Re: trace events

[Marek Bykowski <marek.bykowski@gmail.com>]

On Thu, 17 Nov 2022 16:50:56 -0800
Alison Schofield <alison.schofield@intel.com> wrote:

> There are a few patchsets under review that are using trace events
> in CXL. I'm working on one for CXL Poison Retrieval.
> 
> There is also tool support, the monitor patchset, making its way
> upstream for ndctl that uses the trace events.
> 
> I haven't looked at lttng.
> 
> Can you share more about your project?

Hi Alison,

There should be already plenty of tools using the trace events,
libtraceevent, libtrracefs and trace-cmd, lttng, but I guess
another one may be of use too. When do you think it should be out
for testing?

For the project, it is strictly secret, and I shouldn't reveal too
much publicly, as I was told at least, but what we do we basically
test a CXL root complex in RTL/verilog that instead of being synthesized,
gets compiled to a VCS sim (a simulator) that in turn gets
connected through the BFM (bus-function-model) to another simulator,
simics or qemu. The connection to another simulator is for having
the root complex to test it against something.

So to serve the purpose I need a good grip at what is happening at
a very low level, ideally with the CXL operation taken down to the
register access/mnemonics, especially throughout the enumeration
phase, which we think will the primary source of all the defects to be
caught up and fixed in RTL.

I hope our paths would cross at some point in which the HW will be
finding its way to Linux with all the support it requires.

Any tips/suggestions how I can use Linux for now effectively to
achieve my goals is highly appreciated.

Thanks,
Marek