Commit 9eda7d37 authored by Alexey Kardashevskiy's avatar Alexey Kardashevskiy Committed by Michael S. Tsirkin
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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: default avatarDavid Gibson <david@gibson.dropbear.id.au>
[aik: added inheritance from parent if iommu is not set for the current bus]
Signed-off-by: default avatarAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 1ae2757c

hw/pci/pci.c

+18 −6
Original line number Diff line number Diff line
@@ -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;

include/hw/pci/pci.h

+1 −0
Original line number Diff line number Diff line
@@ -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