Re: Making QEMU easier for management tools and applications

[Kevin Wolf]

Am 27.01.2020 um 21:29 hat Dr. David Alan Gilbert geschrieben:
> * Kevin Wolf (address@hidden) wrote:
> > A command history already exists for qmp-shell. It's better than bash
> > because it doesn't mix QMP history with whatever else I do on my
> > computer.
> > 
> > Autocomplete in qmp-shell doesn't exist, as far as I know, but if
> > implemented, it could be a lot more useful than bash completion because
> > it could offer key completion based on the QMP schema.
> > 
> > This is in fact a big part of the problem that qmp-shell really needs to
> > solve before it can replace HMP: How to make writing commands at least
> > almost as simple as with HMP. If I can just press tab a few times to
> > cycle through the available options for the command, that would already
> > be a massive improvement over writing JSON manually (which you would
> > still have to do with your text-file based approach, without any
> > QMP-specific support).
> 
> Doing all that in a python process (i.e. an actual python shell with a
> bunch of qemu commands added) seems easyish.

It does. Polishing everything for the perfect experience could be a bit
more work, but just querying the schema and providing some
autocompletion from it sounds easy enough.

> > The other part that it needs to solve is how to be available by default
> > without specifying anything on the command line. Basically, if I press
> > Ctrl-Alt-2, I want to get to a monitor shell. If that shell is
> > implemented internally or by an external Python process, I don't mind.
> 
> That is a harder part. (I rarely use Ctrl-Alt-2 actually; I mostly
> use HMP on stdin).

I don't think it would be that hard, actually.

If you have a -qmp-shell option that takes a chardev and defaults to vc,
you've solved the part with both stdio and Ctrl-Alt-2. Now all you need
to do is launch the Python child process, pass it a pair of pipes for
communication and forward everything between the pipes and the chardev.

(That's the theory anyway.)

Kevin