Clarification for patch 7

[Mario Smarduch <m.smarduch@samsung.com>]

Hi Christoffer, Marc -
   in stage2_dissolve_pmd() CONFIG_SMP is
unnecessary. At the time huge page is write protected,
until it faults and is cleared any page in the range
may be dirty not just the gpa access that caused the
fault.

The comment on another CPU is wrong, I
confused myself while testing it should not be possible for
another CPU to write to same PMD range while
another is handling its PMD fault. I ran a test with
only initrd which exposed an issue using my
test scenario, QEMU appears fine.

It also depends on user space if you first turn
on logging, do pre-copy then marking just the page
is enough. It's hard to interpret the API in this
case. It just says dirty pages since the last
call.

That patch could be resent without upsetting
the rest.

- Mario