On May 6, 2021, at 10:00, Jason Andryuk <jandryuk@gmail.com> 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@gmail.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
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