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 A14E7C433EF for ; Wed, 27 Apr 2022 21:30:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237600AbiD0VeC (ORCPT ); Wed, 27 Apr 2022 17:34:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34068 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237509AbiD0Vd4 (ORCPT ); Wed, 27 Apr 2022 17:33:56 -0400 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A372827152; Wed, 27 Apr 2022 14:30:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1651095044; x=1682631044; h=message-id:subject:from:to:cc:date:in-reply-to: references:mime-version:content-transfer-encoding; bh=9AnR0+i4WyZuMptJB4sGh0+ILBAmTrqUC5l0VYBK5DQ=; b=OLVFTDseiEs8H9fUvj40yBhty5zkBeBjcMUOSNhl1W0gPhmb9MTZbD1f OMdcrmwDD5XnR7YgrJ0AqK0c9SmSY5cIg/0Q+tTaWOdloNoXekPimZZi/ 3by0OvjfJdfZUhrA1KfOb+7/v0YKYihas94uEd/erZiWGqepC+59pR4tt gWCLDpFYRp6cMI0ngTm0rzmQdnl2LB1BiC6nOhbULKyC3sZyigiy3H+vC Iy4flTapKyFfpn38d0kjYdxTzbrbpYxg+6dGB7BLbcOlByPxdeBjBC6V7 wRWNo6/VQT8qX7+sD45PN86w1aIJyKdT7Ulb5fp/d+5ZEv/d29nTzbif9 w==; X-IronPort-AV: E=McAfee;i="6400,9594,10330"; a="246634544" X-IronPort-AV: E=Sophos;i="5.90,294,1643702400"; d="scan'208";a="246634544" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Apr 2022 14:30:44 -0700 X-IronPort-AV: E=Sophos;i="5.90,294,1643702400"; d="scan'208";a="705733567" Received: from rrnambia-mobl.amr.corp.intel.com (HELO khuang2-desk.gar.corp.intel.com) ([10.254.60.78]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Apr 2022 14:30:41 -0700 Message-ID: <68484e168226037c3a25b6fb983b052b26ab3ec1.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: Thu, 28 Apr 2022 09:30:39 +1200 In-Reply-To: <49cc6848-47ae-9c25-f479-c5aed8c892df@intel.com> References: <104a6959-3bd4-1e75-5e3d-5dc3ef025ed0@intel.com> <98af78402861b1982607c5fd14b0c89403c042a6.camel@intel.com> <49cc6848-47ae-9c25-f479-c5aed8c892df@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 Wed, 2022-04-27 at 07:24 -0700, Dave Hansen wrote: > On 4/26/22 17:01, Kai Huang wrote: > > 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. > > We've had a lot of problems in general with this code trying to do too > much at once. I thought we agreed that this was going to only contain > the minimum code to make TDX functional. It seems to be creeping to > grow bigger and bigger. > > Am I remembering this wrong? OK. I'll remove the P-SEAMLDR related code. -- Thanks, -Kai