[POC] Get acpi table to limit memory scope chosen by KASLR to home SB when "movable_node" is specified

From: Chao Fan
Date: Thu Aug 03 2017 - 04:52:27 EST

Hi all,

Here is an issue about movable_node and KASLR.
Currently, KASLR works well with "mem=", by which we can limit the scope of
memory chosen by KASLR. But if we use "movable_node" independently without
"mem=", we don't know the scope of memory in the home SB, which will cause
the memory of hotplug SB may be chosen by KASLR.
To solve this problem, I want to do this job:
If "movable_node" is specified, try to get the acpi table and find the scope
of memory in home SB, then set "mem_limit".

The order of getting table is:
\-efi tables
\-rsdt or xsdt
\-acpi root table list
\-acpi srat mem affinity

I am not sure if it's OK for community.
If there are any problems, please let me know.
Any comments will be welcome.

Chao Fan