Re: [PATCH] x86/boot/compressed/head_64.S: Cleanup SEV-related comments

[Tom Lendacky]

On 6/19/26 23:37, Borislav Petkov wrote:
> From: "Borislav Petkov (AMD)" <bp@xxxxxxxxx>
> 
> Move the comment about setting the encryption mask above the line which
> does that and, especially, inside the ifdeffery, where it belongs.
> 
> Move comments ontop of the code lines they refer to and not on the
> side, which impairs readability.
> 
> No functional changes.
> 
> Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>

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

> ---
>  arch/x86/boot/compressed/head_64.S | 18 +++++++++++-------
>  1 file changed, 11 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
> index d9dab940ff62..1aca51390f73 100644
> --- a/arch/x86/boot/compressed/head_64.S
> +++ b/arch/x86/boot/compressed/head_64.S
> @@ -172,19 +172,23 @@ SYM_FUNC_START(startup_32)
>   /*
>    * Build early 4G boot pagetable
>    */
> -	/*
> -	 * If SEV is active then set the encryption mask in the page tables.
> -	 * This will ensure that when the kernel is copied and decompressed
> -	 * it will be done so encrypted.
> -	 */
>  	xorl	%edx, %edx
>  #ifdef	CONFIG_AMD_MEM_ENCRYPT
>  	call	get_sev_encryption_bit
>  	xorl	%edx, %edx
>  	testl	%eax, %eax
>  	jz	1f
> -	subl	$32, %eax	/* Encryption bit is always above bit 31 */
> -	bts	%eax, %edx	/* Set encryption mask for page tables */
> +
> +	/* Encryption bit is always above bit 31 */
> +	subl	$32, %eax
> +
> +	/*
> +	 * If SEV is active then set the encryption mask in the page tables.
> +	 * This will ensure that when the kernel is copied and decompressed it
> +	 * will be done so encrypted.
> +	 */
> +	bts	%eax, %edx
> +
>  	/*
>  	 * Set MSR_AMD64_SEV_ENABLED_BIT in sev_status so that
>  	 * startup32_check_sev_cbit() will do a check. sev_enable() will