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

[Cédric Le Goater]

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.d...@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);