Re: [patch v2] crypto: ccp - Fix SEV_VERSION_GREATER_OR_EQUAL

From: Lendacky, Thomas
Date: Mon Jul 15 2019 - 13:03:17 EST


On 7/12/19 3:41 PM, David Rientjes wrote:
> SEV_VERSION_GREATER_OR_EQUAL() will fail if upgrading from 2.2 to 3.1, for
> example, because the minor version is not equal to or greater than the
> major.
>
> Fix this and move to a static inline function for appropriate type
> checking.
>
> Fixes: edd303ff0e9e ("crypto: ccp - Add DOWNLOAD_FIRMWARE SEV command")
> Reported-by: Cfir Cohen <cfir@xxxxxxxxxx>
> Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>

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

> ---
> v2: no need to check api_major >= maj after checking api_major > maj
> per Thomas
>
> drivers/crypto/ccp/psp-dev.c | 19 ++++++++++++-------
> 1 file changed, 12 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
> --- a/drivers/crypto/ccp/psp-dev.c
> +++ b/drivers/crypto/ccp/psp-dev.c
> @@ -24,10 +24,6 @@
> #include "sp-dev.h"
> #include "psp-dev.h"
>
> -#define SEV_VERSION_GREATER_OR_EQUAL(_maj, _min) \
> - ((psp_master->api_major) >= _maj && \
> - (psp_master->api_minor) >= _min)
> -
> #define DEVICE_NAME "sev"
> #define SEV_FW_FILE "amd/sev.fw"
> #define SEV_FW_NAME_SIZE 64
> @@ -47,6 +43,15 @@ MODULE_PARM_DESC(psp_probe_timeout, " default timeout value, in seconds, during
> static bool psp_dead;
> static int psp_timeout;
>
> +static inline bool sev_version_greater_or_equal(u8 maj, u8 min)
> +{
> + if (psp_master->api_major > maj)
> + return true;
> + if (psp_master->api_major == maj && psp_master->api_minor >= min)
> + return true;
> + return false;
> +}
> +
> static struct psp_device *psp_alloc_struct(struct sp_device *sp)
> {
> struct device *dev = sp->dev;
> @@ -588,7 +593,7 @@ static int sev_ioctl_do_get_id2(struct sev_issue_cmd *argp)
> int ret;
>
> /* SEV GET_ID is available from SEV API v0.16 and up */
> - if (!SEV_VERSION_GREATER_OR_EQUAL(0, 16))
> + if (!sev_version_greater_or_equal(0, 16))
> return -ENOTSUPP;
>
> if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
> @@ -651,7 +656,7 @@ static int sev_ioctl_do_get_id(struct sev_issue_cmd *argp)
> int ret;
>
> /* SEV GET_ID available from SEV API v0.16 and up */
> - if (!SEV_VERSION_GREATER_OR_EQUAL(0, 16))
> + if (!sev_version_greater_or_equal(0, 16))
> return -ENOTSUPP;
>
> /* SEV FW expects the buffer it fills with the ID to be
> @@ -1053,7 +1058,7 @@ void psp_pci_init(void)
> psp_master->sev_state = SEV_STATE_UNINIT;
> }
>
> - if (SEV_VERSION_GREATER_OR_EQUAL(0, 15) &&
> + if (sev_version_greater_or_equal(0, 15) &&
> sev_update_firmware(psp_master->dev) == 0)
> sev_get_api_version();
>
>