[PATCH v2 0/3] efistub/x86: Fix early SEV-SNP memory acceptance

From: Ard Biesheuvel
Date: Fri Apr 04 2025 - 04:30:03 EST


From: Ard Biesheuvel <ardb@xxxxxxxxxx>

This is a follow-up to [0]. Instead of avoiding memory acceptance from
the EFI stub altogether, switch to a separate API that can be
implemented by SEV-SNP without relying on the shared GHCB page, which
cannot be created yet when still executing in the firmware context with
the firmware's page tables.

[0] https://lore.kernel.org/all/20250325091614.1203411-2-ardb+git@xxxxxxxxxx/T/#u

Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>,
Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>,
Cc: Dionna Amalie Glaze <dionnaglaze@xxxxxxxxxx>,
Cc: Kevin Loughlin <kevinloughlin@xxxxxxxxxx>

Ard Biesheuvel (3):
x86/boot: Move accept_memory() into decompressor
x86/boot: Use separate API for memory acceptance in the EFI stub
x86/boot: Implement early memory acceptance for SEV-SNP

arch/x86/boot/compressed/mem.c | 47 +++++++++++++++-
arch/x86/boot/compressed/sev.c | 34 ++++++++++--
drivers/firmware/efi/libstub/efistub.h | 3 +-
drivers/firmware/efi/libstub/unaccepted_memory.c | 57 +++-----------------
drivers/firmware/efi/libstub/x86-stub.c | 41 ++++++++++++++
5 files changed, 124 insertions(+), 58 deletions(-)

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2.49.0.504.g3bcea36a83-goog