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=-8.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 9625AC4338F for ; Mon, 26 Jul 2021 12:25:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7607160E78 for ; Mon, 26 Jul 2021 12:25:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234004AbhGZLpO (ORCPT ); Mon, 26 Jul 2021 07:45:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57042 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233968AbhGZLpN (ORCPT ); Mon, 26 Jul 2021 07:45:13 -0400 Received: from theia.8bytes.org (8bytes.org [IPv6:2a01:238:4383:600:38bc:a715:4b6d:a889]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4A9F3C061757 for ; Mon, 26 Jul 2021 05:25:42 -0700 (PDT) Received: by theia.8bytes.org (Postfix, from userid 1000) id 6D7EE2B0; Mon, 26 Jul 2021 14:25:40 +0200 (CEST) Date: Mon, 26 Jul 2021 14:25:39 +0200 From: Joerg Roedel To: Kyung Min Park Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, baolu.lu@linux.intel.com, dwmw2@infradead.org, will@kernel.org, yian.chen@intel.com, sohil.mehta@intel.com, ravi.v.shankar@intel.com, ashok.raj@intel.com Subject: Re: [PATCH v2] iommu/vt-d: Dump DMAR translation structure Message-ID: References: <20210722042453.10579-1-kyung.min.park@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210722042453.10579-1-kyung.min.park@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 21, 2021 at 09:24:53PM -0700, Kyung Min Park wrote: > When the dmar translation fault happens, the kernel prints a single line > fault reason with corresponding hexadecimal code defined in the Intel VT-d > specification. > > Currently, when user wants to debug the translation fault in detail, > debugfs is used for dumping the dmar_translation_struct, which is not > available when the kernel failed to boot. > > Dump the DMAR translation structure, pagewalk the IO page table and print > the page table entry when the fault happens. > > Signed-off-by: Kyung Min Park This is too much noise in dmesg for a single dmar fault. Please hide that additional debug information behind a debug kernel option for the VT-d driver. Thanks, Joerg