2020-03-25 19:44:45

by Ross Philipson

[permalink] [raw]
Subject: [RFC PATCH 12/12] tpm: Allow locality 2 to be set when initializing the TPM for Secure Launch

The Secure Launch MLE environment uses PCRs that are only accessible from
the DRTM locality 2. By default the TPM drivers always initialize the
locality to 0. When a Secure Launch is in progress, initialize the
locality to 2.

Signed-off-by: Ross Philipson <[email protected]>
---
drivers/char/tpm/tpm-chip.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index 3d6d394a8661..e74860537252 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -23,6 +23,7 @@
#include <linux/major.h>
#include <linux/tpm_eventlog.h>
#include <linux/hw_random.h>
+#include <linux/slaunch.h>
#include "tpm.h"

DEFINE_IDR(dev_nums_idr);
@@ -34,12 +35,20 @@ dev_t tpm_devt;

static int tpm_request_locality(struct tpm_chip *chip)
{
- int rc;
+ int rc, locality;

if (!chip->ops->request_locality)
return 0;

- rc = chip->ops->request_locality(chip, 0);
+ if (slaunch_get_flags() & (SL_FLAG_ACTIVE|SL_FLAG_ARCH_TXT)) {
+ dev_dbg(&chip->dev, "setting TPM locality to 2 for MLE\n");
+ locality = 2;
+ } else {
+ dev_dbg(&chip->dev, "setting TPM locality to 0\n");
+ locality = 0;
+ }
+
+ rc = chip->ops->request_locality(chip, locality);
if (rc < 0)
return rc;

--
2.25.1