Re: [PATCH v4 00/11] x86: Refactor and consolidate startup code

[Borislav Petkov]

On Thu, Apr 10, 2025 at 03:41:18PM +0200, Ard Biesheuvel wrote:
> Ard Biesheuvel (11):
>   x86/asm: Make rip_rel_ptr() usable from fPIC code
>   x86/boot: Move the early GDT/IDT setup code into startup/
>   x86/boot: Move early kernel mapping code into startup/
>   x86/boot: Drop RIP_REL_REF() uses from early mapping code
>   x86/boot: Move early SME init code into startup/
>   x86/boot: Drop RIP_REL_REF() uses from SME startup code
>   x86/sev: Prepare for splitting off early SEV code
>   x86/sev: Split off startup code from core code
>   x86/boot: Move SEV startup code into startup/
>   x86/boot: Drop RIP_REL_REF() uses from early SEV code
>   x86/asm: Retire RIP_REL_REF()
> 
>  arch/x86/boot/compressed/Makefile                          |    2 +-
>  arch/x86/boot/compressed/sev.c                             |   17 +-
>  arch/x86/boot/startup/Makefile                             |   16 +
>  arch/x86/boot/startup/gdt_idt.c                            |   84 +
>  arch/x86/boot/startup/map_kernel.c                         |  225 +++
>  arch/x86/{coco/sev/shared.c => boot/startup/sev-shared.c}  |  375 +----
>  arch/x86/boot/startup/sev-startup.c                        | 1395 ++++++++++++++++
>  arch/x86/{mm/mem_encrypt_identity.c => boot/startup/sme.c} |   19 +-
>  arch/x86/coco/sev/Makefile                                 |   19 -
>  arch/x86/coco/sev/core.c                                   | 1726 ++++----------------
>  arch/x86/include/asm/asm.h                                 |    5 -
>  arch/x86/include/asm/coco.h                                |    2 +-
>  arch/x86/include/asm/mem_encrypt.h                         |    2 +-
>  arch/x86/include/asm/sev-internal.h                        |  112 ++
>  arch/x86/include/asm/sev.h                                 |   37 +
>  arch/x86/kernel/head64.c                                   |  285 +---
>  arch/x86/mm/Makefile                                       |    6 -
>  17 files changed, 2208 insertions(+), 2119 deletions(-)
>  create mode 100644 arch/x86/boot/startup/gdt_idt.c
>  create mode 100644 arch/x86/boot/startup/map_kernel.c
>  rename arch/x86/{coco/sev/shared.c => boot/startup/sev-shared.c} (78%)
>  create mode 100644 arch/x86/boot/startup/sev-startup.c
>  rename arch/x86/{mm/mem_encrypt_identity.c => boot/startup/sme.c} (97%)
>  create mode 100644 arch/x86/include/asm/sev-internal.h

Looks sensible at a glance. The devil's in the detail with that stuff,
ofc, so we will have to test it with as many toolchains and usage
scenarios as possible.

Thx.