Re: [Qemu-devel] [PATCH v3 4/7] qmp: enable query-[chardev|version|name|uuid|iothreads|memdev] commands in preconfig state

[Markus Armbruster <armbru@redhat.com>]

"Dr. David Alan Gilbert" <dgilbert@redhat.com> writes:

> * Markus Armbruster (armbru@redhat.com) wrote:
>> "Dr. David Alan Gilbert (git)" <dgilbert@redhat.com> writes:
>> 
>> > From: Igor Mammedov <imammedo@redhat.com>
>> >
>> > subj commands, are informational and do not depend on machine being
>> > initialized. Make them available early in preconfig runstate to make
>> > the later a little bit more useful.
>> >
>> > Signed-off-by: Igor Mammedov <imammedo@redhat.com>
>> 
>> Excessively long subject line.  Suggested fix:
>> 
>>     qmp: Enable a few query- commands in preconfig state
>> 
>>     Commands query-chardev, query-version, query-name, query-uuid,
>>     query-iothreads, query-memdev are informational and do not depend on
>>     the machine being initialized.  Make them available in preconfig
>>     runstate to make the latter a little bit more useful.
>> 
>> > ---
>> >  qapi/char.json |  3 ++-
>> >  qapi/misc.json | 12 +++++++-----
>> >  2 files changed, 9 insertions(+), 6 deletions(-)
>> >
>> > diff --git a/qapi/char.json b/qapi/char.json
>> > index ae19dcd1ed..60f31d83fc 100644
>> > --- a/qapi/char.json
>> > +++ b/qapi/char.json
>> > @@ -62,7 +62,8 @@
>> >  #    }
>> >  #
>> >  ##
>> > -{ 'command': 'query-chardev', 'returns': ['ChardevInfo'] }
>> > +{ 'command': 'query-chardev', 'returns': ['ChardevInfo'],
>> > +  'allow-preconfig': true }
>> 
>> Okay because
>> 
>>     if (qemu_opts_foreach(qemu_find_opts("chardev"),
>>                           chardev_init_func, NULL, NULL)) {
>>         exit(1);
>>     }
>> 
>> runs before -preconfig's main_loop().
>> 
>> >  
>> >  ##
>> >  # @ChardevBackendInfo:
>> > diff --git a/qapi/misc.json b/qapi/misc.json
>> > index f83a63a0ab..1be1728c0e 100644
>> > --- a/qapi/misc.json
>> > +++ b/qapi/misc.json
>> > @@ -117,7 +117,8 @@
>> >  #    }
>> >  #
>> >  ##
>> > -{ 'command': 'query-version', 'returns': 'VersionInfo' }
>> > +{ 'command': 'query-version', 'returns': 'VersionInfo',
>> > +  'allow-preconfig': true }
>> 
>> Returns data fixed at compile time.  Okay.
>> 
>> >  
>> >  ##
>> >  # @CommandInfo:
>> > @@ -241,7 +242,7 @@
>> >  # <- { "return": { "name": "qemu-name" } }
>> >  #
>> >  ##
>> > -{ 'command': 'query-name', 'returns': 'NameInfo' }
>> > +{ 'command': 'query-name', 'returns': 'NameInfo', 'allow-preconfig': true }
>> 
>> Okay because parse_name() runs before -preconfig's main_loop().
>> 
>> >  ##
>> >  # @KvmInfo:
>> > @@ -301,7 +302,7 @@
>> >  # <- { "return": { "UUID": "550e8400-e29b-41d4-a716-446655440000" } }
>> >  #
>> >  ##
>> > -{ 'command': 'query-uuid', 'returns': 'UuidInfo' }
>> > +{ 'command': 'query-uuid', 'returns': 'UuidInfo', 'allow-preconfig': true }
>> 
>> Okay because qemu_uuid(optarg, &qemu_uuid) runs before -preconfig's
>> main_loop().
>> 
>> >  
>> >  ##
>> >  # @EventInfo:
>> > @@ -710,7 +711,8 @@
>> >  #    }
>> >  #
>> >  ##
>> > -{ 'command': 'query-iothreads', 'returns': ['IOThreadInfo'] }
>> > +{ 'command': 'query-iothreads', 'returns': ['IOThreadInfo'],
>> > +  'allow-preconfig': true }
>> 
>> Feeling lazy... why is this one okay?
>
> Because it's a walk of the entire object tree; with
> object_get_objects_root() - assuming the object tree exists we're safe.
>
>> >  
>> >  ##
>> >  # @BalloonInfo:
>> > @@ -2902,7 +2904,7 @@
>> >  #    }
>> >  #
>> >  ##
>> > -{ 'command': 'query-memdev', 'returns': ['Memdev'] }
>> > +{ 'command': 'query-memdev', 'returns': ['Memdev'], 'allow-preconfig': true }
>> >  
>> >  ##
>> >  # @PCDIMMDeviceInfo:
>> 
>> And this one?
>
> Same trick as query-iothreads.

Thanks.