Re: [PATCH v8 0/8] hmp, qmp: Add commands to introspect virtio devices

[Jonah Palmer]

On 11/5/21 03:26, Markus Armbruster wrote:

> Daniel P. Berrangé <berrange@redhat.com> writes:
>
> > On Wed, Oct 27, 2021 at 07:41:41AM -0400, Jonah Palmer wrote:
> > > This series introduces new QMP/HMP commands to dump the status of a
> > > virtio device at different levels.
> > >
> > > [Jonah: Rebasing previous patchset from Oct. 5 (v7). Original patches
> > >  are from Laurent Vivier from May 2020.
> > >
> > >  Rebase from v7 to v8 includes an additional assert to make sure
> > >  we're not returning NULL in virtio_id_to_name(). Rebase also
> > >  includes minor additions/edits to qapi/virtio.json.]
> > >
> > > 1. Main command
> > >
> > > HMP Only:
> > >
> > >     virtio [subcommand]
> > >
> > >     Example:
> > >
> > >         List all sub-commands:
> > >
> > >         (qemu) virtio
> > >         virtio query  -- List all available virtio devices
> > >         virtio status path -- Display status of a given virtio device
> > >         virtio queue-status path queue -- Display status of a given virtio queue
> > >         virtio vhost-queue-status path queue -- Display status of a given vhost queue
> > >         virtio queue-element path queue [index] -- Display element of a given virtio queue
> > >         
> > I don't see a compelling reason why these are setup as sub-commands
> > under a new "virtio" top level. This HMP approach and the QMP 'x-debug-query'
> > naming just feels needlessly different from the current QEMU practices.
> >
> > IMHO they should just be "info" subcommands for HMP. ie
> >
> >          info virtio  -- List all available virtio devices
> >          info virtio-status path -- Display status of a given virtio device
> >          info virtio-queue-status path queue -- Display status of a given virtio queue
> >          info virtio-vhost-queue-status path queue -- Display status of a given vhost queue
> >          info virtio-queue-element path queue [index] -- Display element of a given virtio queue
> >       
> I agree with Dan (but I'm not the maintainer).
>     
I do like this format a bit better than Dave's recommendation. Feels a bit
more intuitive to understand what the commands should be doing, but I'm
not sure if this is just because I'm new to these things.

I'd like to format it like above if that's okay.
> > While the corresponding QMP commands ought to be
> >
> >          x-query-virtio
> >          x-query-virtio-status
> >          x-query-virtio-queue-status
> >          x-query-virtio-vhost-queue-status
> >          x-query-virtio-queue-element
> >       
> I agree with Dan (and I am the maintainer).
>
> The x- is not strictly required anymore (see commit a3c45b3e62 'qapi:
> New special feature flag "unstable"').  I lean towards keeping it here,
> because we don't plan to stabilize these commands.
>     
Ok! I'll keep the 'x-' in and change them to the above.

Thank you for the comments!!

Jonah