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=-7.5 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 E6AA8C433DF for ; Mon, 24 Aug 2020 06:31:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C314920720 for ; Mon, 24 Aug 2020 06:31:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726189AbgHXGbc (ORCPT ); Mon, 24 Aug 2020 02:31:32 -0400 Received: from mga07.intel.com ([134.134.136.100]:9119 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725730AbgHXGba (ORCPT ); Mon, 24 Aug 2020 02:31:30 -0400 IronPort-SDR: fciyrLnLhcyDOMgKygdEtc4ZIMvLA2YrCx7dv/dyfyFqUH6/0KfR4KK7/DDub24o10JQogztvf +DDARQXrKuIg== X-IronPort-AV: E=McAfee;i="6000,8403,9722"; a="220116974" X-IronPort-AV: E=Sophos;i="5.76,347,1592895600"; d="scan'208";a="220116974" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Aug 2020 23:31:29 -0700 IronPort-SDR: 0V4ihqf+WXUXYsQ0IJPdnuxlWzcWibJUmcIDItXdB12I1iL9p5Tn/KGpZmxlqjCoYrCqAw7vJq BDM21KyjS4Ow== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.76,347,1592895600"; d="scan'208";a="328377856" Received: from blu2-mobl3.ccr.corp.intel.com (HELO [10.254.214.99]) ([10.254.214.99]) by orsmga008.jf.intel.com with ESMTP; 23 Aug 2020 23:31:24 -0700 Cc: baolu.lu@linux.intel.com, ashok.raj@intel.com, jacob.jun.pan@intel.com, kevin.tian@intel.com, jamessewart@arista.com, tmurphy@arista.com, dima@arista.com, sai.praneeth.prakhya@intel.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 07/15] iommu/vt-d: Delegate the dma domain to upper layer To: Chris Wilson , David Woodhouse , Joerg Roedel References: <20190525054136.27810-1-baolu.lu@linux.intel.com> <20190525054136.27810-8-baolu.lu@linux.intel.com> <159803479017.29194.1359332295829225843@build.alporthouse.com> From: Lu Baolu Message-ID: <65125687-14ae-182f-da07-7d29b4910364@linux.intel.com> Date: Mon, 24 Aug 2020 14:31:23 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <159803479017.29194.1359332295829225843@build.alporthouse.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Chris, On 2020/8/22 2:33, Chris Wilson wrote: > Quoting Lu Baolu (2019-05-25 06:41:28) >> This allows the iommu generic layer to allocate a dma domain and >> attach it to a device through the iommu api's. With all types of >> domains being delegated to upper layer, we can remove an internal >> flag which was used to distinguish domains mananged internally or >> externally. > > I'm seeing some really strange behaviour with this patch on a 32b > Skylake system (and still present on mainline). Before this patch > everything is peaceful and appears to work correctly. Applying this patch, > and we fail to initialise the GPU with a few DMAR errors reported, e.g. > > [ 20.279445] DMAR: DRHD: handling fault status reg 3 > [ 20.279508] DMAR: [DMA Read] Request device [00:02.0] fault addr 8900a000 [fault reason 05] PTE Write access is not set > > Setting an identity map for the igfx made the DMAR errors disappear, but > the GPU still failed to initialise. > > There's no difference in the DMAR configuration dmesg between working and > the upset patch. And the really strange part is that switching to a 64b > kernel with this patch, it's working. > > Any suggestions on what I should look for? Can the patch titled "[PATCH] iommu/intel: Handle 36b addressing for x86-32" solve this problem? Best regards, baolu