Re: [PATCH] tpm: add support for nonblocking operation

[Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>]

On Thu, Jul 05, 2018 at 04:15:06PM -0700, flihp wrote:
> Thanks for reviewing the patch Jarkko. While you're doing that I took
> some time to hack up code to demonstrate the utility of supporting this
> feature. The code can be found here:
> 
> https://github.com/flihp/glib-tss2-async-example
> 
> In short, 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.
> 
> I've tested this against the userspace resource management daemon (which
> supports 'poll') as well as the kernel interface using Tadeusz's patch
> currently under review here. If / when this gets merged feel free to add
> a "tested-by" line for myself:
> Tested-by: Philip Tricca <philip.b.tricca@intel.com>

I see the value now. I'll test this at early August when I'm back from
my leave.

Noticed now that the whole patch should be reposted because CC is missing
linux-kernel and linux-security-module (maybe with a link to your test
application in the cover letter).

/Jarkko