Re: [PATCH 0/3] Resolve problems with kexec identity mapping

From: Borislav Petkov
Date: Tue Jul 09 2024 - 06:32:31 EST


On Mon, Jul 08, 2024 at 11:05:29PM +0200, Ard Biesheuvel wrote:
> The EFI config table array can grow and shrink at boot time, which is
> why it is a separate allocation, as this allows it to be realloc()'ed.
> This means any bootloader that intends to map the primary EFI table
> should also map the EFI config table array, which may be elsewhere
> entirely.

Yap, that rings a bell from a past thread.

> So regardless of how we fix any SEV-guest specific issues, we should
> ensure that kexec infrastructure creates the mappings of the EFI
> system table and the EFI config table array upfront.

Because code in the kernel relies on the presence of those so those should be
mapped automatically and unconditionally?

Or?

As long as we put that somewhere as the thing we do by default, sure, I'm
game.

--
Regards/Gruss,
Boris.

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