Hi, This patch fixes a (hopefully) rare-occurring problem causing memory corruption in 64 bit guests (and assertion failures in debug build xen). On a pagefault, set_l{3,4}e's resync_all was able to give write access to a page in the guest still not shadowed. This fix should be applied to Xen-3.3 as well. Signed-off-by: Gianluca Guida