By default MachineClass::get_hotplug_handler is NULL and concrete board
should set it to it's own handler.
Considering there isn't any default handler, drop saving empty
MachineClass::get_hotplug_handler in child class and make PC code
consistent with spapr/s390x boards.

We can bring this back when actual usecase surfaces and do it
consistently across boards that use get_hotplug_handler().

Suggested-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
CC: mst@redhat.com
CC: ehabkost@redhat.com
---
 include/hw/i386/pc.h | 8 --------
 hw/i386/pc.c         | 6 +-----
 2 files changed, 1 insertion(+), 13 deletions(-)

diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index ffee841..fac6689 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -84,10 +84,6 @@ struct PCMachineState {
 /**
  * PCMachineClass:
  *
- * Methods:
- *
- * @get_hotplug_handler: pointer to parent class callback @get_hotplug_handler
- *
  * Compat fields:
  *
  * @enforce_aligned_dimm: check that DIMM's address/size is aligned by
@@ -107,10 +103,6 @@ struct PCMachineClass {
 
     /*< public >*/
 
-    /* Methods: */
-    HotplugHandler *(*get_hotplug_handler)(MachineState *machine,
-                                           DeviceState *dev);
-
     /* Device configuration: */
     bool pci_enabled;
     bool kvmclock_enabled;
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index d36bac8..bc144d2 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -2056,15 +2056,12 @@ static void pc_machine_device_unplug_cb(HotplugHandler *hotplug_dev,
 static HotplugHandler *pc_get_hotpug_handler(MachineState *machine,
                                              DeviceState *dev)
 {
-    PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(machine);
-
     if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM) ||
         object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
         return HOTPLUG_HANDLER(machine);
     }
 
-    return pcmc->get_hotplug_handler ?
-        pcmc->get_hotplug_handler(machine, dev) : NULL;
+    return NULL;
 }
 
 static void
@@ -2344,7 +2341,6 @@ static void pc_machine_class_init(ObjectClass *oc, void *data)
     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(oc);
     NMIClass *nc = NMI_CLASS(oc);
 
-    pcmc->get_hotplug_handler = mc->get_hotplug_handler;
     pcmc->pci_enabled = true;
     pcmc->has_acpi_build = true;
     pcmc->rsdp_in_ram = true;
-- 
2.7.4

On Wed, Apr 18, 2018 at 04:28:03PM +0200, Igor Mammedov wrote:
> By default MachineClass::get_hotplug_handler is NULL and concrete board
> should set it to it's own handler.
> Considering there isn't any default handler, drop saving empty
> MachineClass::get_hotplug_handler in child class and make PC code
> consistent with spapr/s390x boards.
> 
> We can bring this back when actual usecase surfaces and do it
> consistently across boards that use get_hotplug_handler().
> 
> Suggested-by: David Gibson <david@gibson.dropbear.id.au>
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>

Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>


[...]
> @@ -2344,7 +2341,6 @@ static void pc_machine_class_init(ObjectClass *oc, void *data)
>      HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(oc);
>      NMIClass *nc = NMI_CLASS(oc);
>  
> -    pcmc->get_hotplug_handler = mc->get_hotplug_handler;

What about assert(!mc->get_hotplug_handler) just before
overwriting it?

-- 
Eduardo

On 04/18/2018 11:56 AM, Eduardo Habkost wrote:
> On Wed, Apr 18, 2018 at 04:28:03PM +0200, Igor Mammedov wrote:
>> By default MachineClass::get_hotplug_handler is NULL and concrete board
>> should set it to it's own handler.
>> Considering there isn't any default handler, drop saving empty
>> MachineClass::get_hotplug_handler in child class and make PC code
>> consistent with spapr/s390x boards.
>>
>> We can bring this back when actual usecase surfaces and do it
>> consistently across boards that use get_hotplug_handler().
>>
>> Suggested-by: David Gibson <david@gibson.dropbear.id.au>
>> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> 
> Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
> 
> 
> [...]
>> @@ -2344,7 +2341,6 @@ static void pc_machine_class_init(ObjectClass *oc, void *data)
>>      HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(oc);
>>      NMIClass *nc = NMI_CLASS(oc);
>>  
>> -    pcmc->get_hotplug_handler = mc->get_hotplug_handler;
> 
> What about assert(!mc->get_hotplug_handler) just before
> overwriting it?

Good idea.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

On Wed, 18 Apr 2018 11:56:03 -0300
Eduardo Habkost <ehabkost@redhat.com> wrote:

> On Wed, Apr 18, 2018 at 04:28:03PM +0200, Igor Mammedov wrote:
> > By default MachineClass::get_hotplug_handler is NULL and concrete board
> > should set it to it's own handler.
> > Considering there isn't any default handler, drop saving empty
> > MachineClass::get_hotplug_handler in child class and make PC code
> > consistent with spapr/s390x boards.
> > 
> > We can bring this back when actual usecase surfaces and do it
> > consistently across boards that use get_hotplug_handler().
> > 
> > Suggested-by: David Gibson <david@gibson.dropbear.id.au>
> > Signed-off-by: Igor Mammedov <imammedo@redhat.com>  
> 
> Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
> 
> 
> [...]
> > @@ -2344,7 +2341,6 @@ static void pc_machine_class_init(ObjectClass *oc, void *data)
> >      HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(oc);
> >      NMIClass *nc = NMI_CLASS(oc);
> >  
> > -    pcmc->get_hotplug_handler = mc->get_hotplug_handler;  
> 
> What about assert(!mc->get_hotplug_handler) just before
> overwriting it?
I'll make it patch on top of series to make sure that
every board that sets get_hotplug_handler will do it
consistently.