Re: [PATCH v8 0/4] tpm: Preserve TPM measurement log across kexec (ppc64)

[Stefan Berger]

On 11/10/22 21:21, Coiby Xu wrote:
> Hi Michael,
>
> Could the PowerPC tree take this patch set which resolves a
> PowerVM/KVM-specific issue?

Michael has (shown me) an alternative approach that protects the already allocated memory to carry it across the kexec. This seems like a good and potentially better alternative, also from the perspective of the changes need, which is a lot less , and it's already used for other stuff as well.

   Stefan

> On Thu, Sep 01, 2022 at 05:46:06PM -0400, Stefan Berger wrote:
> > The of-tree subsystem does not currently preserve the IBM vTPM 1.2 and
> > vTPM 2.0 measurement logs across a kexec on PowerVM and PowerKVM. This
> > series fixes this for the kexec_file_load() syscall using the flattened
> > device tree (fdt) to carry the TPM measurement log's buffer across kexec.
> >
> >   Stefan
> >
> > v8:
> > - Added Jarkko's, Coiby's, and Rob's tags
> > - Rebase on v6.0-rc3 that absorbed 2 already upstreamed patches
> >
> > v7:
> > - Added Nageswara's Tested-by tags
> > - Added back original comment to inline function and removed Jarkko's R-b tag
> >
> > v6:
> > - Add __init to get_kexec_buffer as suggested by Jonathan
> > - Fixed issue detected by kernel test robot
> >
> > v5:
> > - Rebased on 1 more patch that would otherwise create merge conflicts
> >
> > v4:
> > - Rebased on 2 patches that would otherwise create merge conflicts;
> >   posting these patches in this series with several tags removed so
> >   krobot can test the series already
> > - Changes to individual patches documented in patch descripitons
> >
> > v3:
> > - Moved TPM Open Firmware related function to drivers/char/tpm/eventlog/tpm_of.c
> >
> > v2:
> > - rearranged patches
> > - fixed compilation issues for x86
> >
> > Palmer Dabbelt (1):
> >  drivers: of: kexec ima: Support 32-bit platforms
> >
> > Stefan Berger (3):
> >  tpm: of: Make of-tree specific function commonly available
> >  of: kexec: Refactor IMA buffer related functions to make them reusable
> >  tpm/kexec: Duplicate TPM measurement log in of-tree for kexec
> >
> > drivers/char/tpm/eventlog/of.c |  31 +--
> > drivers/of/kexec.c             | 336 ++++++++++++++++++++++++++++-----
> > include/linux/kexec.h          |   6 +
> > include/linux/of.h             |   9 +-
> > include/linux/tpm.h            |  36 ++++
> > kernel/kexec_file.c            |   6 +
> > 6 files changed, 346 insertions(+), 78 deletions(-)
> >
> >
> > base-commit: b90cb1053190353cc30f0fef0ef1f378ccc063c5
> > --
> > 2.35.1