Re: [PATCH] x86/hyperv: add noop functions to x86_init mpparse functions

[Dave Hansen]

On 6/2/23 05:41, Saurabh Sengar wrote:
> In !ACPI system, there is no way to disable CONFIG_X86_MPPARSE.
> When CONFIG_X86_MPPARSE is enabled for VTL2, the kernel will
> scan low memory looking for MP tables. Don't allow this, because
> low memory is controlled by VTL0 and may contain actual valid
> tables for VTL0, which can confuse the VTL2 kernel.

Do you folks have a writeup of this VTL* setup anywhere?  I'm struggling
to grasp why VTL0 and VTL2 share the same address space and why they
would get confused by each other's data structures.

$ grep -r VTL[02] Documentation/
$

Either way, this is way better than the #ifdefs.  But the changelog is
kinda just gibberish to me.