Comment 5 for bug 1581420

Hi Phillipp, I was looking over your backport today and have a few remarks to add:

xen/arch/x86/mm/guest_walk.c:

Your backport drops the two first hunks of the 4.3 patch but I think from manually looking at the code as it is (at least what we got in Trusty) they would fit. Of course with a bit of manually ignoring context.

xen/arch/x86/hvm/hvm.c:

I agree there is no handling of the 0x80000008 case there, yet. Probably need to figure out when that got added and for what reason. Looks to be restricting values returned by the generic cpuid call. So that might be necessary to add after the other changes done.

Last, could it be that v2 is not really the right patch? From the comment I would expect a hunk modifying xen/include/asm-x86/x86_32/page.h but that does not seem to be there. No need to update it, I can make the changes in my tree.