hm, i just found a failing 64-bit .config while testing your CPA 
patchset:

 [    1.916541] CPA mapping 4k 0 large 2048 gb 0 x 0[0-0] miss 0
 [    1.919874] Unable to handle kernel paging request at 000000000335aea8 RIP:
 [    1.919874]  [<ffffffff8021d2d3>] change_page_attr+0x3/0x61
 [    1.919874] PGD 0
 [    1.919874] Oops: 0000 [1]
 [    1.919874] CPU 0

config and full crash.log attached. Fully reproducible. I've also pushed 
out the current x86.git with the new CPA bits included.

	Ingo