crypto: ccp - Add a quirk to firmware update

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>

diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index 9f588c9..b292641 100644 (file)
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -744,6 +744,11 @@ 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;
@@ -776,6 +781,14 @@ 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
@@ -1285,8 +1298,7 @@ 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();
 
        /* If an init_ex_path is provided rely on INIT_EX for PSP initialization