Re: [PATCH v4 1/3] x86/boot: Drop unused sev_enable() fallback

Tom Lendacky
2025-09-11T21:35:32Z

On 9/9/25 03:06, Ard Biesheuvel wrote:
> From: Ard Biesheuvel <ardb@kernel.org>
>
> The misc.h header is not included by the EFI stub, which is the only C
> caller of sev_enable(). This means the fallback for cases where
> CONFIG_AMD_MEM_ENCRYPT is not set is never used, so it can be dropped.
>
> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>

> ---
> arch/x86/boot/compressed/misc.h | 11 -----------
> 1 file changed, 11 deletions(-)
>
> diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h
> index db1048621ea2..fd855e32c9b9 100644
> --- a/arch/x86/boot/compressed/misc.h
> +++ b/arch/x86/boot/compressed/misc.h
> @@ -152,17 +152,6 @@ bool insn_has_rep_prefix(struct insn *insn);
> void sev_insn_decode_init(void);
> bool early_setup_ghcb(void);
> #else
> -static inline void sev_enable(struct boot_params *bp)
> -{
> - /*
> - * bp->cc_blob_address should only be set by boot/compressed kernel.
> - * Initialize it to 0 unconditionally (thus here in this stub too) to
> - * ensure that uninitialized values from buggy bootloaders aren't
> - * propagated.
> - */
> - if (bp)
> - bp->cc_blob_address = 0;
> -}
> static inline void snp_check_features(void) { }
> static inline void sev_es_shutdown_ghcb(void) { }
> static inline bool sev_es_check_ghcb_fault(unsigned long address)