Re: [Qemu-devel] [PATCH 5/4] vl: Clean up machine selection in main().

[Marcel Apfelbaum <marcel@redhat.com>]

On 02/16/2016 04:57 PM, Markus Armbruster wrote:
> We set machine_class to the default first, and update it to the real
> one later.  Any use of machine_class in between is almost certainly
> wrong.  Set it once and for all instead.
>
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>   vl.c | 11 ++++++-----
>   1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/vl.c b/vl.c
> index 7918e9f..098728c 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -2748,8 +2748,9 @@ static const QEMUOption *lookup_opt(int argc, char **argv,
>       return popt;
>   }
>
> -static void set_machine_options(MachineClass **machine_class)
> +static MachineClass *select_machine(MachineClass *dflt)

Hi Markus,

I am no fan of "dflt" naming, but I can live with it.

>   {
> +    MachineClass *machine_class = dflt;
>       const char *optarg;
>       QemuOpts *opts;
>       Location loc;
> @@ -2761,16 +2762,17 @@ static void set_machine_options(MachineClass **machine_class)
>
>       optarg = qemu_opt_get(opts, "type");
>       if (optarg) {
> -        *machine_class = machine_parse(optarg);
> +        machine_class = machine_parse(optarg);
>       }
>
> -    if (*machine_class == NULL) {
> +    if (!machine_class) {
>           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);
> +    return machine_class;
>   }
>
>   static int machine_set_property(void *opaque,
> @@ -3075,7 +3077,6 @@ int main(int argc, char **argv, char **envp)
>       os_setup_early_signal_handling();
>
>       module_call_init(MODULE_INIT_MACHINE);
> -    machine_class = find_default_machine();
>       cpu_model = NULL;
>       snapshot = 0;
>       cyls = heads = secs = 0;
> @@ -4066,7 +4067,7 @@ int main(int argc, char **argv, char **envp)
>
>       replay_configure(icount_opts);
>
> -    set_machine_options(&machine_class);
> +    machine_class = select_machine(find_default_machine());

I like the approach "going all the way", I would
even hide the call to find_default_machine inside select_machine.

Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>


Thanks,
Marcel

>
>       set_memory_options(&ram_slots, &maxram_size, machine_class);
>
>