Re: [Qemu-devel] [PATCH] hw/pci: ensure that only PCI/PCIe bridges can be attached to pxb/pxb-pcie devices

[Laszlo Ersek]

On 01/18/16 16:27, Marcel Apfelbaum wrote:
> PCI devices can't be plugged directly into PCI extra root bridges
> because their resources can't be computed by firmware before the ACPI
> tables are loaded.
> 
> Signed-off-by: Marcel Apfelbaum <address@hidden>
> ---
> 
> Hi,
> 
> This patch follows the discussion:
> https://lists.gnu.org/archive/html/qemu-devel/2016-01/msg01484.html
> 
> Thanks,
> Marcel
>     
>  hw/pci/pci.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index 168b9cc..584f504 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -850,6 +850,13 @@ static PCIDevice *do_pci_register_device(PCIDevice 
> *pci_dev, PCIBus *bus,
>      DeviceState *dev = DEVICE(pci_dev);
>  
>      pci_dev->bus = bus;
> +    /* Only pci bridges can be attached to extra PCI root buses */
> +    if (pci_bus_is_root(bus) && bus->parent_dev && !pc->is_bridge) {
> +        error_setg(errp,
> +                   "PCI: Only PCI/PCIe bridges can be plugged into %s",
> +                    bus->parent_dev->name);
> +        return NULL;
> +    }
>  
>      if (devfn < 0) {
>          for(devfn = bus->devfn_min ; devfn < ARRAY_SIZE(bus->devices);
> 

Looks sensible to me (and the commit message actually enlightens me a
bit :)), but you could very easily trick me in this area, so I'll leave
formal review to others. :)

Laszlo