Re: [Qemu-devel] [qemu-s390x] [PATCH v1 1/8] pc: local error handling in hotplug handler functions

[Thomas Huth <thuth@redhat.com>]

On 07.06.2018 18:52, David Hildenbrand wrote:
> Let's introduce and use local error variables in the hotplug handler
> functions.

Why? You don't check local_err in the functions, so I fail to see why
this is needed? If you need this in a later patch, I think this should
simply be part of that later patch instead.

 Thomas


> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  hw/i386/pc.c | 32 ++++++++++++++++++++++----------
>  1 file changed, 22 insertions(+), 10 deletions(-)
> 
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index f3befe6721..8075c6af15 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -2006,45 +2006,57 @@ static void pc_cpu_pre_plug(HotplugHandler *hotplug_dev,
>  static void pc_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
>                                            DeviceState *dev, Error **errp)
>  {
> +    Error *local_err = NULL;
> +
>      if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
> -        pc_cpu_pre_plug(hotplug_dev, dev, errp);
> +        pc_cpu_pre_plug(hotplug_dev, dev, &local_err);
>      }
> +    error_propagate(errp, local_err);
>  }
>  
>  static void pc_machine_device_plug_cb(HotplugHandler *hotplug_dev,
>                                        DeviceState *dev, Error **errp)
>  {
> +    Error *local_err = NULL;
> +
>      if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> -        pc_dimm_plug(hotplug_dev, dev, errp);
> +        pc_dimm_plug(hotplug_dev, dev, &local_err);
>      } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
> -        pc_cpu_plug(hotplug_dev, dev, errp);
> +        pc_cpu_plug(hotplug_dev, dev, &local_err);
>      }
> +    error_propagate(errp, local_err);
>  }
>  
>  static void pc_machine_device_unplug_request_cb(HotplugHandler *hotplug_dev,
>                                                  DeviceState *dev, Error **errp)
>  {
> +    Error *local_err = NULL;
> +
>      if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> -        pc_dimm_unplug_request(hotplug_dev, dev, errp);
> +        pc_dimm_unplug_request(hotplug_dev, dev, &local_err);
>      } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
> -        pc_cpu_unplug_request_cb(hotplug_dev, dev, errp);
> +        pc_cpu_unplug_request_cb(hotplug_dev, dev, &local_err);
>      } else {
> -        error_setg(errp, "acpi: device unplug request for not supported device"
> -                   " type: %s", object_get_typename(OBJECT(dev)));
> +        error_setg(&local_err, "acpi: device unplug request for not supported"
> +                   " device type: %s", object_get_typename(OBJECT(dev)));
>      }
> +    error_propagate(errp, local_err);
>  }
>  
>  static void pc_machine_device_unplug_cb(HotplugHandler *hotplug_dev,
>                                          DeviceState *dev, Error **errp)
>  {
> +    Error *local_err = NULL;
> +
>      if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> -        pc_dimm_unplug(hotplug_dev, dev, errp);
> +        pc_dimm_unplug(hotplug_dev, dev, &local_err);
>      } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
> -        pc_cpu_unplug_cb(hotplug_dev, dev, errp);
> +        pc_cpu_unplug_cb(hotplug_dev, dev, &local_err);
>      } else {
> -        error_setg(errp, "acpi: device unplug for not supported device"
> +        error_setg(&local_err, "acpi: device unplug for not supported device"
>                     " type: %s", object_get_typename(OBJECT(dev)));
>      }
> +    error_propagate(errp, local_err);
>  }
>  
>  static HotplugHandler *pc_get_hotpug_handler(MachineState *machine,
>