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 7C870C433F5 for ; Tue, 19 Apr 2022 22:22:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357768AbiDSWYv (ORCPT ); Tue, 19 Apr 2022 18:24:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52240 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229599AbiDSWYq (ORCPT ); Tue, 19 Apr 2022 18:24:46 -0400 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0D39722BE7; Tue, 19 Apr 2022 15:22:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1650406922; x=1681942922; h=message-id:subject:from:to:cc:date:in-reply-to: references:mime-version:content-transfer-encoding; bh=7FPoGNOFLlOXDs/xu3hONgTHzwKlS/vbPKmpCE0gDjo=; b=HnWtQxI0xa8kEbGSLMjLYMwO1/Sk+XoD9m9VfiV0dQH+gUndEVooD5dG KTI1ony/8LY7K1OEuaVUIxukdU/I3PuFDB2puJ0Ij2rDahI0W9a0nlL/L jnoV4F9D/taV9eRoDbPBTHAvQBRMtcvihlMX2Xi1TeH+olCWEqYW1BADj FUYnRS+L4OX0abGTn483wKveHwF2DM+P6KXNMReoEZJ8X+b9bYGWLHQ1b 5uU9tHibQ9mWepblGOjpsbZo0QwmW6+zvQYPA3+8zW8bnxj97iUHEmZCy qyCnbnOOPuqUxQluq5hxVwMebIzYmt2Kvq2QvQiURxloWNJC+GNwk1NIJ g==; X-IronPort-AV: E=McAfee;i="6400,9594,10322"; a="264058068" X-IronPort-AV: E=Sophos;i="5.90,273,1643702400"; d="scan'208";a="264058068" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Apr 2022 15:22:01 -0700 X-IronPort-AV: E=Sophos;i="5.90,273,1643702400"; d="scan'208";a="554918565" Received: from asaini1-mobl1.amr.corp.intel.com (HELO khuang2-desk.gar.corp.intel.com) ([10.254.58.15]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Apr 2022 15:21:57 -0700 Message-ID: Subject: Re: [PATCH v3 4/4] platform/x86: intel_tdx_attest: Add TDX Guest attestation interface driver From: Kai Huang To: Dave Hansen , Kuppuswamy Sathyanarayanan , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, Hans de Goede , Mark Gross Cc: "H . Peter Anvin" , "Kirill A . Shutemov" , Tony Luck , Andi Kleen , linux-kernel@vger.kernel.org, platform-driver-x86@vger.kernel.org Date: Wed, 20 Apr 2022 10:21:55 +1200 In-Reply-To: <975b5050-2108-9ace-cc71-46f17db0a731@intel.com> References: <20220415220109.282834-1-sathyanarayanan.kuppuswamy@linux.intel.com> <20220415220109.282834-5-sathyanarayanan.kuppuswamy@linux.intel.com> <975b5050-2108-9ace-cc71-46f17db0a731@intel.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.42.4 (3.42.4-1.fc35) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2022-04-19 at 07:13 -0700, Dave Hansen wrote: > On 4/19/22 00:47, Kai Huang wrote: > > > From security's perspective, attestation is an essential part of TDX. That > > being said, w/o attestation support in TD guest, I guess nobody will seriously > > use TD guest. > > Are you saying you can't think of a single threat model where there's a > benefit to running a TDX guest without attestation? Will TDX only be > used in environments where secrets are provisioned to guests on the > basis of attestation? > > > I don't think anyone should provision secret to a TD before it get attested that it is a genuine TD that he/she expected. If someone does that, he/she takes the risk of losing the secret. Of course if someone just want to try a TD then w/o attestation is totally fine. -- Thanks, -Kai