pte_clear() is defined in 2.6.9-55.EL as set_pte(...,0). This clears the upper word before the lower word which means for MFN>4G the PTE value is temporarily invalid as far as Xen's page type tracking is concerned because the P bit is set when the top bits are cleared: (XEN) mm.c:649:d25 Error getting mfn 1f20e (pfn 5555555555555555) from L1 entry 000000001f20e063 for dom25 (XEN) mm.c:3295:d25 ptwr_emulate: fixing up invalid PAE PTE 000000001f20e063 (XEN) printk: 4246 messages suppressed. etc. The fix is to define pte_clear to clear the lower word first http://xenbits.xensource.com/kernels/rhel4x.hg?rev/e2f1456ed7bb
Thanks for pointing out these bugs, Ian. This particular one already had a patch submitted internally on May 30th 2007, I assume that one is already in our tree. Chris, can this patch go into MODIFIED?
Rik, Yeah, this has now been committed to our internal CVS, so MODIFIED it is. Thanks for the bug report, Ian. Chris Lalancette
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 the 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/RHBA-2007-0791.html