Bug 834583
Summary: | kernel-rt-3.2.20-rt32.44.el6rt.x86_64 floods the console with "DMAR [fault reason 02] Present bit in context entry is clear" | ||
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Product: | Red Hat Enterprise MRG | Reporter: | David Sommerseth <davids> |
Component: | realtime-kernel | Assignee: | John Kacur <jkacur> |
Status: | CLOSED ERRATA | QA Contact: | David Sommerseth <davids> |
Severity: | high | Docs Contact: | |
Priority: | high | ||
Version: | 2.2 | CC: | bhu, iboverma, jkastner, lgoncalv, ovasik, williams |
Target Milestone: | 2.2 | ||
Target Release: | --- | ||
Hardware: | Unspecified | ||
OS: | Unspecified | ||
Whiteboard: | |||
Fixed In Version: | Doc Type: | Bug Fix | |
Doc Text: |
* Cause: intel-iommu.ko driver has interrupt handling problems with some Sandy Bridge hardware
* Consequence: Console gets flooded at boot with DMAR interrupt messages
* Fix: default intel-iommu to off and allow loading with kernel command line 'intel_iommu=on'
* Result: No DMAR interrupt message flood
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Story Points: | --- |
Clone Of: | Environment: | ||
Last Closed: | 2012-09-19 18:04:09 UTC | Type: | Bug |
Regression: | --- | Mount Type: | --- |
Documentation: | --- | CRM: | |
Verified Versions: | Category: | --- | |
oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
Cloudforms Team: | --- | Target Upstream Version: | |
Embargoed: |
Description
David Sommerseth
2012-06-22 13:57:51 UTC
A common issue a couple of boxes is this warning: ------------------------------------------------------------------ DMAR: DRHD base: 0x000000fed90000 flags: 0x1 IOMMU fed90000: ver 1:0 cap c9008020660262 ecap f010da DMAR: RMRR base: 0x000000f1ffd000 end: 0x000000f1ffffff DMAR: No ATSR found IOAPIC id 8 under DRHD base 0xfed90000 Your BIOS has requested that x2apic be disabled. This will leave your machine vulnerable to irq-injection attacks. Use 'intremap=no_x2apic_optout' to override BIOS request. Enabled IRQ remapping in x2apic mode Enabling x2apic Enabled x2apic ------------------------------------------------------------------ Notes from David: > btw ... the DMAR issue ... that's present on upstream 3.2.20 kernel as well ... that's the source from kernel.org without PREEMPT_RT patch but with our config > and intel_iommu=off "removes" this issue ... so we have something to poke further on Looking at beaker test run on system intel-s3ea2-04.rhts.eng.bos.redhat.com, looks like this might be a system affected by the DMAR issue. Console log: http://beaker-archive.app.eng.bos.redhat.com/beaker-logs/2012/06/2555/255532/544410/console.log Technical note added. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. New Contents: * Cause: intel-iommu.ko driver has interrupt handling problems with some Sandy Bridge hardware * Consequence: Console gets flooded at boot with DMAR interrupt messages * Fix: default intel-iommu to off and allow loading with kernel command line 'intel_iommu=on' * Result: No DMAR interrupt message flood from the changelog of 3.2.22-rt34.46, - [mrg] turned off INTEL_IOMMU_DEFAULT_ON (DMAR flood issue) [BZ# 834583] 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-2012-1282.html |