Re: [Qemu-devel] [Bug 1462131] Re: qemu mainline regression with xen-unstable: unable to start QMP

[Paolo Bonzini <pbonzini@redhat.com>]

On 05/06/2015 00:15, Don Slutz wrote:
> QMP also uses id, but apparently removes it up front before calling into
> this function; so another fix would be having xen remove it up front.

No, we don't break users.

This patch fixes Xen but not virt-test, which relies on ids.  It greps
the QMP output for an ID in order to find the output of query-commands.

Paolo

>> > 
>> > Signed-off-by: Don Slutz <dslutz@verizon.com>
>> > ---
>> >  monitor.c | 9 +++++++++
>> >  1 file changed, 9 insertions(+)
>> > 
>> > diff --git a/monitor.c b/monitor.c
>> > index c7baa91..e9a0747 100644
>> > --- a/monitor.c
>> > +++ b/monitor.c
>> > @@ -4955,6 +4955,15 @@ static QDict *qmp_check_input_obj(QObject
>> > *input_obj, Error **errp)
>> >                            "arguments", "object");
>> >                  return NULL;
>> >              }
>> > +        } else if (!strcmp(arg_name, "id")) {
>> > +            /*
>> > +             * Fixup Xen's usage. Just ignore the "id". See point #5
>> > +             * above.  This was an attempt at an asynchronous
>> > +             * command interface.  However commit
>> > +             * 65207c59d99f2260c5f1d3b9c491146616a522aa is
>> > +             * wrong. Xen does not expect an error when it passes in
>> > +             * "id":1, so just continue to ignore it.
>> > +             */
> The comment is a bit verbose, particularly since 'id' is a
> well-established usage pattern in QMP.  Also, we don't need to call out
> why it changed in the comment here, the commit message is sufficient for
> that.
>