5] x86/tdx: Add Quote generation support From: Guorui Yu In-Reply-To: <7c09d15b-40bc-c6a0-3282-a94e9d9c36be@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org To my opinion, virtio-vsock is a wonderful way to achieve the comunication between the host and the guest under traditional scenario. But from secuirty perspective, virtio-vsock itself may involve too much of components, which may lead to considerable attack surfaces. In order for virtio to work properly, the guest must maintain several vrings placed in shared memory, which in turn depends on swiotlb in current codebase. As this flow is NOT designed for confidential scenario, there are some on-going/existing works on virtio hardening [1] [2] [3]. > Do we *REALLY* need specific driver functionality for this? For > instance, is there no existing virtio device that can send blobs back > and forth? And we may indeed have use cases where virtio is not used at all, such as when we consider Intel-TDX/AMD-SNP protected VMs as a SGX enclave replacement. In such use cases, end users may expect a smaller dependency on the GetQuote interface. It doesn't seem natural that the GetQuote interface cannot be used because virtio-vsock is disabled (via kernel compile options or the upcoming device-filter), since GetQuote doesn't inherently depend on it. Thanks, Guorui [1] https://lore.kernel.org/lkml/20210603004133.4079390-1-ak@linux.intel.com/ [2] https://lore.kernel.org/lkml/20211012065227.9953-1-jasowang@redhat.com/ [3] https://lore.kernel.org/linux-iommu/d2ae0b1d-332b-42a1-87bf-7da2b749cac2@sect.tu-berlin.de/