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pci: Introduce helper to retrieve a PCI device's DMA address space 

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>
This commit is contained in:
Alexey Kardashevskiy 2013-08-10 01:09:08 +10:00 committed by Michael S. Tsirkin
parent 1ae2757c6c
commit 9eda7d373e
2 changed files with 19 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
hw/pci/pci.c
View File

@ -812,12 +812,7 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus,
}
pci_dev->bus = bus;
if (bus->iommu_fn) {
dma_as = bus->iommu_fn(bus, bus->iommu_opaque, devfn);
} else {
/* FIXME: inherit memory region from bus creator */
dma_as = &address_space_memory;
}
dma_as = pci_device_iommu_address_space(pci_dev);
memory_region_init_alias(&pci_dev->bus_master_enable_region,
OBJECT(pci_dev), "bus master",
@ -2239,6 +2234,23 @@ static void pci_device_class_init(ObjectClass *klass, void *data)
k->props = pci_props;
}
AddressSpace *pci_device_iommu_address_space(PCIDevice *dev)
{
PCIBus *bus = PCI_BUS(dev->bus);
if (bus->iommu_fn) {
return bus->iommu_fn(bus, bus->iommu_opaque, dev->devfn);
}
if (bus->parent_dev) {
/** We are ignoring the bus master DMA bit of the bridge
* as it would complicate things such as VFIO for no good reason */
return pci_device_iommu_address_space(bus->parent_dev);
}
return &address_space_memory;
}
void pci_setup_iommu(PCIBus *bus, PCIIOMMUFunc fn, void *opaque)
{
bus->iommu_fn = fn;

1
include/hw/pci/pci.h
View File

@ -405,6 +405,7 @@ void pci_device_deassert_intx(PCIDevice *dev);
typedef AddressSpace *(*PCIIOMMUFunc)(PCIBus *, void *, int);
AddressSpace *pci_device_iommu_address_space(PCIDevice *dev);
void pci_setup_iommu(PCIBus *bus, PCIIOMMUFunc fn, void *opaque);
static inline void