Re: [Qemu-devel] [PATCH 1/3] qdev: Create qdev_get_device_class() function

[Andreas Färber]

Hi,

Am 01.11.2014 um 16:56 schrieb Eduardo Habkost:
> Extract the DeviceClass lookup from qdev_device_add() to a separate
> function.
> 
> Signed-off-by: Eduardo Habkost <address@hidden>
> ---
>  qdev-monitor.c | 70 
> +++++++++++++++++++++++++++++++++++-----------------------
>  1 file changed, 42 insertions(+), 28 deletions(-)
> 
> diff --git a/qdev-monitor.c b/qdev-monitor.c
> index fac7d17..982f3f4 100644
> --- a/qdev-monitor.c
> +++ b/qdev-monitor.c
> @@ -180,6 +180,44 @@ static const char *find_typename_by_alias(const char 
> *alias)
>      return NULL;
>  }
>  
> +static DeviceClass *qdev_get_device_class(const char **driver, Error **errp)

Since this does nothing qdev-specific, what about
device_get_class_by_name()? The only that's not generically suitable for
hw/core/ is the "driver" naming in the error handling; otherwise it
looks very similar to the CPUClass hooks I added a while back.

> +{
> +    ObjectClass *oc;
> +    DeviceClass *dc;
> +
> +    oc = object_class_by_name(*driver);
> +    if (!oc) {
> +        const char *typename = find_typename_by_alias(*driver);
> +
> +        if (typename) {
> +            *driver = typename;
> +            oc = object_class_by_name(*driver);
> +        }
> +    }
> +
> +    if (!object_class_dynamic_cast(oc, TYPE_DEVICE)) {
> +        error_setg(errp, "'%s' is not a valid device model name", *driver);
> +        return NULL;
> +    }
> +
> +    if (object_class_is_abstract(oc)) {
> +        error_set(errp, QERR_INVALID_PARAMETER_VALUE, "driver",
> +                  "non-abstract device type");
> +        return NULL;
> +    }
> +

See 3/3 for whether we may want to return here.

> +    dc = DEVICE_CLASS(oc);
> +    if (dc->cannot_instantiate_with_device_add_yet ||
> +        (qdev_hotplug && !dc->hotpluggable)) {
> +        error_set(errp, QERR_INVALID_PARAMETER_VALUE, "driver",
> +                  "pluggable device type");
> +        return NULL;
> +    }
> +
> +    return dc;
> +}
> +
> +
>  int qdev_device_help(QemuOpts *opts)
>  {
>      Error *local_err = NULL;
> @@ -455,7 +493,6 @@ static BusState *qbus_find(const char *path)
>  
>  DeviceState *qdev_device_add(QemuOpts *opts)
>  {
> -    ObjectClass *oc;
>      DeviceClass *dc;
>      const char *driver, *path, *id;
>      DeviceState *dev;
> @@ -469,33 +506,10 @@ DeviceState *qdev_device_add(QemuOpts *opts)
>      }
>  
>      /* find driver */
> -    oc = object_class_by_name(driver);
> -    if (!oc) {
> -        const char *typename = find_typename_by_alias(driver);
> -
> -        if (typename) {
> -            driver = typename;
> -            oc = object_class_by_name(driver);
> -        }
> -    }
> -
> -    if (!object_class_dynamic_cast(oc, TYPE_DEVICE)) {
> -        qerror_report(ERROR_CLASS_GENERIC_ERROR,
> -                      "'%s' is not a valid device model name", driver);
> -        return NULL;
> -    }
> -
> -    if (object_class_is_abstract(oc)) {
> -        qerror_report(QERR_INVALID_PARAMETER_VALUE, "driver",
> -                      "non-abstract device type");
> -        return NULL;
> -    }
> -
> -    dc = DEVICE_CLASS(oc);
> -    if (dc->cannot_instantiate_with_device_add_yet ||
> -        (qdev_hotplug && !dc->hotpluggable)) {
> -        qerror_report(QERR_INVALID_PARAMETER_VALUE, "driver",
> -                      "pluggable device type");
> +    dc = qdev_get_device_class(&driver, &err);
> +    if (err) {
> +        qerror_report_err(err);
> +        error_free(err);
>          return NULL;
>      }
>  

Otherwise looks good.

Regards,
Andreas

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