Re: [Qemu-devel] [RFC v5 07/26] monitor: unify global init

[Peter Xu]

On Wed, Dec 13, 2017 at 03:48:06PM +0000, Stefan Hajnoczi wrote:
> On Tue, Dec 05, 2017 at 01:51:41PM +0800, Peter Xu wrote:
> > diff --git a/vl.c b/vl.c
> > index 1ad1c04637..1ec995a6ae 100644
> > --- a/vl.c
> > +++ b/vl.c
> > @@ -3144,7 +3144,6 @@ int main(int argc, char **argv, char **envp)
> >      qemu_init_exec_dir(argv[0]);
> >  
> >      module_call_init(MODULE_INIT_QOM);
> > -    monitor_init_qmp_commands();
> >  
> >      qemu_add_opts(&qemu_drive_opts);
> >      qemu_add_drive_opts(&qemu_legacy_drive_opts);
> > @@ -4690,6 +4689,8 @@ int main(int argc, char **argv, char **envp)
> >      default_drive(default_floppy, snapshot, IF_FLOPPY, 0, FD_OPTS);
> >      default_drive(default_sdcard, snapshot, IF_SD, 0, SD_OPTS);
> >  
> > +    monitor_init_globals();
> 
> Why did you move monitor_init_qmp_commands() down here?
> 
> There are many function calls between the old position and the new
> position.  Did you check all of them to make sure they don't touch the
> monitor which is now totally uninitialized?

Yeh, this patch is a bit hairy, but I really think we should do it.
Because there are too many places (as you have seen) that we inited
monitor stuff in different places.

IMHO monitor_init_qmp_commands() should be safe to be called here
since it only do registration of commands, and AFAICT those commands
won't be touched until we init any of the monitors below
monitor_init_globals():

    if (qemu_opts_foreach(qemu_find_opts("mon"),
                          mon_init_func, NULL, NULL)) {
        exit(1);
    }

Similar things to other stuff in monitor_init_globals().  They just
won't be touched up (correct me if not) until this mon_init_func().

Thanks,

-- 
Peter Xu