On 8/3/22 20:02, Jarkko Sakkinen wrote:
From: Jarkko Sakkinen <jarkko@xxxxxxxxxxx>
SEV-SNP does not initialize to a legit state, unless the firmware is
loaded twice, when SEP API version < 1.43, and the firmware is updated
to a later version. Because of this user space needs to work around
this with "rmmod && modprobe" combo. Fix this by implementing the
workaround to the driver.
Reported-by: Harald Hoyer <harald@xxxxxxxxxxx>
Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxxx>
---
drivers/crypto/ccp/sev-dev.c | 22 +++++++++++++++++++---
1 file changed, 19 insertions(+), 3 deletions(-)
diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 799b476fc3e8..f2abb7439dde 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -1274,6 +1285,7 @@ void sev_pci_init(void)
{
struct sev_device *sev = psp_master->sev_data;
int error, rc;
+ int i;
if (!sev)
return;
@@ -1283,9 +1295,13 @@ void sev_pci_init(void)
if (sev_get_api_version())
goto err;
- if (sev_version_greater_or_equal(0, 15) &&
- sev_update_firmware(sev->dev) == 0)
- sev_get_api_version();
+ /*
+ * SEV-SNP does not work properly before loading the FW twice in the API
+ * versions older than SEV 1.43.
+ */
+ for (i = 0; i < sev_version_greater_or_equal(0, 15) + sev_version_less(1, 43); i++)
+ if (sev_update_firmware(sev->dev) == 0)
+ sev_get_api_version();
I prefer to have this logic in the sev_update_firmware() function.
And while the loop is correct, it isn't obvious. Something in
sev_update_firmware() that just does:
ret = sev_do_cmd(SEV_CMD_DOWNLOAD_FIRMWARE, data, &error);
if (!ret && sev_version_greater_or_equal(0, 15) && sev_version_less(1, 43))
ret = sev_do_cmd(SEV_CMD_DOWNLOAD_FIRMWARE, data, &error);
And place a comment before the second command that references the reason
for the second download.
Thanks,
Tom
