kexec regression since 4.9 caused by efi

[Matt Fleming]

On Thu, 09 Mar, at 12:53:36PM, Ard Biesheuvel wrote:
> 
> Hi Omar,
> 
> Thanks for tracking this down.
> 
> I wonder if this is an unintended side effect of the way we repurpose
> the EFI_MEMORY_RUNTIME attribute in efi_arch_mem_reserve(). AFAIUI,
> splitting memory map entries should only be necessary for regions that
> are not runtime memory regions to begin with, and so whether their
> virtual mapping address makes sense or not should be irrelevant.
> 
> Perhaps this only illustrates my lack of understanding of the x86 way
> of doing this, so perhaps Matt can shed some light on this?

Sorry for the delay.

Yes, Ard is correct. It's not necessary to split/reserve memory
regions that already have the EFI_MEMORY_RUNTIME attribute.