On Mon, Sep 10, 2018 at 10:18:22AM -0700, Tadeusz Struk wrote: > The TCG SAPI specification [1] defines a set of functions, which allow > applications to use the TPM device in either blocking or non-blocking fashion. > Each command defined by the specification has a corresponding > Tss2_Sys_<COMMAND>_Prepare() and Tss2_Sys_<COMMAND>_Complete() call, which > together with Tss2_Sys_ExecuteAsync() is designed to allow asynchronous > mode of operation. Currently the TPM driver supports only blocking calls, > which doesn't allow asynchronous IO operations. > This patch changes it and adds support for nonblocking write and a new poll > function to enable applications, which want to take advantage of this feature. > The new functionality can be tested using standard TPM tools implemented > in [2], together with modified TCTI from [3], and an example application > by Philip Tricca [4]. Here is a short description from Philip: > > "The example application `glib-tss2-event` uses a glib main event loop > to create an RSA 2048 primary key in the TPM2 NULL hierarchy while > using a glib timer event to time the operation. A GSource object is > used to generate an event when the FD underlying the tss2 function > call has data ready. While the application waits for an event indicating > that the CreatePrimary operation is complete, it counts timer events > that occur every 100ms. Once the CreatePrimary operation completes the > number of timer events that occurred is used to make a rough calculation > of the elapsed time. This value is then printed to the console. > This takes ~300 lines of C code and requires no management or > synchronization of threads. The glib GMainContext is "just a poll() > loop" according to the glib documentation here: > > https://developer.gnome.org/programming-guidelines/stable/main-contexts.html.en > > and so supporting 'poll' is the easiest way to integrate with glib / > gtk+. This is true of any other event system that relies on 'poll' > instead of worker threads." > > [1] https://trustedcomputinggroup.org/wp-content/uploads/TSS_SAPI_Version-1.1_Revision-22_review_030918.pdf > [2] https://github.com/tpm2-software/tpm2-tools > [3] https://github.com/tstruk/tpm2-tss/tree/async > [4] https://github.com/flihp/glib-tss2-async-example I tried to test this but I get 404 from https://github.com/tstruk/tpm2-tss/tree/async /Jarkko
