Re: [PATCH v2 3/3] pci: Fix wrong parameter passing to pci_device_get_iommu_bus_devfn()

["Cédric Le Goater" <clg@redhat.com>]

On 9/29/25 05:42, Zhenzhong Duan wrote:
> The 2nd parameter of pci_device_get_iommu_bus_devfn() about root PCIBus
> backed by an IOMMU for the PCI device, the 3rd is about aliased PCIBus
> of the PCI device.
> 
> Meanwhile the 3rd and 4th parameters are optional, pass NULL if they
> are not needed.
> 
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>

The commit log should mention potential consequences of this change.

Will this fix need to be backported ? up to ~9.1


Thanks,

C.



> ---
>   hw/pci/pci.c | 18 ++++++++----------
>   1 file changed, 8 insertions(+), 10 deletions(-)
> 
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index c3df9d6656..d5ed89aab7 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -2967,7 +2967,7 @@ int pci_iommu_init_iotlb_notifier(PCIDevice *dev, IOMMUNotifier *n,
>       PCIBus *iommu_bus;
>       int devfn;
>   
> -    pci_device_get_iommu_bus_devfn(dev, &bus, &iommu_bus, &devfn);
> +    pci_device_get_iommu_bus_devfn(dev, &iommu_bus, &bus, &devfn);
>       if (iommu_bus && iommu_bus->iommu_ops->init_iotlb_notifier) {
>           iommu_bus->iommu_ops->init_iotlb_notifier(bus, iommu_bus->iommu_opaque,
>                                                     devfn, n, fn, opaque);
> @@ -3025,7 +3025,7 @@ int pci_pri_request_page(PCIDevice *dev, uint32_t pasid, bool priv_req,
>           return -EPERM;
>       }
>   
> -    pci_device_get_iommu_bus_devfn(dev, &bus, &iommu_bus, &devfn);
> +    pci_device_get_iommu_bus_devfn(dev, &iommu_bus, &bus, &devfn);
>       if (iommu_bus && iommu_bus->iommu_ops->pri_request_page) {
>           return iommu_bus->iommu_ops->pri_request_page(bus,
>                                                        iommu_bus->iommu_opaque,
> @@ -3049,7 +3049,7 @@ int pci_pri_register_notifier(PCIDevice *dev, uint32_t pasid,
>           return -EPERM;
>       }
>   
> -    pci_device_get_iommu_bus_devfn(dev, &bus, &iommu_bus, &devfn);
> +    pci_device_get_iommu_bus_devfn(dev, &iommu_bus, &bus, &devfn);
>       if (iommu_bus && iommu_bus->iommu_ops->pri_register_notifier) {
>           iommu_bus->iommu_ops->pri_register_notifier(bus,
>                                                       iommu_bus->iommu_opaque,
> @@ -3066,7 +3066,7 @@ void pci_pri_unregister_notifier(PCIDevice *dev, uint32_t pasid)
>       PCIBus *iommu_bus;
>       int devfn;
>   
> -    pci_device_get_iommu_bus_devfn(dev, &bus, &iommu_bus, &devfn);
> +    pci_device_get_iommu_bus_devfn(dev, &iommu_bus, &bus, &devfn);
>       if (iommu_bus && iommu_bus->iommu_ops->pri_unregister_notifier) {
>           iommu_bus->iommu_ops->pri_unregister_notifier(bus,
>                                                         iommu_bus->iommu_opaque,
> @@ -3098,7 +3098,7 @@ ssize_t pci_ats_request_translation(PCIDevice *dev, uint32_t pasid,
>           return -EPERM;
>       }
>   
> -    pci_device_get_iommu_bus_devfn(dev, &bus, &iommu_bus, &devfn);
> +    pci_device_get_iommu_bus_devfn(dev, &iommu_bus, &bus, &devfn);
>       if (iommu_bus && iommu_bus->iommu_ops->ats_request_translation) {
>           return iommu_bus->iommu_ops->ats_request_translation(bus,
>                                                        iommu_bus->iommu_opaque,
> @@ -3122,7 +3122,7 @@ int pci_iommu_register_iotlb_notifier(PCIDevice *dev, uint32_t pasid,
>           return -EPERM;
>       }
>   
> -    pci_device_get_iommu_bus_devfn(dev, &bus, &iommu_bus, &devfn);
> +    pci_device_get_iommu_bus_devfn(dev, &iommu_bus, &bus, &devfn);
>       if (iommu_bus && iommu_bus->iommu_ops->register_iotlb_notifier) {
>           iommu_bus->iommu_ops->register_iotlb_notifier(bus,
>                                              iommu_bus->iommu_opaque, devfn,
> @@ -3144,7 +3144,7 @@ int pci_iommu_unregister_iotlb_notifier(PCIDevice *dev, uint32_t pasid,
>           return -EPERM;
>       }
>   
> -    pci_device_get_iommu_bus_devfn(dev, &bus, &iommu_bus, &devfn);
> +    pci_device_get_iommu_bus_devfn(dev, &iommu_bus, &bus, &devfn);
>       if (iommu_bus && iommu_bus->iommu_ops->unregister_iotlb_notifier) {
>           iommu_bus->iommu_ops->unregister_iotlb_notifier(bus,
>                                                           iommu_bus->iommu_opaque,
> @@ -3158,11 +3158,9 @@ int pci_iommu_unregister_iotlb_notifier(PCIDevice *dev, uint32_t pasid,
>   int pci_iommu_get_iotlb_info(PCIDevice *dev, uint8_t *addr_width,
>                                uint32_t *min_page_size)
>   {
> -    PCIBus *bus;
>       PCIBus *iommu_bus;
> -    int devfn;
>   
> -    pci_device_get_iommu_bus_devfn(dev, &bus, &iommu_bus, &devfn);
> +    pci_device_get_iommu_bus_devfn(dev, &iommu_bus, NULL, NULL);
>       if (iommu_bus && iommu_bus->iommu_ops->get_iotlb_info) {
>           iommu_bus->iommu_ops->get_iotlb_info(iommu_bus->iommu_opaque,
>                                                addr_width, min_page_size);