Bug 588878 - Rebooting a kernel with kvmclock enabled, into a kernel with kvmclock disabled, causes random crashes
Summary: Rebooting a kernel with kvmclock enabled, into a kernel with kvmclock disable...
Alias: None
Product: Red Hat Enterprise Linux 5
Classification: Red Hat
Component: kvm
Version: 5.5
Hardware: All
OS: Linux
Target Milestone: rc
: ---
Assignee: Glauber Costa
QA Contact: Virtualization Bugs
Depends On: 588884
Blocks: Rhel5KvmTier1 588877
TreeView+ depends on / blocked
Reported: 2010-05-04 18:40 UTC by Glauber Costa
Modified: 2013-01-09 22:32 UTC (History)
18 users (show)

Fixed In Version: kvm-83-185.el5
Doc Type: Bug Fix
Doc Text:
Clone Of: 588874
Last Closed: 2011-01-13 23:35:24 UTC
Target Upstream Version:

Attachments (Terms of Use)

System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2011:0028 0 normal SHIPPED_LIVE Low: kvm security and bug fix update 2011-01-13 11:03:39 UTC

Description Glauber Costa 2010-05-04 18:40:27 UTC
+++ This bug was initially created as a clone of Bug #588874 +++

Description of problem:

Right now, if we boot into a kernel with kvmclock eanbled, and then reboot into a kernel with kvmclock disabled (rebooting with no-kvmclock kernel option is enough), we'll see the second kernel crash with random memory corruption.

This indicates that kvmclock is still writing to the old memory location,
which will now contain something else entirely.

Version-Release number of selected component (if applicable):
all, including upstream

How reproducible:


Steps to Reproduce:
1. boot a kernel with kvmclock enabled
2. reboot
3. pause grub in the OS selection screen, edit parameters, and remove kvmclock
Actual results:


Expected results:


Comment 1 Zachary Amsden 2010-06-22 21:00:50 UTC
Hasn't this already been fixed?  I remember reviewing the patches.

Comment 2 Glauber Costa 2010-06-23 13:25:01 UTC
My bad, forgot to send the patches for 5.5 Just did it for 6.
I am sending it within the hour.

Comment 7 Mike Cao 2010-11-03 07:47:52 UTC
# uname -r 
# rpm -q kvm

Verified with Fedora 13 and rhel5.5 64 bit guest by using the steps in comment #0,
This issue has already been fixed.

Comment 10 errata-xmlrpc 2011-01-13 23:35:24 UTC
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.


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