Re: [PATCH v2 2/2] crypto/ccp: Skip SNP_INIT if preparation fails

[Tom Lendacky <thomas.lendacky@amd.com>]

On 4/7/26 12:47, Tycho Andersen wrote:
> From: "Tycho Andersen (AMD)" <tycho@kernel.org>
> 
> During SNP_INIT, the firmware checks to see that the SNP enable bit is set
> on all CPUs. If snp_prepare() failed because not all CPUs were online,
> SNP_INIT will fail, so skip it.

This should probably be more generic and state that if snp_prepare()
fails for any reason then SNP_INIT will fail, so skip it.

> 
> Signed-off-by: Tycho Andersen (AMD) <tycho@kernel.org>
> ---
>  drivers/crypto/ccp/sev-dev.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
> index 939fa8aa155c..854263cbb256 100644
> --- a/drivers/crypto/ccp/sev-dev.c
> +++ b/drivers/crypto/ccp/sev-dev.c
> @@ -1374,7 +1374,9 @@ static int __sev_snp_init_locked(int *error, unsigned int max_snp_asid)
>  		return -EOPNOTSUPP;
>  	}
>  
> -	snp_prepare();
> +	rc = snp_prepare();
> +	if (rc < 0)

If we are expecting that success only ever returns 0, I would say this
should just be "if (rc)".

Thanks,
Tom

> +		return rc;
>  
>  	/*
>  	 * Starting in SNP firmware v1.52, the SNP_INIT_EX command takes a list