On Wed, Jul 16, 2025 at 11:44:02AM -0700, Randy Dunlap wrote: > (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 > Thank you for reviewing this (especially given how bad shape it was)! BR, Jarkko
