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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A96DBC433F5 for ; Thu, 31 Mar 2022 14:53:10 +0000 (UTC) Received: from localhost ([::1]:35628 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nZwAf-0000hA-JX for qemu-devel@archiver.kernel.org; Thu, 31 Mar 2022 10:53:09 -0400 Received: from eggs.gnu.org ([209.51.188.92]:47094) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nZw8n-00070S-8w for qemu-devel@nongnu.org; Thu, 31 Mar 2022 10:51:13 -0400 Received: from mga17.intel.com ([192.55.52.151]:4153) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nZw8j-0005z3-52 for qemu-devel@nongnu.org; Thu, 31 Mar 2022 10:51:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1648738269; x=1680274269; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=IdPVgYv7jMZxTmW8cgKoipO58BY+gpsYPjK9ZurKhEw=; b=AGsbJW1o19Fk9j3bP1jpjvt8OjpoAfpvSL89DKfJkiTyWkrXKNfufGRN bwhPoTUboP7f+QxvtE9v8w5LemkBINiNytyeWQBZK3boSfsn9eC+M7Z1I jtr0LtZlzpf4vr25PC7jE/MUpJvbe1vTI3kYfVuEXm5V1Edtrz27xKTvK bsmnuSkudaCkOZsSG6NSAKRlR94GYMluPjxYKvt0cuBAIliilzTVooomo qdFON9Wtpx+P+IvA3LUSdubAZpIABoL12oo6BqGZtPA7heXyr0/0kEa6z 4evQ7Gi8VAVeSby23+aokJrQ3qLpdvu1Q2R4StOvlMd3c8LNJ/lczp7xD A==; X-IronPort-AV: E=McAfee;i="6200,9189,10302"; a="240448204" X-IronPort-AV: E=Sophos;i="5.90,225,1643702400"; d="scan'208";a="240448204" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Mar 2022 07:51:06 -0700 X-IronPort-AV: E=Sophos;i="5.90,225,1643702400"; d="scan'208";a="547364693" Received: from xiaoyaol-hp-g830.ccr.corp.intel.com (HELO [10.249.193.1]) ([10.249.193.1]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Mar 2022 07:51:02 -0700 Message-ID: <714b7d35-911c-ba68-22a9-86b9edb6fe47@intel.com> Date: Thu, 31 Mar 2022 22:50:59 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Firefox/91.0 Thunderbird/91.6.1 Subject: Re: [RFC PATCH v3 17/36] pflash_cfi01/tdx: Introduce ram_mode of pflash for TDVF Content-Language: en-US To: =?UTF-8?Q?Daniel_P=2e_Berrang=c3=a9?= References: <20220317135913.2166202-1-xiaoyao.li@intel.com> <20220317135913.2166202-18-xiaoyao.li@intel.com> <7a8233e4-0cae-b05a-7931-695a7ee87fc9@intel.com> <1d5b0192-75ef-49ad-dc47-cfc0c3c63455@intel.com> From: Xiaoyao Li In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=192.55.52.151; envelope-from=xiaoyao.li@intel.com; helo=mga17.intel.com X-Spam_score_int: -24 X-Spam_score: -2.5 X-Spam_bar: -- X-Spam_report: (-2.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, HK_RANDOM_ENVFROM=0.998, HK_RANDOM_FROM=0.998, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: isaku.yamahata@intel.com, Marcelo Tosatti , kvm@vger.kernel.org, "Michael S. Tsirkin" , Connor Kuehl , Eric Blake , Cornelia Huck , Richard Henderson , =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , qemu-devel@nongnu.org, =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , Gerd Hoffmann , seanjc@google.com, erdemaktas@google.com, Paolo Bonzini , Laszlo Ersek Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 3/31/2022 5:00 PM, Daniel P. Berrangé wrote: > On Thu, Mar 31, 2022 at 04:51:27PM +0800, Xiaoyao Li wrote: >> On 3/22/2022 5:27 PM, Daniel P. Berrangé wrote: >> ... >>> IMHO the AmdSev build for OVMF gets this right by entirely disabling >>> the split OVMF_CODE.fd vs OVMF_VARS.fd, and just having a single >>> OVMF.fd file that is exposed read-only to the guest. >>> >>> This is further represented in $QEMU.git/docs/interop/firmware.json >>> by marking the firmware as 'stateless', which apps like libvirt will >>> use to figure out what QEMU command line to pick. >> >> Hi Daniel, >> >> I don't play with AMD SEV and I'm not sure if AMD SEV requires only single >> OVMF.fd. But IIUC, from edk2 >> >> commit 437eb3f7a8db ("OvmfPkg/QemuFlashFvbServicesRuntimeDxe: Bypass flash >> detection with SEV-ES") >> >> , AMD SEV(-ES) does support NVRAM via proactive VMGEXIT MMIO >> QemuFlashWrite(). If so, AMD SEV seems to be able to support split OVMF, >> right? > > Note that while the traditional OvmfPkg build can be used with > SEV/SEV-ES, this is not viable for measured boot, as it uses > the NVRAM whose content is not measured. > > I was specifically referring to the OvmfPkg/AmdSev build which > doesn't use seprate NVRAM, and has no variables persistence. Thanks for the info. It seems I need to learn more about those. It would be very appreciated if you can provide me some links. > With regards, > Daniel