From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <50CF480F.4060804@redhat.com> Date: Mon, 17 Dec 2012 11:27:59 -0500 From: Don Dutile MIME-Version: 1.0 To: Robert Hancock CC: Jason Gao , linux-kernel , linux-pci@vger.kernel.org, kvm Subject: Re: DMAR and DRHD errors[DMAR:[fault reason 06] PTE Read access is not set] Vt-d & intel_iommu References: <50CB9ADC.2020103@redhat.com> <50CCF6DB.7080204@gmail.com> In-Reply-To: <50CCF6DB.7080204@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-kernel-owner@vger.kernel.org List-ID: On 12/15/2012 05:16 PM, Robert Hancock wrote: > On 12/14/2012 03:32 PM, Don Dutile wrote: >> On 12/13/2012 04:50 AM, Jason Gao wrote: >>> Dear List: >>> >>> Description of problem: >>> After installed Centos 6.3(RHEL6.3) on my Dell R710(lastest >>> bios:Version: 6.3.0,Release Date: 07/24/2012) server,and updated >>> lastest kernel "2.6.32-279.14.1.el6.x86_64",I want to use the Intel >>> 82576 ET Dual Port nic's SR-IOV feature,assigning VFs to kvm guest >>> >>> appended kernel boot parameter: intel_iommu=on,after boot with the >>> following messages: >>> >>> Dec 13 16:58:15 2 kernel: DRHD: handling fault status reg 2 >>> Dec 13 16:58:15 2 kernel: DMAR:[DMA Read] Request device [03:00.0] >>> fault addr ffe65000 >>> Dec 13 16:58:15 2 kernel: DMAR:[fault reason 06] PTE Read access is >>> not set >>> Dec 13 16:58:15 2 kernel: DRHD: handling fault status reg 102 >>> Dec 13 16:58:15 2 kernel: DMAR:[DMA Read] Request device [03:00.0] >>> fault addr ffe8a000 >>> Dec 13 16:58:15 2 kernel: DMAR:[fault reason 06] PTE Read access is >>> not set >>> Dec 13 16:58:15 2 kernel: scsi 0:0:32:0: Enclosure DP >>> BACKPLANE 1.07 PQ: 0 ANSI: 5 >>> Dec 13 16:58:15 2 kernel: DRHD: handling fault status reg 202 >>> Dec 13 16:58:15 2 kernel: DMAR:[DMA Read] Request device [03:00.0] >>> fault addr ffe89000 >>> Dec 13 16:58:15 2 kernel: DMAR:[fault reason 06] PTE Read access is >>> not set >>> >>> full dmesg detail: >>> http://pastebin.com/BzFQV0jU >>> lspci -vvv full detail: >>> http://pastebin.com/9rP2d1br >>> >>> >>> it's a production server,and I'm not sure if this is a critical >>> problem,how to fix it,any help would be greatly appreciated. >> >> DMAR table does not have an entry for this device to this region. >> Once the driver reconfigs/resets the device to stop polling bios-boot >> cmd rings and use (new) OS (dma-mapped) rings, there's a period of time >> during this transition that the hw is babbling away to an area that is no >> longer mapped. > > Maybe some kind of boot PCI quirk is needed to stop the device DMA activity before enabling the IOMMU? > No, lack of a *proper* RMRR for this device is the source of the problem; that's why the RMRR's exist -- so this transition state does not cause these types of problems. > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html