By looking at the dmesg on a i386 kvm guest with pvclock enabled, I noticed that we're registering the boot clock after primary and secondary clock are already registered, as part of the cpu identification code. This causes kvm to write data to a random memory area during guest's life.
I just posted it, definitely for 5.6. But maybe we should consider it for 5.5 post beta too. Fix is not hard and not invasive.
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.
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. http://rhn.redhat.com/errata/RHSA-2010-0178.html