[PATCH v3 1/4] ccp: Name -1 return value as SEV_RET_NO_FW_CALL

From: Dionna Glaze
Date: Fri Oct 21 2022 - 13:00:13 EST


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.

From: Peter Gonda <pgonda@xxxxxxxxxx>
Cc: Thomas Lendacky <Thomas.Lendacky@xxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Joerg Roedel <jroedel@xxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Andy Lutomirsky <luto@xxxxxxxxxx>

Signed-off-by: Dionna Glaze <dionnaglaze@xxxxxxxxxx>
---
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..fb61e083d42e 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 part of EXIT_INFO_2 is
+ * the lower 32 bits.
+ */
+ SEV_RET_NO_FW_CALL = 0xffffffff,
SEV_RET_SUCCESS = 0,
SEV_RET_INVALID_PLATFORM_STATE,
SEV_RET_INVALID_GUEST_STATE,
--
2.38.0.135.g90850a2211-goog