Re: [PATCH v13 01/13] x86/sev: Carve out and export SNP guest messaging init routines

[Christophe JAILLET]

Le 21/10/2024 à 07:51, Nikunj A Dadhania a écrit :
> Currently, the SEV guest driver is the only user of SNP guest messaging.
> All routines for initializing SNP guest messaging are implemented within
> the SEV guest driver. To add Secure TSC guest support, these initialization
> routines need to be available during early boot.
>
> Carve out common SNP guest messaging buffer allocations and message
> initialization routines to core/sev.c and export them. These newly added
> APIs set up the SNP message context (snp_msg_desc), which contains all the
> necessary details for sending SNP guest messages.
>
> At present, the SEV guest platform data structure is used to pass the
> secrets page physical address to SEV guest driver. Since the secrets page
> address is locally available to the initialization routine, use the cached
> address. Remove the unused SEV guest platform data structure.
>
> Signed-off-by: Nikunj A Dadhania <nikunj@xxxxxxx>
> Reviewed-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
> ---

...

> +static inline bool is_vmpck_empty(struct snp_msg_desc *mdesc)
> +{
> +	char zero_key[VMPCK_KEY_LEN] = {0};

Nitpick: I think this could be a static const.

> +
> +	if (mdesc->vmpck)
> +		return !memcmp(mdesc->vmpck, zero_key, VMPCK_KEY_LEN);
> +
> +	return true;
> +}

...