Re: [Qemu-devel] [PATCH v2 1/5] acpi, pc: Add hotunplug request cb for pc machine.

[Michael S. Tsirkin]

On Wed, Jan 28, 2015 at 04:33:02PM +0800, Zhu Guihua wrote:
> On Wed, 2015-01-28 at 10:02 +0200, Michael S. Tsirkin wrote:
> > On Wed, Jan 28, 2015 at 03:45:37PM +0800, Zhu Guihua wrote:
> > > From: Tang Chen <address@hidden>
> > > 
> > > Memory and CPU hot unplug are both asynchronous procedures.
> > > They both need unplug request callback to initiate unplug operation.
> > > 
> > > Add unplug handler to pc machine that will be used by following
> > > CPU and memory unplug patches.
> > > 
> > > Reviewed-by: Igor Mammedov <address@hidden>
> > > Signed-off-by: Tang Chen <address@hidden>
> > > Signed-off-by: Zhu Guihua <address@hidden>
> > > ---
> > >  hw/i386/pc.c | 8 ++++++++
> > >  1 file changed, 8 insertions(+)
> > > 
> > > diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> > > index c7af6aa..15ee10a 100644
> > > --- a/hw/i386/pc.c
> > > +++ b/hw/i386/pc.c
> > > @@ -1680,6 +1680,13 @@ static void 
> > > pc_machine_device_plug_cb(HotplugHandler *hotplug_dev,
> > >      }
> > >  }
> > >  
> > > +static void pc_machine_device_unplug_request_cb(HotplugHandler 
> > > *hotplug_dev,
> > > +                                                DeviceState *dev, Error 
> > > **errp)
> > > +{
> > > +    error_setg(errp, "acpi: device unplug request for not supported 
> > > device"
> > > +               " type: %s", object_get_typename(OBJECT(dev)));
> > > +}
> > > +
> > >  static HotplugHandler *pc_get_hotpug_handler(MachineState *machine,
> > >                                               DeviceState *dev)
> > >  {
> > 
> > 
> > So this is just a stub, your follow-up patches replace it with
> > something more useful?
> > 
> > Why do we need the stub stage though?
> > Why not just add whatever's going to be there eventually?
> > 
> 
> This function will be used in memory hot-unplug
> [RESEND PATCH v1 07/13] pc-dimm: Add memory hot unplug request support
> for pc-dimm.
> https://lists.nongnu.org/archive/html/qemu-devel/2015-01/msg00592.html
> 
> and cpu hot-unplug
> [PATCH v2 05/11] pc: add cpu hot unplug request callback support
> https://lists.nongnu.org/archive/html/qemu-devel/2015-01/msg01562.html
> 
> Regards,
> Zhu

OK, so the point is to make it easier to resolve conflicts between the two 
series?

> > 
> > > @@ -1809,6 +1816,7 @@ static void pc_machine_class_init(ObjectClass *oc, 
> > > void *data)
> > >      pcmc->get_hotplug_handler = mc->get_hotplug_handler;
> > >      mc->get_hotplug_handler = pc_get_hotpug_handler;
> > >      hc->plug = pc_machine_device_plug_cb;
> > > +    hc->unplug_request = pc_machine_device_unplug_request_cb;
> > >  }
> > >  
> > >  static const TypeInfo pc_machine_info = {
> > > -- 
> > > 1.9.3
>