Re: [PATCH v9 2/2] tpm: Add support for event log pointer found in TPM2 ACPI table

From: Stefan Berger
Date: Wed Jul 08 2020 - 10:17:24 EST


On 7/8/20 10:07 AM, Jarkko Sakkinen wrote:
On Tue, Jul 07, 2020 at 12:09:11AM -0400, Stefan Berger wrote:
On 7/7/20 12:03 AM, Jarkko Sakkinen wrote:
On Mon, Jul 06, 2020 at 11:08:12PM -0400, Stefan Berger wrote:
On 7/6/20 10:24 PM, Jarkko Sakkinen wrote:
On Mon, Jul 06, 2020 at 07:55:26PM -0400, Stefan Berger wrote:
On 7/6/20 7:09 PM, Jarkko Sakkinen wrote:
On Mon, Jul 06, 2020 at 02:19:53PM -0400, Stefan Berger wrote:
From: Stefan Berger <stefanb@xxxxxxxxxxxxx>

In case a TPM2 is attached, search for a TPM2 ACPI table when trying
to get the event log from ACPI. If one is found, use it to get the
start and length of the log area. This allows non-UEFI systems, such
as SeaBIOS, to pass an event log when using a TPM2.

Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
Do you think that QEMU with TPM 1.2 emulator turned on would be a viable
way to test this?
Yes.
Is the emulator bundled with QEMU or does it have to be installed
separately?
It has to be installed separately. On Fedora 31 it would just be a `sudo dnf
-y install swtpm-tools` and you should be good to go with libvirt /
virt-manager.
Is there some packaging for Debian/Ubuntu available?

So far may not be available yet. I had *experimented* with a PPA once:
https://launchpad.net/~stefanberger/+archive/ubuntu/swtpm-focal
There is a snap available:

name: swtpm-mvo
summary: Libtpms-based TPM emulator
publisher: Michael Vogt (mvo)
store-url: https://snapcraft.io/swtpm-mvo
license: unset
description: |
Libtpms-based TPM emulator with socket, character device, and Linux
CUSE interface.
commands:
- swtpm-mvo.swtpm
services:
swtpm-mvo.swtpm-sock: simple, enabled, active
snap-id: HNl1TwHRBk3OtXQ8OriRB93FDZ6vman7
tracking: latest/edge
refresh-date: today at 02:05 EEST
channels:
latest/stable: â
latest/candidate: â
latest/beta: 0.1.0 2019-07-26 (11) 3MB -
latest/edge: 0.1.0 2020-07-08 (75) 3MB -
installed: 0.1.0 (74) 3MB -

This is the version information:

â swtpm-mvo.swtpm --version
TPM emulator version 0.4.0, Copyright (c) 2014 IBM Corp.

However, if I try to run the first example from [*], I get:

â swtpm-mvo.swtpm socket --tpmstate dir=/tmp/mytpm1 \
--ctrl type=unixio,path=/tmp/mytpm1/swtpm-sock \
--log level=20
swtpm: Could not open UnixIO socket: No such file or directory


Did you create the directory '/tmp/mytpm1' ?


[*] https://www.qemu.org/docs/master/specs/tpm.html

/Jarkko