Re: Plugin Memory Callback Debugging

[Aaron Lindsay via <qemu-devel@nongnu.org>]

On Nov 15 22:36, Alex Bennée wrote:
> Aaron Lindsay <aaron@os.amperecomputing.com> writes:
> > I believe the code *should* always reset `cpu->plugin_mem_cbs` to NULL at the
> > end of an instruction/TB's execution, so its not exactly clear to me how this
> > is occurring. However, I suspect it may be relevant that we are calling
> > `free_dyn_cb_arr()` because my plugin called `qemu_plugin_reset()`.
> 
> Hmm I'm going to have to remind myself about how this bit works.

When is it expected that cpu->plugin_mem_cbs is reset to NULL if it is
set for an instruction? Is it guaranteed it is reset by the end of the
tb? If I were to put an assertion in cpu_tb_exec() just after the call
to tcg_qemu_tb_exec(), should cpu->plugin_mem_cbs always be NULL there?

In my debugging, I *think* I'm seeing a tb set cpu->plugin_mem_cbs
for an instruction, and then not reset it to NULL. I'm wondering if its
getting optimized away or something, but want to make sure I've got my
assumptions correct about how this is intended to be working.

Thanks!

-Aaron