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

[Marcel Apfelbaum]

On 02/08/2016 01:02 PM, Laszlo Ersek wrote:
> On 02/08/16 11:46, Marcel Apfelbaum wrote:
> > 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.
>
> Please search this new function in your text editor for occurrences of
> "qemu_get_machine_opts", and you will see. :)

Ooops... I was thinking you wanted me to pass "opts" as parameter to 
set_machine_options.
Anyway, it wasn't for nothing, I saw that machine_opts is assigned twice, I'll 
send a patch shortly :)

Finally got it, thanks
Marcel


> Thanksargument
> Laszlo
>
> > > 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);