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[v2,01/13] docs: Warn about incomplete vtpmmgr TPM 2.0 support

Message ID 20210506135923.161427-2-jandryuk@gmail.com (mailing list archive)
State New
Headers show
Series vtpmmgr: Some fixes - still incomplete | expand

Commit Message

Jason Andryuk May 6, 2021, 1:59 p.m. UTC
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(+)
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Patch

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