Re: [Qemu-devel] [PATCHv8 2/3] fw_cfg: move qdev_init_nofail() from fw_cfg_init1() to callers

[Eduardo Habkost <ehabkost@redhat.com>]

On Tue, Jul 11, 2017 at 09:02:12PM +0100, Mark Cave-Ayland wrote:
> When looking to instantiate a TYPE_FW_CFG_MEM or TYPE_FW_CFG_IO device to be
> able to wire it up differently, it is much more convenient for the caller to
> instantiate the device and have the fw_cfg default files already preloaded
> during realize.
> 
> Move fw_cfg_init1() to the end of both the fw_cfg_mem_realize() and
> fw_cfg_io_realize() functions so it no longer needs to be called manually
> when instantiating the device, and also rename it to fw_cfg_common_realize()
> which better describes its new purpose.
> 
> Since it is now the responsibility of the machine to wire up the fw_cfg device
> it is necessary to introduce a object_property_add_child() call into
> fw_cfg_init_io() and fw_cfg_init_mem() to link the fw_cfg device to the root
> machine object as before.
> 
> Finally with the previous change to fw_cfg_find() we can now remove the
> assert() preventing multiple fw_cfg devices being instantiated and replace
> them with a simple call to fw_cfg_find() at realize time instead. This allows
> us to remove FW_CFG_NAME and FW_CFG_PATH since they are no longer required.
> 
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> Reviewed-by: Igor Mammedov <imammedo@redhat.com>
[...]
> @@ -1096,6 +1097,12 @@ static void fw_cfg_io_realize(DeviceState *dev, Error **errp)
>                                &fw_cfg_dma_mem_ops, FW_CFG(s), "fwcfg.dma",
>                                sizeof(dma_addr_t));
>      }
> +
> +    fw_cfg_common_realize(dev, &local_err);
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +        return;
> +    }
>  }

"if (local_err)" is redundant, as error_propagate() does nothing
if local_err is NULL.  "return" is also unnecessary here.  You
also don't need local_err/error_propagate() if you are not
looking at the value of local_err at all.  This means those 5
lines can be simply written as:

    fw_cfg_common_realize(dev, errp);

(Sorry for not noticing that in v7)

>  
>  static void fw_cfg_io_class_init(ObjectClass *klass, void *data)
> @@ -1162,6 +1169,12 @@ static void fw_cfg_mem_realize(DeviceState *dev, Error **errp)
>                                sizeof(dma_addr_t));
>          sysbus_init_mmio(sbd, &FW_CFG(s)->dma_iomem);
>      }
> +
> +    fw_cfg_common_realize(dev, &local_err);
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +        return;
> +    }

Same as above.


>  }
>  
>  static void fw_cfg_mem_class_init(ObjectClass *klass, void *data)
> -- 
> 1.7.10.4
> 

-- 
Eduardo