Re: [PATCH V3 2/4] crypto: ccp - Move SEV_INIT retry for corrupted data

[Sean Christopherson]

On Tue, Nov 02, 2021, Peter Gonda wrote:
> This change moves the data corrupted retry of SEV_INIT into the

Use imperative mood.

> __sev_platform_init_locked() function. This is for upcoming INIT_EX
> support as well as helping direct callers of
> __sev_platform_init_locked() which currently do not support the
> retry.
> 
> Signed-off-by: Peter Gonda <pgonda@xxxxxxxxxx>
> Reviewed-by: Marc Orr <marcorr@xxxxxxxxxx>
> Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
> Acked-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
> Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
> Cc: Brijesh Singh <brijesh.singh@xxxxxxx>
> Cc: Marc Orr <marcorr@xxxxxxxxxx>
> Cc: Joerg Roedel <jroedel@xxxxxxx>
> Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> Cc: David Rientjes <rientjes@xxxxxxxxxx>
> Cc: John Allen <john.allen@xxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Cc: linux-crypto@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> ---
>  drivers/crypto/ccp/sev-dev.c | 24 ++++++++++++------------
>  1 file changed, 12 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
> index ec89a82ba267..e4bc833949a0 100644
> --- a/drivers/crypto/ccp/sev-dev.c
> +++ b/drivers/crypto/ccp/sev-dev.c
> @@ -267,6 +267,18 @@ static int __sev_platform_init_locked(int *error)
>  	}
>  
>  	rc = __sev_do_cmd_locked(SEV_CMD_INIT, &data, error);
> +	if (rc && *error == SEV_RET_SECURE_DATA_INVALID) {

There are no guarantees that @error is non-NULL as this is reachable via an
exported function, sev_platform_init().  Which ties in with my complaints in the
previous patch that the API is a bit of a mess.

> +		/*
> +		 * INIT command returned an integrity check failure
> +		 * status code, meaning that firmware load and
> +		 * validation of SEV related persistent data has
> +		 * failed and persistent state has been erased.
> +		 * Retrying INIT command here should succeed.
> +		 */
> +		dev_dbg(sev->dev, "SEV: retrying INIT command");
> +		rc = __sev_do_cmd_locked(SEV_CMD_INIT, &data, error);
> +	}
> +
>  	if (rc)
>  		return rc;
>  
> @@ -1091,18 +1103,6 @@ void sev_pci_init(void)
>  
>  	/* Initialize the platform */
>  	rc = sev_platform_init(&error);
> -	if (rc && (error == SEV_RET_SECURE_DATA_INVALID)) {
> -		/*
> -		 * INIT command returned an integrity check failure
> -		 * status code, meaning that firmware load and
> -		 * validation of SEV related persistent data has
> -		 * failed and persistent state has been erased.
> -		 * Retrying INIT command here should succeed.
> -		 */
> -		dev_dbg(sev->dev, "SEV: retrying INIT command");
> -		rc = sev_platform_init(&error);
> -	}
> -
>  	if (rc) {
>  		dev_err(sev->dev, "SEV: failed to INIT error %#x, rc %d\n",
>  			error, rc);
> -- 
> 2.33.1.1089.g2158813163f-goog
>