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 12F69C433EF for ; Thu, 21 Jul 2022 18:31:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229913AbiGUSbN (ORCPT ); Thu, 21 Jul 2022 14:31:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50102 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229498AbiGUSbL (ORCPT ); Thu, 21 Jul 2022 14:31:11 -0400 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E4E672559A for ; Thu, 21 Jul 2022 11:31:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1658428270; x=1689964270; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=W4/tIIdtERhphnO7fWOgUzVvIqF1v4fyTEzDJ1w8bGc=; b=H0igRBmaPEMArSCdvZSun+cmgb0jfQ1tayWIHeGU1rP0fOusfY2L44XO ZF5XGmVz2dhSeo5AeXqEW7xCeO14Xw5G764Yee5fT/MeoCddjPVJqCA0u /UZvr9oIDPDF9qEA0eFTC2RCV2A3N6yiltpobbU2Ug2EsYGAY0Wq1xpgq RstQjzUXB22J44RGOxbMF3x7yZBzthy9HieHQATr/IRH8giL5T3WgfDip Ev4dZJHnfzjO57TFe2sI8E82L16Y82/7E9pStYqmnPNvE3dEoI9/I3zDe /9qKnia1aitlh2rKedLPwSSB+hwKoAY5NqAFCzIDTCY1favaljAbZsybF g==; X-IronPort-AV: E=McAfee;i="6400,9594,10415"; a="284697925" X-IronPort-AV: E=Sophos;i="5.93,183,1654585200"; d="scan'208";a="284697925" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Jul 2022 11:31:10 -0700 X-IronPort-AV: E=Sophos;i="5.93,183,1654585200"; d="scan'208";a="598574968" Received: from sattaran-mobl1.amr.corp.intel.com (HELO [10.212.246.186]) ([10.212.246.186]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Jul 2022 11:31:10 -0700 Message-ID: <9a85546c-954d-446d-28d5-8a88be5a1ce3@linux.intel.com> Date: Thu, 21 Jul 2022 11:31:09 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Firefox/91.0 Thunderbird/91.11.0 Subject: Re: [PATCH v8 5/5] x86/tdx: Add Quote generation support Content-Language: en-US To: Dave Hansen , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org Cc: "H . Peter Anvin" , "Kirill A . Shutemov" , Tony Luck , Andi Kleen , Kai Huang , Wander Lairson Costa , Isaku Yamahata , 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> <214e24f0-5236-be8d-024a-da48737d854a@intel.com> From: Sathyanarayanan Kuppuswamy In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Dave, On 7/21/22 10:19 AM, Dave Hansen wrote: > How many bytes does the TDX module read from and write to the guest > physical address space? What are the absolute limits? What is the > minimum and the maximum that the kernel needs to handle? Minimum is 1K (equal to TDREPORT size, on input Quoting Enclave reads 1K TDREPORT data from GPA) Maximum size is not defined in the spec. I think for future compatibility, spec does not limit the quote size. For most cases, I think 8K should be big enough. -- Sathyanarayanan Kuppuswamy Linux Kernel Developer