[PATCH v1 2/2] crypto/ccp: Skip SNP_INIT if preparation fails

[Tycho Andersen <tycho@kernel.org>]

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.

Signed-off-by: Tycho Andersen (AMD) <tycho@kernel.org>
---
 drivers/crypto/ccp/sev-dev.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 939fa8aa155c..1fc7ee432e28 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -1374,7 +1374,10 @@ static int __sev_snp_init_locked(int *error, unsigned int max_snp_asid)
 		return -EOPNOTSUPP;
 	}
 
-	snp_prepare();
+	if (snp_prepare() < 0) {
+		dev_dbg(sev->dev, "SNP preparation failed, are all CPUs online?\n");
+		return -EOPNOTSUPP;
+	}
 
 	/*
 	 * Starting in SNP firmware v1.52, the SNP_INIT_EX command takes a list
-- 
2.53.0