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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 7A679C433F5 for ; Mon, 10 Sep 2018 13:26:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CAF64206BB for ; Mon, 10 Sep 2018 13:26:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CAF64206BB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728593AbeIJSUi (ORCPT ); Mon, 10 Sep 2018 14:20:38 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:57490 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727970AbeIJSUh (ORCPT ); Mon, 10 Sep 2018 14:20:37 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 88D5C80D; Mon, 10 Sep 2018 06:26:32 -0700 (PDT) Received: from [10.4.12.131] (e110467-lin.emea.arm.com [10.4.12.131]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BEB683F557; Mon, 10 Sep 2018 06:26:31 -0700 (PDT) Subject: Re: 4.19-rc3: IOMMU PT warnings: WARNING: CPU: 0 PID: 1 at mm/page_alloc.c:4065 __alloc_pages_slowpath+0xb7b/0xcd0 To: Christoph Hellwig , Meelis Roos Cc: iommu@lists.linux-foundation.org, Linux Kernel list References: <20180910132304.GA20244@lst.de> From: Robin Murphy Message-ID: Date: Mon, 10 Sep 2018 14:26:30 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20180910132304.GA20244@lst.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/09/18 14:23, Christoph Hellwig wrote: > On Mon, Sep 10, 2018 at 11:16:12AM +0300, Meelis Roos wrote: >> In 4.19-rc1, I found that to keep Intel integrated graphics working when >> VT-d is on, I need to have IOMMU passthough on or GPU init would fail >> with DMAR error and the screen would display static gibberish. So I >> turned IOMMU PT on by default in kernel config. It worked, also in rc2. >> >> Now with rc3, it still works but I get some warning splats in dmesg >> about IOMMU passthrough: > > Any chance you could bisect this down to a specific commit? For > a start it might be worth if it is reproducable with: > > git://git.infradead.org/users/hch/dma-mapping.git dma-mapping-4.19-2 > > which were the only dma-mapping changes post -rc2. Given the __alloc_pages_slowpath() warning, this looks like it's probably stemming from the oversized PASID table issue which a few other folks have hit too. I think this patch is the most up-to-date fix: https://www.mail-archive.com/iommu@lists.linux-foundation.org/msg25639.html Robin.