Re: [PATCHv2 16/29] x86/boot: Add a trampoline for booting APs via firmware handoff

From: Borislav Petkov
Date: Fri Feb 04 2022 - 08:50:14 EST


On Fri, Feb 04, 2022 at 03:27:19AM -0800, Kuppuswamy, Sathyanarayanan wrote:
> trampoline_start and sev_es_trampoline_start are not mutually exclusive.
> Both are
> used in arch/x86/kernel/sev.c.

I know - I've asked Jörg to have a look here.

> But trampoline_start64 can be removed and replaced with trampoline_start.
> But using
> _*64 suffix makes it clear that is used for 64 bit(CONFIG_X86_64).
>
> Adding it for clarity seems to be fine to me.

Does it matter if the start IP is the same for all APs? Or do will there
be a case where you have some APs starting from the 32-bit trampoline
and some from the 64-bit one, on the same system? (that would be weird
but what do I know...)

--
Regards/Gruss,
Boris.

https://people.kernel.org/tglx/notes-about-netiquette