Re: [Qemu-devel] [RESEND PATCH v4 5/6] pc-dimm: Add memory hot unplug support for pc-dimm

[Igor Mammedov <imammedo@redhat.com>]

On Mon, 16 Mar 2015 16:58:17 +0800
Zhu Guihua <zhugh.fnst@cn.fujitsu.com> wrote:

> From: Tang Chen <tangchen@cn.fujitsu.com>
> 
> Implement unplug cb for pc-dimm. It calls memory unplug cb to reset
> some memory status, removes the corresponding memory region, and
> unregisters vmstate.
> 
> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
> Signed-off-by: Zhu Guihua <zhugh.fnst@cn.fujitsu.com>
Please, squash this patch into previous.

> ---
>  hw/i386/pc.c | 26 ++++++++++++++++++++++++--
>  1 file changed, 24 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 9c7c318..141fa6a 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -1689,6 +1689,23 @@ out:
>      error_propagate(errp, local_err);
>  }
>  
> +static void pc_dimm_unplug(HotplugHandler *hotplug_dev,
> +                           DeviceState *dev, Error **errp)
> +{
> +    PCMachineState *pcms = PC_MACHINE(hotplug_dev);
> +    PCDIMMDevice *dimm = PC_DIMM(dev);
> +    PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
> +    MemoryRegion *mr = ddc->get_memory_region(dimm);
> +    HotplugHandlerClass *hhc;
> +    Error *local_err = NULL;
> +
> +    hhc = HOTPLUG_HANDLER_GET_CLASS(pcms->acpi_dev);
> +    hhc->unplug(HOTPLUG_HANDLER(pcms->acpi_dev), dev, &local_err);
potentially leaking local_err, should be propagated to errp
and maybe in case of error here we shouldn't proceed with removal.


> +
> +    memory_region_del_subregion(&pcms->hotplug_memory, mr);
> +    vmstate_unregister_ram(mr, dev);
> +}
> +
>  static void pc_cpu_plug(HotplugHandler *hotplug_dev,
>                          DeviceState *dev, Error **errp)
>  {
> @@ -1742,8 +1759,13 @@ static void pc_machine_device_unplug_request_cb(HotplugHandler *hotplug_dev,
>  static void pc_machine_device_unplug_cb(HotplugHandler *hotplug_dev,
>                                          DeviceState *dev, Error **errp)
>  {
> -    error_setg(errp, "acpi: device unplug for not supported device"
> -               " type: %s", object_get_typename(OBJECT(dev)));
> +    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> +        pc_dimm_unplug(hotplug_dev, dev, errp);
> +        object_unparent(OBJECT(dev));
Pls, do unparenting in pc_dimm_unplug()

> +    } else {
> +        error_setg(errp, "acpi: device unplug for not supported device"
> +                   " type: %s", object_get_typename(OBJECT(dev)));
> +    }
>  }
>  
>  static HotplugHandler *pc_get_hotpug_handler(MachineState *machine,