Re: [PATCH v7 2/9] x86/startup_64: Defer assignment of 5-level paging global variables

[Borislav Petkov]

On Tue, Feb 27, 2024 at 04:19:10PM +0100, Ard Biesheuvel wrote:
> From: Ard Biesheuvel <ardb@xxxxxxxxxx>
> 
> Assigning the 5-level paging related global variables from the earliest
> C code using explicit references that use the 1:1 translation of memory
> is unnecessary, as the startup code itself does not rely on them to
> create the initial page tables, and this is all it should be doing. So
> defer these assignments to the primary C entry code that executes via
> the ordinary kernel virtual mapping.
> 
> Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
> ---
>  arch/x86/include/asm/pgtable_64_types.h |  2 +-
>  arch/x86/kernel/head64.c                | 44 +++++++-------------
>  2 files changed, 15 insertions(+), 31 deletions(-)

Reviewed-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>

Those should probably be tested on a 5level machine, just in case.

Thx.

-- 
Regards/Gruss,
    Boris.

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