Re: [Qemu-devel] [PATCH v4 13/54] plugin: add user-facing API

[Aaron Lindsay OS]

On Sep 06 20:31, Alex Bennée wrote:
> Aaron Lindsay OS <address@hidden> writes:
> 
> > One thing I would find useful is the ability to access register values
> > during an execution-time callback. I think the easiest way to do that
> > generically would be to expose them via the gdb functionality (like
> > Pavel's earlier patchset did [1]), though that (currently) limits you to
> > the general-purpose registers. Ideally it would be nice be able to
> > access other registers (i.e. floating-point, or maybe even system
> > registers), though those are more difficult to do generically.
> 
> ARM already has system register support via the gdbstub XML interface so
> it's certainly doable. The trick is how we do that in a probable way
> without leaking the gdb remote protocol into plugins (which is just very
> ugly).

What do you mean by "in a probable way"?

I agree that simply exposing the gdb interface does not seem like a
clean solution.

> > Perhaps if we added some sort of architectural-support checking for
> > individual plugins like I mentioned in another response to this
> > patchset, we could allow some limited architecture-specific
> > functionality in this vein? I confess I haven't thought through all the
> > ramifications of that yet, though.
> 
> I was wondering if exposing the Elf Type would be enough? It's portable
> enough that plugins should be able to work with it without defining our
> own architecture enumeration.

I can't think of a reason that wouldn't work, assuming you're referring
to exposing a value corresponding to the `e_machine` ELF header.

-Aaron