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 X-Spam-Level: X-Spam-Status: No, score=-6.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D6AC8C4338F for ; Fri, 20 Aug 2021 19:01:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B80696112E for ; Fri, 20 Aug 2021 19:01:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236590AbhHTTBr (ORCPT ); Fri, 20 Aug 2021 15:01:47 -0400 Received: from mga17.intel.com ([192.55.52.151]:4596 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229512AbhHTTBq (ORCPT ); Fri, 20 Aug 2021 15:01:46 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10082"; a="197082645" X-IronPort-AV: E=Sophos;i="5.84,338,1620716400"; d="scan'208";a="197082645" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Aug 2021 12:01:08 -0700 X-IronPort-AV: E=Sophos;i="5.84,338,1620716400"; d="scan'208";a="506580400" Received: from jmorauga-mobl.amr.corp.intel.com (HELO skuppusw-mobl5.amr.corp.intel.com) ([10.209.135.55]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Aug 2021 12:01:06 -0700 Subject: Re: [PATCH v5 06/12] x86/tdx: Get TD execution environment information via TDINFO To: Andi Kleen , Borislav Petkov Cc: Thomas Gleixner , Ingo Molnar , Peter Zijlstra , Andy Lutomirski , Peter H Anvin , Dave Hansen , Tony Luck , Dan Williams , Kirill Shutemov , Sean Christopherson , Kuppuswamy Sathyanarayanan , x86@kernel.org, linux-kernel@vger.kernel.org References: <20210804181329.2899708-1-sathyanarayanan.kuppuswamy@linux.intel.com> <20210804181329.2899708-7-sathyanarayanan.kuppuswamy@linux.intel.com> <174d5062-3618-4343-bdfb-22b5cd2662f8@linux.intel.com> <5c4b8cff-ebc0-515f-acb3-aee53f955e4c@linux.intel.com> From: "Kuppuswamy, Sathyanarayanan" Message-ID: <428c09d3-f636-2a99-e394-e46b57c38b29@linux.intel.com> Date: Fri, 20 Aug 2021 12:01:04 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <5c4b8cff-ebc0-515f-acb3-aee53f955e4c@linux.intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/20/21 11:58 AM, Andi Kleen wrote: > > > Without working TDCALLs the error message won't appear anywhere. The only practical way to debug > such a problem is a kernel debugger. > > Also printing an error message might end up recursing because the console write would trigger TDCALL > again, or eventually stop because the console lock is already taken. In any case it won't work. Yes, good point. In this case, adding debug print will not work. But I can add more comments to the code. -- Sathyanarayanan Kuppuswamy Linux Kernel Developer