linux-kernel - Re: IOMMU+DMAR causing NMIs-s

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Date:	Wed, 13 Jul 2016 11:13:59 -0400
From:	Linda Knippers <linda.knippers@....com>
To:	Alex Williamson <alex.williamson@...hat.com>,
	Joerg Roedel <joro@...tes.org>
CC:	Meelis Roos <mroos@...ux.ee>,
	David Woodhouse <dwmw2@...radead.org>,
	<iommu@...ts.linux-foundation.org>,
	Linux Kernel list <linux-kernel@...r.kernel.org>
Subject: Re: IOMMU+DMAR causing NMIs-s

On 7/13/2016 10:48 AM, Alex Williamson wrote:
> On Wed, 13 Jul 2016 12:18:59 +0200
> Joerg Roedel <joro@...tes.org> wrote:
> 
>> On Wed, Jul 13, 2016 at 12:58:24PM +0300, Meelis Roos wrote:
>>>>> Just got http://kodu.ut.ee/~mroos/4.6-dmar-fault2.png when playing with 
>>>>> BIOS settings (disabling NUMA). It is the first time I see at least some 
>>>>> info in NMI decode.  
>>>>
>>>> This looks interesting. Can you please post output of 'lspci -vvv' and
>>>> 'lspci -t'?  
>>>
>>> Here.  
>>
>> Thanks. So device 00:1e.0 is a PCI-bridge which has some 32-bit
>> PCI-devices behind it. One of these devices tries to read address
>> 0xb000, which is blocked by the IOMMU and causes the fault seen in the
>> screen-shot. The fault also causes a PCI-error which is then reported
>> through the NMI, causing your kernel panic.
>>
>> So the 32bit PCI devices behind the bridge are:
>>
>> 01:03.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] ES1000 (rev 02) (prog-if 00 [VGA controller])
>> 01:04.0 System peripheral: Compaq Computer Corporation Integrated Lights Out Controller (rev 03)
>> 01:04.2 System peripheral: Compaq Computer Corporation Integrated Lights Out  Processor (rev 03)
>> 01:04.4 USB controller: Hewlett-Packard Company Integrated Lights-Out Standard Virtual USB Controller (prog-if 00 [UHCI])
>> 01:04.6 IPMI SMIC interface: Hewlett-Packard Company Integrated Lights-Out Standard KCS Interface (prog-if 01)
>>
>> Can you try to disable this 'Lights Out' processor? Maybe it is causing
>> the issues. On the other side, the radeon driver for the ATI card is
>> also know for causing faults from time to time. Can you capture the
>> kernel messages right before a crash too?
> 
> IIRC, blacklisting the hpwdt module can defuse those NMIs and might
> help us see more of the actual DMAR faults.  Blacklist in modprobe.d
> and rebuild initrd. Thanks,
> 
> Alex
> 
> PS - never assume BIOS release notes are actually complete

I agree. I'd do the BIOS update and also make sure the iLO FW is current.

-- ljk
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> iommu@...ts.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/iommu
> 

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