Before 95f31f37c1 ("Merge 'dirty_memory_manager: simplify
region_group' from Avi Kivity"), we had two region_group
objects, one _real_region_group and another _virtual_region_group,
each with a set of "soft" and "hard" limits and related functions
and members.
In 95f31f37c1, we merged _real_region_group into _virtual_region_group,
but unfortunately the _real_region_group members received the "hard"
prefix when they got merged. This overloads the meaning of "hard" -
is it related to soft/hard limit or is it related to the real/virtual
distinction?
This patch applied some renaming to restore consistency. Anything
that came from _virtual_region_group now has "virtual" in its name.
Anything that came from _real_region_group now has "real" in its name.
The terms are still pretty bad but at least they are consistent.