Re: [Qemu-devel] [PATCH 4/5] pc: add cpu hotplug handler to PC_MACHINE

[Igor Mammedov <imammedo@redhat.com>]

On Wed,  3 Sep 2014 17:06:16 +0800
Gu Zheng <guz.fnst@cn.fujitsu.com> wrote:

> Add cpu hotplug handler to PC_MACHINE, which will perform the acpi
> cpu hotplug callback via hotplug_handler API.
> 
> Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
> ---
>  hw/i386/pc.c |   26 +++++++++++++++++++++++++-
>  qom/cpu.c    |    1 -
>  2 files changed, 25 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 8fa8d2f..c2956f9 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -1607,11 +1607,34 @@ out:
>      error_propagate(errp, local_err);
>  }
>  
> +static void pc_cpu_plug(HotplugHandler *hotplug_dev,
> +                         DeviceState *dev, Error **errp)
> +{
> +    HotplugHandlerClass *hhc;
> +    Error *local_err = NULL;
> +    PCMachineState *pcms = PC_MACHINE(hotplug_dev);
> +
> +    if (dev->hotplugged) {
for startup CPUs we set gpe_cpu status bits in AcpiCpuHotplug_init()
and for hotpluged in AcpiCpuHotplug_add() which is duplicating
essentially the same code.

Could you drop above check and make AcpiCpuHotplug_init() take care
about startup CPUs as well, keeping bit setting in one place.

> +        if (!pcms->acpi_dev) {
> +            error_setg(&local_err,
> +                   "cpu hotplug is not enabled: missing acpi device");
> +            goto out;
> +        }
> +
> +        hhc = HOTPLUG_HANDLER_GET_CLASS(pcms->acpi_dev);
> +        hhc->plug(HOTPLUG_HANDLER(pcms->acpi_dev), dev, &local_err);
> +out:
> +        error_propagate(errp, local_err);
> +    }
> +}
> +
>  static void pc_machine_device_plug_cb(HotplugHandler *hotplug_dev,
>                                        DeviceState *dev, Error **errp)
>  {
>      if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
>          pc_dimm_plug(hotplug_dev, dev, errp);
> +    } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
> +        pc_cpu_plug(hotplug_dev, dev, errp);
>      }
>  }
>  
> @@ -1620,7 +1643,8 @@ static HotplugHandler *pc_get_hotpug_handler(MachineState *machine,
>  {
>      PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(machine);
>  
> -    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> +    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)
> +        || object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
>          return HOTPLUG_HANDLER(machine);
>      }
>  
> diff --git a/qom/cpu.c b/qom/cpu.c
> index b32dd0a..af8e83f 100644
> --- a/qom/cpu.c
> +++ b/qom/cpu.c
> @@ -304,7 +304,6 @@ static void cpu_common_realizefn(DeviceState *dev, Error **errp)
>      if (dev->hotplugged) {
>          cpu_synchronize_post_init(cpu);
>          notifier_list_notify(&cpu_added_notifiers, dev);
> -        cpu_resume(cpu);
>      }
>  }
>  

I don't see what sets PCMachine as hotplug_handler for CPU,
maybe series is missing a patch?