Bug 436899

Summary:	[DMAR] kernel panic with Intel(R) Core(TM)2 Duo CPU E6750
Product:	[Fedora] Fedora	Reporter:	Ian Mortimer <i.mortimer>
Component:	kernel	Assignee:	Kernel Maintainer List <kernel-maint>
Status:	CLOSED DUPLICATE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	low	Docs Contact:
Priority:	low
Version:	8	CC:	hantsy, henry.wayne, muli
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2008-06-12 01:25:48 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Ian Mortimer 2008-03-11 00:17:03 UTC

Description of problem:
The latest Fedora kernel 2.6.24.3-12.fc8 fails to boot with:

Kernel panic - not syncing: DMAR hardware is malfunctioning

This is on a HP Compaq desktop with CPU:

Intel(R) Core(TM)2 Duo CPU     E6750  @ 2.66GHz


Version-Release number of selected component (if applicable):
kernel-2.6.24.3-12.fc8


How reproducible:
Every time.


Steps to Reproduce:
1. Install latest Fedora 8 Kernel
2. Reboot
3.
  
Actual results:
Kernel panic at start of boot.


Expected results:
Boot to proceed as normal.


Additional info:
Boots with kernel 2.6.23.9-85.fc8 and earlier.

Comment 1 Jeroen Beerstra 2008-03-12 09:00:51 UTC

Same problem here, also with a E6750 @ 2.66Ghz (HP Workstation xw4600). Fedora 8
x86_64.

Comment 2 Chuck Ebbert 2008-03-12 23:05:33 UTC

Does booting with the kernel option "intel_iommu=off" help?

Comment 3 Jeroen Beerstra 2008-03-13 10:53:35 UTC

Yes, the system boots with this setting, thank you!

Comment 4 Chuck Ebbert 2008-03-14 20:40:55 UTC

The reporter of bug 436816 says a BIOS update fixed his problem.

Comment 5 Jeroen Beerstra 2008-03-18 07:59:27 UTC

Upgraded to bios v1.06, but no luck.

Comment 6 Ian Mortimer 2008-03-18 22:06:12 UTC

On a HP Compaq dc7800:

panics with latest kernel 2.6.24.3-34.fc8
boots with intel_iommu=off
bios is latest.

Comment 7 henry.wayne 2008-04-02 20:53:08 UTC

Also occurs on HP dc7800 with Intel Quad Core Q6600 on any kernel beyond
2.6.23.15-137.x86_64.fc8

Need IOMMU for v.large memory operations within large simulations.

No BIOS upgrade available from HP.  Where next??

Comment 8 Chuck Ebbert 2008-04-02 22:35:50 UTC

(In reply to comment #7)
> Also occurs on HP dc7800 with Intel Quad Core Q6600 on any kernel beyond
> 2.6.23.15-137.x86_64.fc8
> 
> Need IOMMU for v.large memory operations within large simulations.
> 
> No BIOS upgrade available from HP.  Where next??
> 

iommu=soft
?

Comment 9 henry.wayne 2008-04-04 09:26:41 UTC

iommu=soft works.  no significant degradation in memory ops to 8Gb.  anticipate
no issue scaling upwards from there.

thanks for the setting.  presume i can read up on all configs for iommu somewhere?

Comment 10 Dave Jones 2008-04-04 17:18:21 UTC

ideally, this box would boot without needing to specify options at all.
I'll send mail to some Intel folks and ask them to take a look at this.

Comment 11 Chuck Ebbert 2008-05-15 02:17:45 UTC

(In reply to comment #9)
> iommu=soft works.  no significant degradation in memory ops to 8Gb.  anticipate
> no issue scaling upwards from there.
> 
> thanks for the setting.  presume i can read up on all configs for iommu somewhere?

In the kernel-doc package, files kernel-parameters.txt and x86_64/boot-options.txt

(I still don't understand why it panics the box if the hardware isn't working.
It should just fail the driver init and continue...)

Comment 12 Chuck Ebbert 2008-06-12 01:25:48 UTC


*** This bug has been marked as a duplicate of 445553 ***

Comment 13 Hantsy Bai 2009-12-31 10:53:32 UTC

I encounter the same problem on my new netebook- hp compaq cq40 609tx...
I used the intel_iommu=off to start up installer...
It avoid the kernelpanic error, but stop on hardware detection at starting up installer...