Re: [PATCH v3 3/5] x86: Call efi_memblock_x86_reserve_range() on native EFI platform only

From: Matt Fleming
Date: Wed Mar 26 2014 - 09:31:37 EST


On Wed, 26 Mar, at 01:22:49PM, Jan Beulich wrote:
> >>> On 26.03.14 at 14:00, <matt@xxxxxxxxxxxxxxxxx> wrote:
> >
> > This could do with a little bit more explanation. Why is it not
> > necessary to mark the EFI memory map that was passed to the kernel as
> > reserved in memblock?
>
> Because that's in memory Dom0 doesn't even see: The EFI memory
> map is visible to the hypervisor only.

So where does boot_params.efi_info.efi_memmap point?

If nowhere (i.e. it's NULL) that's no problem because memblock_reserve()
handles zero size regions just fine.

--
Matt Fleming, Intel Open Source Technology Center
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