Bug 728476

Summary:	machine panics with "DMAR hardware is malfunctioning"
Product:	Red Hat Enterprise Linux 6	Reporter:	Dave Airlie <airlied>
Component:	kernel	Assignee:	Dave Airlie <airlied>
Status:	CLOSED ERRATA	QA Contact:	Desktop QE <desktop-qa-list>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	6.2	CC:	tpelka, vhumpa
Target Milestone:	rc	Keywords:	Regression
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	kernel-2.6.32-212.el6	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2011-12-06 14:00:35 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Bug Depends On:
Bug Blocks:	750914

Description Dave Airlie 2011-08-05 09:53:33 UTC

Description of problem:

On HP ELiteBook 2540p with Intel Ironlake Graphics, the drm rebased uncovered a bug in the IOMMU hardware. This causes the panic unless graphics passthrough is enabled.

Version-Release number of selected component (if applicable):


How reproducible:

Run for a few hours with a kernel build in a terminal

Plan is get Intel to fix or if not just disable IOMMU for graphics device for G4x and Ironlake.

Comment 1 RHEL Program Management 2011-08-05 10:09:43 UTC

This request was evaluated by Red Hat Product Management for inclusion
in a Red Hat Enterprise Linux maintenance release. Product Management has 
requested further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed 
products. This request is not yet committed for inclusion in an Update release.

Comment 3 Dave Airlie 2011-10-11 12:19:08 UTC

Better reproducer,

Get a ILK laptop that supports VT-d properly, HP Elitebook 2540p, not a lot of Lenovo ILK fail to enable graphics VT-d due to a bios bug.

Use desktop effects to enable compiz, open a gnome-terminal

run while [ 1 == 1 ]; do find . ; done

Leave running as long as possible, eventually machine will hang.

Comment 4 Dave Airlie 2011-10-11 14:30:20 UTC

oh you have to enable VT-d in the BIOS and boot EL6.2 kernels with intel_iommu=on

Comment 8 Dave Airlie 2011-10-18 08:24:20 UTC

If the Ironlake can enable VT-D and if VT-d works on it.

Some BIOSes mess up, you'll see
DMAR: BIOS has allocated no shadow GTT; disabling IOMMU for graphics

in dmesg, reproducing on these is also difficult (if possible at all).

Comment 11 Aristeu Rozanski 2011-10-25 14:51:28 UTC

Patch(es) available on kernel-2.6.32-212.el6

Comment 15 errata-xmlrpc 2011-12-06 14:00:35 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHSA-2011-1530.html