Re: [PATCH v8 1/4] crypto: ccp - Name -1 return value as SEV_RET_NO_FW_CALL

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

On 11/4/22 18:00, Dionna Glaze wrote:
> From: Peter Gonda <pgonda@google.com>
> 
> The PSP can return a "firmware error" code of -1 in circumstances where
> the PSP is not actually called. To make this protocol unambiguous, we
> add a constant naming the return value.
> 
> Cc: Thomas Lendacky <Thomas.Lendacky@amd.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Joerg Roedel <jroedel@suse.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Andy Lutomirsky <luto@kernel.org>
> Cc: John Allen <john.allen@amd.com>
> Cc: Herbert Xu <herbert@gondor.apana.org.au>
> Cc: "David S. Miller" <davem@davemloft.net>
> 
> Signed-off-by: Peter Gonda <pgonda@google.com>
> Signed-off-by: Dionna Glaze <dionnaglaze@google.com>

Looks like you missed my Reviewed-by: from an earlier version, so...

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

> ---
>   drivers/crypto/ccp/sev-dev.c | 2 +-
>   include/uapi/linux/psp-sev.h | 7 +++++++
>   2 files changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
> index 06fc7156c04f..97eb3544ab36 100644
> --- a/drivers/crypto/ccp/sev-dev.c
> +++ b/drivers/crypto/ccp/sev-dev.c
> @@ -444,7 +444,7 @@ static int __sev_platform_init_locked(int *error)
>   {
>   	struct psp_device *psp = psp_master;
>   	struct sev_device *sev;
> -	int rc = 0, psp_ret = -1;
> +	int rc = 0, psp_ret = SEV_RET_NO_FW_CALL;
>   	int (*init_function)(int *error);
>   
>   	if (!psp || !psp->sev_data)
> diff --git a/include/uapi/linux/psp-sev.h b/include/uapi/linux/psp-sev.h
> index 91b4c63d5cbf..1ad7f0a7e328 100644
> --- a/include/uapi/linux/psp-sev.h
> +++ b/include/uapi/linux/psp-sev.h
> @@ -36,6 +36,13 @@ enum {
>    * SEV Firmware status code
>    */
>   typedef enum {
> +	/*
> +	 * This error code is not in the SEV spec but is added to convey that
> +	 * there was an error that prevented the SEV Firmware from being called.
> +	 * This is (u32)-1 since the firmware error code is represented as a
> +	 * 32-bit integer.
> +	 */
> +	SEV_RET_NO_FW_CALL = 0xffffffff,
>   	SEV_RET_SUCCESS = 0,
>   	SEV_RET_INVALID_PLATFORM_STATE,
>   	SEV_RET_INVALID_GUEST_STATE,