[PATCH AUTOSEL 5.15 02/21] crypto: ccp - Add a quirk to firmware update

[Sasha Levin <sashal@kernel.org>]

From: Jarkko Sakkinen <jarkko@profian.com>

[ Upstream commit b3b9fdf1a9be4266b01a2063b1f37cdc20806e3b ]

A quirk for fixing the committed TCB version, when upgrading from a
firmware version earlier than 1.50. This is a known issue, and the
documented workaround is to load the firmware twice.

Currently, this issue requires the  following workaround:

sudo modprobe -r kvm_amd
sudo modprobe -r ccp
sudo modprobe ccp
sudo modprobe kvm_amd

Implement this workaround inside kernel by checking whether the API
version is less than 1.50, and if so, download the firmware twice.
This addresses the TCB version issue.

Link: https://lore.kernel.org/all/de02389f-249d-f565-1136-4af3655fab2a@profian.com/
Reported-by: Harald Hoyer <harald@profian.com>
Signed-off-by: Jarkko Sakkinen <jarkko@profian.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/crypto/ccp/sev-dev.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 900727b5edda..999a8e38ffe0 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -555,6 +555,11 @@ static int sev_update_firmware(struct device *dev)
 	struct page *p;
 	u64 data_size;
 
+	if (!sev_version_greater_or_equal(0, 15)) {
+		dev_dbg(dev, "DOWNLOAD_FIRMWARE not supported\n");
+		return -1;
+	}
+
 	if (sev_get_firmware(dev, &firmware) == -ENOENT) {
 		dev_dbg(dev, "No SEV firmware file present\n");
 		return -1;
@@ -587,6 +592,14 @@ static int sev_update_firmware(struct device *dev)
 	data->len = firmware->size;
 
 	ret = sev_do_cmd(SEV_CMD_DOWNLOAD_FIRMWARE, data, &error);
+
+	/*
+	 * A quirk for fixing the committed TCB version, when upgrading from
+	 * earlier firmware version than 1.50.
+	 */
+	if (!ret && !sev_version_greater_or_equal(1, 50))
+		ret = sev_do_cmd(SEV_CMD_DOWNLOAD_FIRMWARE, data, &error);
+
 	if (ret)
 		dev_dbg(dev, "Failed to update SEV firmware: %#x\n", error);
 	else
@@ -1091,8 +1104,7 @@ 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)
+	if (sev_update_firmware(sev->dev) == 0)
 		sev_get_api_version();
 
 	/* Obtain the TMR memory area for SEV-ES use */
-- 
2.35.1