Re: [Qemu-devel] [PATCH V2] vl.c: fixed regression in machine error message

[Marcel Apfelbaum]

On 02/08/2016 12:28 PM, Laszlo Ersek wrote:
> On 02/08/16 11:09, Marcel Apfelbaum wrote:
> > Commit e1ce0c3cb(vl.c: fix regression when reading machine type from config 
> > file)
> > fixed the error message when the machine type was supplied inside the
> > config file. However now the option name is not displayed correctly if
> > the error happens when the machine is specified at command line.
> >
> > Running
> >      ./x86_64-softmmu/qemu-system-x86_64 -M q35-1.5 -redir tcp:8022::22
> > will result in the error message:
> >      qemu-system-x86_64: -redir tcp:8022::22: unsupported machine type
> >      Use -machine help to list supported machines
> >
> > Fixed it by saving the error location and also extracted the code
> > dealing with machine options into a separate function.
> >
> > v1 -> v2:
> >   - Addressed Laszlo Ersek's comments:
> >     - no need to save the machine options location, is saved in opts
> >     - rename the extracted method to set_machine_options
> >     - added the bug reporter to the CC
> >
> >   - tested with and without the config file and the error message is no OK:
>
> --> "is *now* OK". The typo ("no OK") should be please fixed up by the
> maintainer (unless another round is necessary).

Oh, v1->v2 section should be under -- line, I'll resend

> >   config file:
> >      - qemu-system-x86_64:machine-bug.conf:3: unsupported machine type
> >   cli:
> >     - qemu-system-x86_64: -M q35-1.5: unsupported machine type
> >
> > Reported-by: Michael S. Tsirkin <address@hidden>
> > Signed-off-by: Marcel Apfelbaum <address@hidden>
> > ---
> >   vl.c | 38 +++++++++++++++++++++++++++-----------
> >   1 file changed, 27 insertions(+), 11 deletions(-)
> >
> > diff --git a/vl.c b/vl.c
> > index f043009..dd29807 100644
> > --- a/vl.c
> > +++ b/vl.c
> > @@ -2751,6 +2751,32 @@ static const QEMUOption *lookup_opt(int argc, char 
> > **argv,
> >       return popt;
> >   }
> >
> > +static void set_machine_options(MachineClass **machine_class)
> > +{
> > +    const char *optarg;
> > +    QemuOpts *opts;
> > +    Location loc;
> > +
> > +    loc_push_none(&loc);
> > +
> > +    opts = qemu_get_machine_opts();
> > +    loc_push_none(&loc);
> > +    qemu_opts_loc_restore(opts);
> > +
> > +    optarg = qemu_opt_get(qemu_get_machine_opts(), "type");
>
> Not particularly important, but you could just pass "opts" as first arg
> here, rather than calling qemu_get_machine_opts() again. For style
> reasons, can you clean it up?

I would have nothing against it, but how can we be sure that opts poins to 
machine opts
at the time set_machine_options is called? Or I am missing something.

> With that:
>
> Reviewed-by: Laszlo Ersek <address@hidden>

Thanks! Waiting for your comment to the above and I'll post again.
Marcel

> Thanks
> Laszlo
>
> > +    if (optarg) {
> > +        *machine_class = machine_parse(optarg);
> > +    }
> > +
> > +    if (*machine_class == NULL) {
> > +        error_report("No machine specified, and there is no default");
> > +        error_printf("Use -machine help to list supported machines\n");
> > +        exit(1);
> > +    }
> > +
> > +    loc_pop(&loc);
> > +}
> > +
> >   static int machine_set_property(void *opaque,
> >                                   const char *name, const char *value,
> >                                   Error **errp)
> > @@ -4019,17 +4045,7 @@ int main(int argc, char **argv, char **envp)
> >
> >       replay_configure(icount_opts);
> >
> > -    opts = qemu_get_machine_opts();
> > -    optarg = qemu_opt_get(opts, "type");
> > -    if (optarg) {
> > -        machine_class = machine_parse(optarg);
> > -    }
> > -
> > -    if (machine_class == NULL) {
> > -        error_report("No machine specified, and there is no default");
> > -        error_printf("Use -machine help to list supported machines\n");
> > -        exit(1);
> > -    }
> > +    set_machine_options(&machine_class);
> >
> >       set_memory_options(&ram_slots, &maxram_size, machine_class);