Re: [PATCH v7 05/35] monitor: minimal conversion of monitors to QOM

[Markus Armbruster <armbru@redhat.com>]

Daniel P. Berrangé <berrange@redhat.com> writes:

> This introduces abstract QOM type "monitor", with concrete subtypes
> "monitor-hmp" and "monitor-qmp". This is the bare minimum conversion
> of just the type declarations and replacing g_new/g_free with
> object_new/object_unref.
>
> Command line option "-monitor" now creates a "monitor-hmp" object
> "/objects/compat_monitorNNN" in addition to the character device
> "/chardevs/compat_monitorNNN". NNN counts up from zero.
>
> Exception: "-monitor chardev:ID" creates a "monitor-hmp" object
> "/objects/ID", and does not create a character device.
>
> "-qmp" and "-qmp-pretty" work the same, except they create a
> "monitor-qmp" object.
>
> "-mon" now creates either a "monitor-hmp" or "monitor-qmp" object
> "/objects/ID" if the option argument provides an ID, else
> "/objects/compat_monitorNNN".
>
> "-gdbstub" and "-serial mon:..." now create a "monitor-hmp" object
> "/objects/compat_monitorNNN".
>
> Note that the object's name in "/objects/" matches the QemuOpts ID when
> it exists.  The only cases where it doesn't exist are "-mon" without ID,
> "-gdbstub" and "-serial mon:".
>
> A future patch will make "monitor-hmp" and "monitor-qmp" work with
> "-object" and "object-add".
>
> Note: there is a slight change in the NNN values assigned. The old
> code would increment the counter for every monitor added, regardless
> of whether it needed a "compat_monitorNNN" ID assignment. Now it is
> only incremented when an automatic ID assigned is needed, from any
> of -mon, -gdbstub or -serial.

This isn't quite right.  The old code increments the counter for every
monitor added with monitor_parse(), i.e. the monitors added with
-monitor, -qmp, -qmp-pretty, and most default monitors.  -mon, -serial
mon:..., and -gdbstub don't use monitor_parse().

If we don't need a respin (which seems likely), I can amend this to

  Note: there is a slight change in the NNN values assigned. The old
  code would increment the counter for every monitor added (except for
  -mon, -serial mon:..., -gdbstub), regardless of whether it needed a
  "compat_monitorNNN" ID assignment. Now it is only incremented when an
  automatic ID assigned is needed (but even for -mon, -serial mon:...,
  -gdbstub).

> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>