Re: [PATCH] hw/pci: Avoid adding PCI devices to the "unattached" QOM tree node

[Igor Mammedov <imammedo@redhat.com>]

On Thu, 19 Feb 2026 16:06:41 +0100
Igor Mammedov <imammedo@redhat.com> wrote:

> On Tue, 17 Feb 2026 07:55:12 +0100
> Thomas Huth <thuth@redhat.com> wrote:
> 
> > From: Thomas Huth <thuth@redhat.com>
> > 
> > PCI devices that are added via pci_create_simple_multifunction(),
> > pci_create_simple() or pci_init_nic_in_slot() currently show up
> > under "/machine/unattached" in the QOM tree. This is somewhat ugly,
> > the parent should rather be the PCI bus node instead, so let's add
> > the proper relation here.
> > 
> > Signed-off-by: Thomas Huth <thuth@redhat.com>
> > ---
> >  hw/pci/pci.c | 14 ++++++++++++++
> >  1 file changed, 14 insertions(+)
> > 
> > diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> > index 90d6d71efdc..2f4d2be50fd 100644
> > --- a/hw/pci/pci.c
> > +++ b/hw/pci/pci.c
> > @@ -2071,6 +2071,15 @@ const pci_class_desc *get_class_desc(int class)
> >      return desc;
> >  }
> >  
> > +static void pci_dev_property_add_child(PCIBus *bus, const char *name,
> > +                                       PCIDevice *dev)
> > +{
> > +    g_autofree char *childname = g_strdup_printf("%s[%d.%d]", name,
> > +                                                 PCI_SLOT(dev->devfn),
> > +                                                 PCI_FUNC(dev->devfn));
> > +    object_property_add_child(OBJECT(bus), childname, OBJECT(dev));
> > +}
> > +
> >  void pci_init_nic_devices(PCIBus *bus, const char *default_model)
> >  {
> >      qemu_create_nic_bus_devices(&bus->qbus, TYPE_PCI_DEVICE, default_model,
> > @@ -2114,6 +2123,7 @@ bool pci_init_nic_in_slot(PCIBus *rootbus, const char *model,
> >  
> >      pci_dev = pci_new(devfn, model);  
> there are a few more places that have similar pattern, should we fix them to?
> 
> >      qdev_set_nic_properties(&pci_dev->qdev, nd);
> > +    pci_dev_property_add_child(bus, model, pci_dev);  
> 
> >      pci_realize_and_unref(pci_dev, bus, &error_fatal);  
> this one also takes bus as an argument, and then goes down to
>  qdev_realize_and_unref->qdev_realize->qdev_set_parent_bus->bus_add_child
> that eventually creates a link to device.
> 
> wouldn't pci_dev_property_add_child() create a duplicate entry
> as a child with different name component there?
> 
> another question, should we 'fix' qdev_set_parent_bus->bus_add_child
> to add a child instead of a link? That would do what patch intends
> but consistently for all devices with parent bus.

and then this rises a question if the bus should be a parent or
the owner of the bus is the parent?

> 
> 
> >      return true;
> >  }
> > @@ -2412,6 +2422,8 @@ PCIDevice *pci_create_simple_multifunction(PCIBus *bus, int devfn,
> >                                             const char *name)
> >  {
> >      PCIDevice *dev = pci_new_multifunction(devfn, name);
> > +
> > +    pci_dev_property_add_child(bus, name, dev);
> >      pci_realize_and_unref(dev, bus, &error_fatal);
> >      return dev;
> >  }
> > @@ -2419,6 +2431,8 @@ PCIDevice *pci_create_simple_multifunction(PCIBus *bus, int devfn,
> >  PCIDevice *pci_create_simple(PCIBus *bus, int devfn, const char *name)
> >  {
> >      PCIDevice *dev = pci_new(devfn, name);
> > +
> > +    pci_dev_property_add_child(bus, name, dev);
> >      pci_realize_and_unref(dev, bus, &error_fatal);
> >      return dev;
> >  }  
>