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 A730EC433EF for ; Fri, 22 Jul 2022 19:13:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235031AbiGVTNp (ORCPT ); Fri, 22 Jul 2022 15:13:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49276 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231304AbiGVTNn (ORCPT ); Fri, 22 Jul 2022 15:13:43 -0400 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B5E898E6D3 for ; Fri, 22 Jul 2022 12:13:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1658517222; x=1690053222; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=YoJQ8g3alU7LX3m6yJN6hMCGycY7i0kWZrAaTQOKp5I=; b=ZyF/9NosOSo5Se8zTWt9L2nrNOoWjnt8q/yuv9Cq46McO7UwKmyO6sAT 0oFAC3u0PeNmfJ5+vYBFoJceWmJjq8y9+xId0Lmj48ZlwBGyEMD2N4DVd 3UoaEWlGWL80hYOI3jwkbDnKVLUPy2kFI4jYPK36ExWzgxmYGOlPlCfnE 8xx6jhoMsJ5vPRT8MzVYnr97i/K0h0uH2UlWF3O2RlDy+DbEE9bZQKFtS G+W0Re+edhTip8vjHgOVSPQR+hEacfhLrm3uv4MPvwO8TAlDrNpsFCxfd gJ9PO9Bjaxr7VaDqVdapaNhJ9ZFh78fRRvHpsUFlHu6HX7b5j9p2EvqCW w==; X-IronPort-AV: E=McAfee;i="6400,9594,10416"; a="349088845" X-IronPort-AV: E=Sophos;i="5.93,186,1654585200"; d="scan'208";a="349088845" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Jul 2022 12:13:25 -0700 X-IronPort-AV: E=Sophos;i="5.93,186,1654585200"; d="scan'208";a="926157886" Received: from jnoah-mobl.amr.corp.intel.com (HELO [10.209.71.211]) ([10.209.71.211]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Jul 2022 12:13:24 -0700 Message-ID: <18578c5a-7a35-ab20-467c-80141b0410a8@intel.com> Date: Fri, 22 Jul 2022 12:13:23 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: Re: [PATCH v8 5/5] x86/tdx: Add Quote generation support Content-Language: en-US To: Isaku Yamahata Cc: Kuppuswamy Sathyanarayanan , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H . Peter Anvin" , "Kirill A . Shutemov" , Tony Luck , Andi Kleen , Kai Huang , Wander Lairson Costa , marcelo.cerri@canonical.com, tim.gardner@canonical.com, khalid.elmously@canonical.com, philip.cox@canonical.com, linux-kernel@vger.kernel.org References: <20220609025220.2615197-1-sathyanarayanan.kuppuswamy@linux.intel.com> <20220609025220.2615197-6-sathyanarayanan.kuppuswamy@linux.intel.com> <403cfccb-7fff-ab0b-8ebd-e5b04e631571@intel.com> <20220722190524.GA3299911@ls.amr.corp.intel.com> From: Dave Hansen In-Reply-To: <20220722190524.GA3299911@ls.amr.corp.intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/22/22 12:05, Isaku Yamahata wrote: >> So, the quote portion of this is basically a bidirectional blob sender. >> It's to send a blob between guest userspace to host userspace. >> >> Do we *REALLY* need specific driver functionality for this? For >> instance, is there no existing virtio device that can send blobs back >> and forth? > It's virtio-vsock. If virtio-vsock is available, the communication works. > However, some users would like to disable virtio-vsock on their environment for > some reasons. Even virtio at all. Especially for confidential computing use > case. It's their choice. It can't be assumed that virtio is available. > > The goal is VMM-agnostic (but TDX-specific) interface for that. You're basically saying that every confidential computing technology should have its own host user <-> guest kernel <-> guest user ABI. That's insanity. If we do this, we need *one* interface that says "talk to the hypervisor" that's common for all hypervisors and hardware vendors, or at least more than *one*. We don't need a way to talk to hypervisors for Intel systems and another for AMD and yet another on whatever.