(mostly nits, along with Paul's comments)
On 7/16/25 5:18 AM, Jarkko Sakkinen wrote:
> From: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxx>
>
> Provide a kernel command-line parameter named as `supplicant`, which
> contains a path to an TPM emulator binary. When defind, the kernel will
to a TPM
> launch the program during boot-time.
>
> This feature is most useful in feature testing e.g., in environments
testing, e.g.,
> where other means are not possible, such as CI runners. Its original use
> case highlights also quite well of its applicability for pre-production
> hardware: it was used to provide a TPM implemnentation for a RISC-V SoC
> running on FPGA with no TPM HW implementation at the time.
>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxx>
> ---
> Bumped into this in my archives so thought to make it available just in
> case anyone is interested.
> ---
> .../admin-guide/kernel-parameters.txt | 14 +++++
> drivers/char/tpm/tpm_vtpm_proxy.c | 51 +++++++++++++++++++
> 2 files changed, 65 insertions(+)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index f1f2c0874da9..e062de99480e 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -7230,6 +7230,20 @@
> defined by Trusted Computing Group (TCG) see
> https://trustedcomputinggroup.org/resource/pc-client-platform-tpm-profile-ptp-specification/
>
> + tpm_vtpm_proxy.supplicant= [TPM]
> + When defined, this field must contain a legit path to a
legitimate
or valid
> + program emulating a TPM chip, which will be started
> + during the driver initialization, thus providing a
> + mechanism for the user space have an emulated TPM from
> + the get go. Kernel prepares the process with a file
get-go.
or just don't use slang terms.
> + pre-opened file descriptor in the index 3 for
> + /dev/vtpmx.
> +
> + An emulator can optionally provide support for
> + localities by reacting to the vendor command defined
> + by the driver: 0x20001000. Its payload is a single
> + byte containing the new locality.
> +
> tp_printk [FTRACE]
> Have the tracepoints sent to printk as well as the
> tracing ring buffer. This is useful for early boot up
thanks.
--
~Randy
