On May 6, 2021, at 10:00, Jason Andryuk <jandryuk@xxxxxxxxx> wrote:
The vtpmmgr TPM 2.0 support is incomplete. Add a warning about that to
the documentation so others don't have to work through discovering it is
broken.
Signed-off-by: Jason Andryuk <jandryuk@xxxxxxxxx>
Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
docs/man/xen-vtpmmgr.7.pod | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/docs/man/xen-vtpmmgr.7.pod b/docs/man/xen-vtpmmgr.7.pod
index af825a7ffe..875dcce508 100644
--- a/docs/man/xen-vtpmmgr.7.pod
+++ b/docs/man/xen-vtpmmgr.7.pod
@@ -222,6 +222,17 @@ XSM label, not the kernel.
=head1 Appendix B: vtpmmgr on TPM 2.0
+=head2 WARNING: Incomplete - cannot persist data
+
+TPM 2.0 support for vTPM manager is incomplete. There is no support for
+persisting an encryption key, so vTPM manager regenerates primary and secondary
+key handles each boot.
+
+Also, the vTPM manger group command implementation hardcodes TPM 1.2 commands.
+This means running manage-vtpmmgr.pl fails when the TPM 2.0 hardware rejects
+the TPM 1.2 commands. vTPM manager with TPM 2.0 cannot create groups and
+therefore cannot persist vTPM contents.
+
=head2 Manager disk image setup:
The vTPM Manager requires a disk image to store its encrypted data. The image
--
2.30.2
Should SUPPORT.md also be updated?
Rich
