Re: [Qemu-devel] [PATCH 01/10] Add stub functions for PCI device models to do PCI DMA

[Avi Kivity]

On 09/01/2011 07:05 PM, Anthony Liguori wrote:
> > I think the patchset is fine. It routes all access through pci_dma_rw(),
> > which accepts a PCIDevice. We can later define pci_dma_rw() in terms of
> > the memory API and get the benefit of the memory hierarchy.
>
>
> The challenge is what you do about something like ne2k where the core 
> chipset can either be a PCI device or an ISA device.  You would have 
> to implement a wrapper around pci_dma_rw() in order to turn it into 
> cpu_physical_memory_rw when doing ISA.

True.  But I still think it's the right thing.

We can't really pass a MemoryRegion as the source address, since there 
is no per-device MemoryRegion.  We can use pci_address_space() for basic 
offsetting, and for bypassing bridge windows, but iommu source detection 
has to use the PCIDevice directly.

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