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 58061C433F5 for ; Wed, 27 Apr 2022 00:01:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356289AbiD0AEl (ORCPT ); Tue, 26 Apr 2022 20:04:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36012 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231330AbiD0AEj (ORCPT ); Tue, 26 Apr 2022 20:04:39 -0400 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9FCFE177731; Tue, 26 Apr 2022 17:01:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1651017690; x=1682553690; h=message-id:subject:from:to:cc:date:in-reply-to: references:mime-version:content-transfer-encoding; bh=yJVAQLGQpmSEwTIQy0c+wdcVPv3sKrYh2NRxvL5xBC0=; b=lph9hf2Nld+3oexIUm65IbGXk8OTlYnnQ8k05vx6lB5wQEEZvtaYdCIZ YbVYTJ6Cp/Kx2MhWbyT25BNZYE7XRpVQVVHuhzUbuXsn4QfM8QDFScnXb ocpyz5OLP6O7sH9RUZBtji255taXEz6UCt2VyAHQzm4f+Z/EKCQE3li5C hwgVnlzUi4o15LqQ75ys9RJXTYMFpBXShCX7ZS3Xb10rq04kZxcQpK6fF 4vh/ae8aSFmPS9IUbqear23i/+UJC/bzJ+Ww1g8ga3vvJ795S4sGvCLNx wwQQe8wydB796eZ8LAEDa7WrREbwi832bZO1ROpKNStmYmhIgTdUQBqDA w==; X-IronPort-AV: E=McAfee;i="6400,9594,10329"; a="265283244" X-IronPort-AV: E=Sophos;i="5.90,292,1643702400"; d="scan'208";a="265283244" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Apr 2022 17:01:30 -0700 X-IronPort-AV: E=Sophos;i="5.90,292,1643702400"; d="scan'208";a="564824694" Received: from ssaride-mobl.amr.corp.intel.com (HELO khuang2-desk.gar.corp.intel.com) ([10.254.0.221]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Apr 2022 17:01:27 -0700 Message-ID: <98af78402861b1982607c5fd14b0c89403c042a6.camel@intel.com> Subject: Re: [PATCH v3 05/21] x86/virt/tdx: Detect P-SEAMLDR and TDX module From: Kai Huang To: Dave Hansen , linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: seanjc@google.com, pbonzini@redhat.com, len.brown@intel.com, tony.luck@intel.com, rafael.j.wysocki@intel.com, reinette.chatre@intel.com, dan.j.williams@intel.com, peterz@infradead.org, ak@linux.intel.com, kirill.shutemov@linux.intel.com, sathyanarayanan.kuppuswamy@linux.intel.com, isaku.yamahata@intel.com Date: Wed, 27 Apr 2022 12:01:25 +1200 In-Reply-To: <104a6959-3bd4-1e75-5e3d-5dc3ef025ed0@intel.com> References: <104a6959-3bd4-1e75-5e3d-5dc3ef025ed0@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, 2022-04-26 at 13:56 -0700, Dave Hansen wrote: > On 4/5/22 21:49, Kai Huang wrote: > > The P-SEAMLDR (persistent SEAM loader) is the first software module that > > runs in SEAM VMX root, responsible for loading and updating the TDX > > module. Both the P-SEAMLDR and the TDX module are expected to be loaded > > before host kernel boots. > > Why bother with the P-SEAMLDR here at all? The kernel isn't loading the > TDX module in this series. Why not just call into the TDX module directly? It's not absolutely needed in this series. I choose to detect P-SEAMLDR because detecting it can also detect the TDX module, and eventually we will need to support P-SEAMLDR because the TDX module runtime update uses P-SEAMLDR's SEAMCALL to do that. Also, even for this series, detecting the P-SEAMLDR allows us to provide the P- SEAMLDR information to user at a basic level in dmesg: [..] tdx: P-SEAMLDR: version 0x0, vendor_id: 0x8086, build_date: 20211209, build_num 160, major 1, minor 0 This may be useful to users, but it's not a hard requirement for this series. -- Thanks, -Kai