Bug 681917

Summary: KVM Host panics after starting multiple VMs
Product: Red Hat Enterprise Linux 6 Reporter: Jason <bugzilla>
Component: kernelAssignee: Red Hat Kernel Manager <kernel-mgr>
Status: CLOSED DUPLICATE QA Contact: Red Hat Kernel QE team <kernel-qe>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 6.0CC: riel
Target Milestone: rc   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2011-11-04 14:53:32 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:

Description Jason 2011-03-03 15:27:55 UTC 
Description of problem:
When starting several KVM vms at a time (either through autoload, or virsh start <guestname> on the command line), the kernel would panic with various reasons:

<157>Feb 28 18:51:37 dlmtesta01 BUG: unable to handle kernel NULL pointer dereference at 0000000000000049
<157>Mar  2 14:46:31 dlmtesta01 BUG: unable to handle kernel paging request at 0000000000a00ff9
<157>Mar  2 15:11:00 dlmtesta01 BUG: unable to handle kernel paging
<157>Mar  3 09:51:08 dlmtesta01 BUG: Bad page map in process sleep  pte:3e86400054520000 pmd:8b71fc067
<157>Mar  3 09:51:36 dlmtesta01 BUG: Bad page map in process qemu-kvm  pte:bfb9e0054520000 pmd:8b26d6067
<157>Mar  3 09:51:37 dlmtesta01 BUG: Bad page map in process qemu-kvm  pte:bfb9e0054520000 pmd:11a831a067
<157>Mar  3 09:51:37 dlmtesta01 BUG: Bad page map in process qemu-kvm  pte:6031730054520000 pmd:1190793067
<157>Mar  3 09:51:37 dlmtesta01 BUG: Bad page map in process qemu-kvm  pte:2a56990054520000 pmd:11907a9067
<157>Mar  3 09:51:40 dlmtesta01 BUG: Bad page map in process qemu-kvm  pte:c2aaa20054520000 pmd:8b46bf067
<157>Mar  3 09:52:08 dlmtesta01 BUG: Bad page map in process sleep  pte:6031730054520000 pmd:8b71fc067

I have not experienced a kernel panic since I blacklisted the ipv6 kernel module as suggested in BUGZILLA:533087 (see link below)

Version-Release number of selected component (if applicable):
kernel-2.6.32-71.18.1.el6.x86_64
qemu-kvm-0.12.1.2-2.113.el6_0.6.x86_64

How reproducible:
I was able to reproduce the panic every time I rebooted

Steps to Reproduce:
1. Add ~5-6 kvm vms to autoload
2. Reboot

or

1. for i in `seq 1 5`; do
virsh start guest$i
done
  
Actual results:
Kernel panic on the host.

Expected results:
No panic

Additional info:
Seems identical to this bug:
https://bugzilla.redhat.com/show_bug.cgi?id=533087
Comment 2 RHEL Program Management 2011-04-04 02:48:18 UTC 
Since RHEL 6.1 External Beta has begun, and this bug remains
unresolved, it has been rejected as it is not proposed as
exception or blocker.

Red Hat invites you to ask your support representative to
propose this request, if appropriate and relevant, in the
next release of Red Hat Enterprise Linux.
Comment 3 RHEL Program Management 2011-10-07 15:24:31 UTC 
Since RHEL 6.2 External Beta has begun, and this bug remains
unresolved, it has been rejected as it is not proposed as
exception or blocker.

Red Hat invites you to ask your support representative to
propose this request, if appropriate and relevant, in the
next release of Red Hat Enterprise Linux.
Comment 4 Rik van Riel 2011-11-04 14:53:32 UTC 

*** This bug has been marked as a duplicate of bug 533087 ***