A PCI device's DMA address space (possibly an IOMMU) is returned by a
method on the PCIBus. At the moment that only has one caller, so the
method is simply open coded. We'll need another caller for VFIO, so
this patch introduces a helper/wrapper function.
If IOMMU is not set, the pci_device_iommu_address_space() function
returns the parent's IOMMU skipping the "bus master" address space as
otherwise proper emulation would require more effort for no benefit.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
[aik: added inheritance from parent if iommu is not set for the current bus]
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
9eda7d373e