[Qemu-devel] [PATCH 5/8] pci: Introduce helper to retrieve a PCI device's DMA address space

[David Gibson <david@gibson.dropbear.id.au>]

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.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 hw/pci/pci.c         |    9 ++++++++-
 include/hw/pci/pci.h |    1 +
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 39085d8..e7a9735 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -811,7 +811,7 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus,
     }
 
     pci_dev->bus = bus;
-    dma_as = bus->iommu_fn(bus, bus->iommu_opaque, devfn);
+    dma_as = pci_iommu_as(pci_dev);
     memory_region_init_alias(&pci_dev->bus_master_enable_region, "bus master",
                              dma_as->root, 0, memory_region_size(dma_as->root));
     memory_region_set_enabled(&pci_dev->bus_master_enable_region, false);
@@ -2233,6 +2233,13 @@ static void pci_device_class_init(ObjectClass *klass, void *data)
     k->props = pci_props;
 }
 
+AddressSpace *pci_iommu_as(PCIDevice *dev)
+{
+    PCIBus *bus = PCI_BUS(dev->bus);
+
+    return bus->iommu_fn(bus, bus->iommu_opaque, dev->devfn);
+}
+
 void pci_setup_iommu(PCIBus *bus, PCIIOMMUFunc fn, void *opaque)
 {
     bus->iommu_fn = fn;
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index 6ef1f97..21e2132 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -402,6 +402,7 @@ void pci_device_deassert_intx(PCIDevice *dev);
 
 typedef AddressSpace *(*PCIIOMMUFunc)(PCIBus *, void *, int);
 
+AddressSpace *pci_iommu_as(PCIDevice *dev);
 void pci_setup_iommu(PCIBus *bus, PCIIOMMUFunc fn, void *opaque);
 
 static inline void
-- 
1.7.10.4