Re: [PATCH v2 12/58] qdev: Convert uses of qdev_set_parent_bus() manually

[Markus Armbruster]

Philippe Mathieu-Daudé <philmd@redhat.com> writes:

> On 5/29/20 3:44 PM, Markus Armbruster wrote:
>> Same transformation as in the previous commit.  Manual, because
>> convincing Coccinelle to transform these cases is somewhere between
>> not worthwhile and infeasible (at least for me).
>> 
>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>> ---
>>  hw/pci-host/prep.c |  3 +--
>>  hw/ppc/pnv.c       |  6 ++----
>>  hw/s390x/sclp.c    | 10 ++++------
>>  3 files changed, 7 insertions(+), 12 deletions(-)
>> 
>> diff --git a/hw/pci-host/prep.c b/hw/pci-host/prep.c
>> index c821ef889d..42c7e63a60 100644
>> --- a/hw/pci-host/prep.c
>> +++ b/hw/pci-host/prep.c
>> @@ -268,7 +268,7 @@ static void raven_pcihost_realizefn(DeviceState *d, 
>> Error **errp)
>>      memory_region_add_subregion(address_space_mem, 0xbffffff0, 
>> &s->pci_intack);
>>  
>>      /* TODO Remove once realize propagates to child devices. */
>> -    object_property_set_bool(OBJECT(&s->pci_dev), true, "realized", errp);
>> +    qdev_realize(DEVICE(&s->pci_dev), BUS(&s->pci_bus), errp);
>>  }
>>  
>>  static void raven_pcihost_initfn(Object *obj)
>> @@ -308,7 +308,6 @@ static void raven_pcihost_initfn(Object *obj)
>>  
>>      object_initialize(&s->pci_dev, sizeof(s->pci_dev), 
>> TYPE_RAVEN_PCI_DEVICE);
>>      pci_dev = DEVICE(&s->pci_dev);
>> -    qdev_set_parent_bus(pci_dev, BUS(&s->pci_bus));
>>      object_property_set_int(OBJECT(&s->pci_dev), PCI_DEVFN(0, 0), "addr",
>>                              NULL);
>>      qdev_prop_set_bit(pci_dev, "multifunction", false);
>> diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
>> index 8562af3fe0..e0588285a2 100644
>> --- a/hw/ppc/pnv.c
>> +++ b/hw/ppc/pnv.c
>> @@ -1212,12 +1212,11 @@ static void pnv_chip_power8_realize(DeviceState 
>> *dev, Error **errp)
>>          object_property_set_int(OBJECT(phb), i, "index", &error_fatal);
>>          object_property_set_int(OBJECT(phb), chip->chip_id, "chip-id",
>>                                  &error_fatal);
>> -        object_property_set_bool(OBJECT(phb), true, "realized", &local_err);
>> +        qdev_realize(DEVICE(phb), NULL, &local_err);
>>          if (local_err) {
>>              error_propagate(errp, local_err);
>>              return;
>>          }
>> -        qdev_set_parent_bus(DEVICE(phb), sysbus_get_default());
>>  
>>          /* Populate the XSCOM address space. */
>>          pnv_xscom_add_subregion(chip,
>> @@ -1422,12 +1421,11 @@ static void pnv_chip_power9_phb_realize(PnvChip 
>> *chip, Error **errp)
>>              object_property_set_int(obj, PNV_PHB4_DEVICE_ID, "device-id",
>>                                      &error_fatal);
>>              object_property_set_link(obj, OBJECT(stack), "stack", 
>> &error_abort);
>> -            object_property_set_bool(obj, true, "realized", &local_err);
>> +            qdev_realize(DEVICE(obj), NULL, &local_err);
>>              if (local_err) {
>>                  error_propagate(errp, local_err);
>>                  return;
>>              }
>> -            qdev_set_parent_bus(DEVICE(obj), sysbus_get_default());
>>  
>>              /* Populate the XSCOM address space. */
>>              pnv_xscom_add_subregion(chip,
>> diff --git a/hw/s390x/sclp.c b/hw/s390x/sclp.c
>> index 20aca30ac4..40e27a8cb4 100644
>> --- a/hw/s390x/sclp.c
>> +++ b/hw/s390x/sclp.c
>> @@ -333,17 +333,15 @@ static void sclp_realize(DeviceState *dev, Error 
>> **errp)
>>      uint64_t hw_limit;
>>      int ret;
>>  
>> -    object_property_set_bool(OBJECT(sclp->event_facility), true, "realized",
>> -                             &err);
>> -    if (err) {
>> -        goto out;
>> -    }
>>      /*
>>       * qdev_device_add searches the sysbus for TYPE_SCLP_EVENTS_BUS. As long
>>       * as we can't find a fitting bus via the qom tree, we have to add the
>>       * event facility to the sysbus, so e.g. a sclp console can be created.
>>       */
>> -    qdev_set_parent_bus(DEVICE(sclp->event_facility), sysbus_get_default());
>> +    qdev_realize(DEVICE(sclp->event_facility), NULL, &err);
>
> I agree with the API change, but I find using sysbus_get_default() way
> clearer than using NULL. I'v go the other way around, replace bus=NULL
> by an explicit bus=sysbus_get_default() in our codebase.

I agree with you on sysbus_get_default() being clearer than NULL.  I
actually get rid of NULL in this series, but it takes me many more
patches to get there.  Starts at PATCH 45.

Of course, I must not expect reviewers to look three dozen patches
ahead.

> Can be done later, I know... But we can also keep sysbus_get_default()
> in this patch ;)

This patch's purpose is getting rid of separate qdev_set_parent_bus(),
in part to ease the conversion from qdev_realize() to sysbus_realize().

> Whichever you prefer (mine is keeping it):
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Thanks!

>
>> +    if (err) {
>> +        goto out;
>> +    }
>>  
>>      ret = s390_set_memory_limit(machine->maxram_size, &hw_limit);
>>      if (ret == -E2BIG) {
>>