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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 88D99C49EAB for ; Mon, 28 Jun 2021 09:31:10 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5913B619C5 for ; Mon, 28 Jun 2021 09:31:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5913B619C5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DFB606E3DF; Mon, 28 Jun 2021 09:31:04 +0000 (UTC) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by gabe.freedesktop.org (Postfix) with ESMTP id E84366EACA; Thu, 24 Jun 2021 11:34:21 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 847F01063; Thu, 24 Jun 2021 04:34:21 -0700 (PDT) Received: from [10.57.9.136] (unknown [10.57.9.136]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 361C23F718; Thu, 24 Jun 2021 04:34:14 -0700 (PDT) To: Will Deacon References: <20210619034043.199220-1-tientzu@chromium.org> <20210619034043.199220-7-tientzu@chromium.org> <76c3343d-72e5-9df3-8924-5474ee698ef4@quicinc.com> <20210623183736.GA472@willie-the-truck> <19d4c7a2-744d-21e0-289c-a576e1f0e6f3@quicinc.com> <20210624054315.GA25381@lst.de> <364e6715-eafd-fc4a-e0af-ce2a042756b4@arm.com> <20210624111855.GA1382@willie-the-truck> From: Robin Murphy Message-ID: <452155d2-c98e-23f6-86d6-3a2ff2e74783@arm.com> Date: Thu, 24 Jun 2021 12:34:09 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: <20210624111855.GA1382@willie-the-truck> Content-Language: en-GB X-Mailman-Approved-At: Mon, 28 Jun 2021 09:31:03 +0000 Subject: Re: [Intel-gfx] [PATCH v14 06/12] swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: heikki.krogerus@linux.intel.com, linux-devicetree , peterz@infradead.org, benh@kernel.crashing.org, dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk, grant.likely@arm.com, paulus@samba.org, Frank Rowand , Christoph Hellwig , Jianxiong Gao , Stefano Stabellini , Saravana Kannan , mpe@ellerman.id.au, Joerg Roedel , "Rafael J . Wysocki" , mingo@kernel.org, Bartosz Golaszewski , bskeggs@redhat.com, linux-pci@vger.kernel.org, xen-devel@lists.xenproject.org, Marek Szyprowski , Dan Williams , matthew.auld@intel.com, Nicolas Boichat , thomas.hellstrom@linux.intel.com, Jim Quinlan , Konrad Rzeszutek Wilk , intel-gfx@lists.freedesktop.org, Rob Herring , Bjorn Helgaas , Claire Chang , boris.ostrovsky@oracle.com, Andy Shevchenko , jgross@suse.com, airlied@linux.ie, Thierry Reding , Greg KH , Randy Dunlap , Qian Cai , lkml , "list@263.net:IOMMU DRIVERS" , xypron.glpk@gmx.de, Tom Lendacky , linuxppc-dev@lists.ozlabs.org, bauerman@linux.ibm.com Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On 2021-06-24 12:18, Will Deacon wrote: > On Thu, Jun 24, 2021 at 12:14:39PM +0100, Robin Murphy wrote: >> On 2021-06-24 07:05, Claire Chang wrote: >>> On Thu, Jun 24, 2021 at 1:43 PM Christoph Hellwig wrote: >>>> >>>> On Wed, Jun 23, 2021 at 02:44:34PM -0400, Qian Cai wrote: >>>>> is_swiotlb_force_bounce at /usr/src/linux-next/./include/linux/swiotlb.h:119 >>>>> >>>>> is_swiotlb_force_bounce() was the new function introduced in this patch here. >>>>> >>>>> +static inline bool is_swiotlb_force_bounce(struct device *dev) >>>>> +{ >>>>> + return dev->dma_io_tlb_mem->force_bounce; >>>>> +} >>>> >>>> To me the crash looks like dev->dma_io_tlb_mem is NULL. Can you >>>> turn this into : >>>> >>>> return dev->dma_io_tlb_mem && dev->dma_io_tlb_mem->force_bounce; >>>> >>>> for a quick debug check? >>> >>> I just realized that dma_io_tlb_mem might be NULL like Christoph >>> pointed out since swiotlb might not get initialized. >>> However, `Unable to handle kernel paging request at virtual address >>> dfff80000000000e` looks more like the address is garbage rather than >>> NULL? >>> I wonder if that's because dev->dma_io_tlb_mem is not assigned >>> properly (which means device_initialize is not called?). >> >> What also looks odd is that the base "address" 0xdfff800000000000 is held in >> a couple of registers, but the offset 0xe looks too small to match up to any >> relevant structure member in that dereference chain :/ > > FWIW, I've managed to trigger a NULL dereference locally when swiotlb hasn't > been initialised but we dereference 'dev->dma_io_tlb_mem', so I think > Christoph's suggestion is needed regardless. Ack to that - for SWIOTLB_NO_FORCE, io_tlb_default_mem will remain NULL. The massive jump in KernelCI baseline failures as of yesterday looks like every arm64 machine with less than 4GB of RAM blowing up... Robin. > But I agree that it won't help > with the issue reported by Qian Cai. > > Qian Cai: please can you share your .config and your command line? > > Thanks, > > Will > _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx