On Tue, Jul 08, 2025 at 04:40:50PM +0100, Shameer Kolothum wrote:
> @@ -2909,6 +2909,19 @@ static void pci_device_get_iommu_bus_devfn(PCIDevice
> *dev,
> }
> }
>
> + /*
> + * When multiple PCI Express Root Buses are defined using pxb-pcie,
> + * the IOMMU configuration may be specific to each root bus. However,
> + * pxb-pcie acts as a special root complex whose parent is
> effectively
> + * the default root complex(pcie.0). Ensure that we retrieve the
> + * correct IOMMU ops(if any) in such cases.
> + */
> + if (pci_bus_is_express(iommu_bus) && pci_bus_is_root(iommu_bus)) {
> + if (!iommu_bus->iommu_per_bus && parent_bus->iommu_per_bus) {
> + break;
Mind elaborating why the current bus must unset iommu_per_bus while
its parent sets iommu_per_bus?
My understanding is that for a pxb-pcie we should set iommu_per_bus
but for its parent (the default root complex) we should unset its
iommu_per_bus?
Thanks
Nicolin
