Re: [PATCH v2 10/18] qom: introduce object_register_sugar_prop

[Marc-André Lureau]

Hi

On Mon, Dec 9, 2019 at 7:10 PM Paolo Bonzini <address@hidden> wrote:
>
> Similar to the existing "-rtc driftfix" option, we will convert some
> legacy "-machine" command line options to global properties on accelerators.
> Because accelerators are not devices, we cannot use qdev_prop_register_global.
> Instead, provide a slot in the generic object_compat_props arrays for
> command line syntactic sugar.
>
> Signed-off-by: Paolo Bonzini <address@hidden>
> ---
>  include/qom/object.h |  1 +
>  qom/object.c         | 23 +++++++++++++++++++++--
>  vl.c                 | 10 +++-------
>  3 files changed, 25 insertions(+), 9 deletions(-)
>
> diff --git a/include/qom/object.h b/include/qom/object.h
> index 128d00c..230b18f 100644
> --- a/include/qom/object.h
> +++ b/include/qom/object.h
> @@ -679,6 +679,7 @@ void object_apply_global_props(Object *obj, const 
> GPtrArray *props,
>                                 Error **errp);
>  void object_set_machine_compat_props(GPtrArray *compat_props);
>  void object_set_accelerator_compat_props(GPtrArray *compat_props);
> +void object_register_sugar_prop(const char *driver, const char *prop, const 
> char *value);
>  void object_apply_compat_props(Object *obj);
>
>  /**
> diff --git a/qom/object.c b/qom/object.c
> index d51b57f..bfb4413 100644
> --- a/qom/object.c
> +++ b/qom/object.c
> @@ -414,10 +414,29 @@ void object_apply_global_props(Object *obj, const 
> GPtrArray *props, Error **errp
>   * Global property defaults
>   * Slot 0: accelerator's global property defaults
>   * Slot 1: machine's global property defaults
> + * Slot 2: global properties from legacy command line option
>   * Each is a GPtrArray of of GlobalProperty.
>   * Applied in order, later entries override earlier ones.
>   */
> -static GPtrArray *object_compat_props[2];
> +static GPtrArray *object_compat_props[3];
> +
> +/*
> + * Retrieve @GPtrArray for global property defined with options
> + * other than "-global".  These are generally used for syntactic
> + * sugar and legacy command line options.
> + */
> +void object_register_sugar_prop(const char *driver, const char *prop, const 
> char *value)
> +{
> +    GlobalProperty *g;
> +    if (!object_compat_props[2]) {
> +        object_compat_props[2] = g_ptr_array_new();
> +    }
> +    g = g_new(GlobalProperty, 1);
> +    g->driver = g_strdup(driver);
> +    g->property = g_strdup(prop);
> +    g->value = g_strdup(value);
> +    g_ptr_array_add(object_compat_props[2], g);
> +}
>
>  /*
>   * Set machine's global property defaults to @compat_props.
> @@ -445,7 +464,7 @@ void object_apply_compat_props(Object *obj)
>
>      for (i = 0; i < ARRAY_SIZE(object_compat_props); i++) {
>          object_apply_global_props(obj, object_compat_props[i],
> -                                  &error_abort);
> +                                  i == 2 ? &error_fatal : &error_abort);
>      }
>  }
>
> diff --git a/vl.c b/vl.c
> index 58aad4f..d6c77bc 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -897,13 +897,9 @@ static void configure_rtc(QemuOpts *opts)
>      value = qemu_opt_get(opts, "driftfix");
>      if (value) {
>          if (!strcmp(value, "slew")) {
> -            static GlobalProperty slew_lost_ticks = {
> -                .driver   = "mc146818rtc",
> -                .property = "lost_tick_policy",
> -                .value    = "slew",
> -            };
> -
> -            qdev_prop_register_global(&slew_lost_ticks);
> +            object_register_sugar_prop("mc146818rtc",
> +                                       "lost_tick_policy",
> +                                       "slew");
>          } else if (!strcmp(value, "none")) {
>              /* discard is default */
>          } else {
> --
> 1.8.3.1
>
>
>


I am not too happy about the change, but the "global properties"
handling is an area that can be improved later.

Reviewed-by: Marc-André Lureau <address@hidden>


-- 
Marc-André Lureau