Charlie Jacobsen authored Feb 09, 2016 and Vikram Narayanan committed Oct 26, 2016

Map everything except the ioremap region as write back. ioremap
region is uncacheable. Only high 512 GBs are mapped to the first
512 GBs of guest physical.

No more dynamic build up of the guest virtual address space during
page walks. That code was just so damn messy.