Re: [PATCHv7 00/14] mm, x86/cc: Implement support for unaccepted memory

Borislav Petkov
2022-07-19T21:23:36Z

On Tue, Jul 19, 2022 at 10:45:06PM +0200, Ard Biesheuvel wrote:
> So let's define a way for the EFI stub to signal to the firmware
> (before EBS()) that it will take control of accepting memory. The
> 'bootloader that calls EBS()' case can invent something along the
> lines of what has been proposed in this thread to infer the
> capabilities of the kernel (and decide what to signal to the
> firmware). But we have no need for this additional complexity on
> Linux.

To tell you the truth, I've been perusing this thread from the sidelines
and am wondering why does this need this special dance at all?

If EFI takes control of accepting memory, then when the guest kernel
boots, it'll find all memory accepted and not do anything.

If EFI doesn't accept memory, then the guest kernel will boot and do the
accepting itself.

So either I'm missing something or we're overengineering this for no
good reason...

--
Regards/Gruss,
Boris.