Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754181AbaDNI6A (ORCPT ); Mon, 14 Apr 2014 04:58:00 -0400 Received: from mga02.intel.com ([134.134.136.20]:63287 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753950AbaDNI56 (ORCPT ); Mon, 14 Apr 2014 04:57:58 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,856,1389772800"; d="scan'208";a="512541464" Message-ID: <534BA30B.5040102@linux.intel.com> Date: Mon, 14 Apr 2014 16:57:47 +0800 From: Jiang Liu Organization: Intel User-Agent: Mozilla/5.0 (Windows NT 6.2; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: Davidlohr Bueso , "Woodhouse, David" CC: "joro@8bytes.org" , "linux-kernel@vger.kernel.org" , "bhe@redhat.com" , "linux-scsi@vger.kernel.org" , "iommu@lists.linux-foundation.org" , "James.Bottomley@hansenpartnership.com" , "bhelgaas@google.com" , "linux-pci@vger.kernel.org" , "scameron@beardog.cce.hp.com" Subject: Re: hpsa driver bug crack kernel down! References: <20140409023935.GE11839@dhcp-16-105.nay.redhat.com> <1397083799.2608.20.camel@buesod1.americas.hpqcorp.net> <1397084904.9519.62.camel@dabdike> <1397085044.9519.63.camel@dabdike> <1397086817.2608.25.camel@buesod1.americas.hpqcorp.net> <1397087425.9519.67.camel@dabdike> <1397089180.2608.27.camel@buesod1.americas.hpqcorp.net> <1397111557.2608.29.camel@buesod1.americas.hpqcorp.net> <20140410071535.GX13491@8bytes.org> <1397119587.19944.14.camel@shinybook.infradead.org> <1397146781.2608.46.camel@buesod1.americas.hpqcorp.net> In-Reply-To: <1397146781.2608.46.camel@buesod1.americas.hpqcorp.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi all, I guess I found the root cause. It's a bug in matching device scope, variable 'level' should be decreased when walking up PCI topology. Could you please help to test following patch? Thanks! Gerry diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c index f445c10..1f8308c 100644 --- a/drivers/iommu/dmar.c +++ b/drivers/iommu/dmar.c @@ -152,7 +152,7 @@ dmar_alloc_pci_notify_info(struct pci_dev *dev, unsigned long event) info->seg = pci_domain_nr(dev->bus); info->level = level; if (event == BUS_NOTIFY_ADD_DEVICE) { - for (tmp = dev, level--; tmp; tmp = tmp->bus->self) { + for (tmp = dev, level--; tmp; level--, tmp = tmp->bus->self) { info->path[level].device = PCI_SLOT(tmp->devfn); info->path[level].function = PCI_FUNC(tmp->devfn); if (pci_is_root_bus(tmp->bus)) On 2014/4/11 0:19, Davidlohr Bueso wrote: > On Thu, 2014-04-10 at 08:46 +0000, Woodhouse, David wrote: >> On Thu, 2014-04-10 at 09:15 +0200, Joerg Roedel wrote: >>> [+ David, VT-d maintainer ] >>> >>> Jiang, David, can you please have a look into this issue? >>> >> >>>>>>>>>>> DMAR:[fault reason 02] Present bit in context entry is clear >>>>>>>>>>> dmar: DRHD: handling fault status reg 602 >>>>>>>>>>> dmar: DMAR:[DMA Read] Request device [02:00.0] fault addr 7f61e000 >> >> That "Present bit in context entry is clear" fault means that we have >> not set up *any* mappings for this PCI device… on this IOMMU. >> >>>> Yes, specifically (finally done bisecting): >>>> >>>> commit 2e45528930388658603ea24d49cf52867b928d3e >>>> Author: Jiang Liu >>>> Date: Wed Feb 19 14:07:36 2014 +0800 >>>> >>>> iommu/vt-d: Unify the way to process DMAR device scope array >> >> This commit is about how we decide which IOMMU a given PCI device is >> attached to. >> >> Thus, my first guess would be that we are quite happily setting up the >> requested DMA maps on the *wrong* IOMMU, and then taking faults when the >> device actually tries to do DMA. >> >> However, I'm not 100% convinced of that. The fault address looks >> suspiciously like a true physical address, not a virtual bus address of >> the type that we'd normally allocate for a dma_map_* operation. Those >> would start at 0xfffff000 and work downwards, typically. >> >> Do you have 'iommu=pt' on the kernel command line? > > No. > >> Can I see the full >> dmesg as this system boots, and also a copy of the DMAR table? > > Attaching a dmesg from one of the kernels that boots. It doesn't appear > to have much of the related information... is there any debug config > option I can enable that might give you more data? > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/