Re: [Xen-devel] VP problematic for backend drivers on IA64?

[Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>]

On 25 Jan 2006, at 16:46, Muli Ben-Yehuda wrote:

> That's a good point. Since Xen provides its own "IOMMU" (swiotlb at
> the moment), I think we should set PCI_DMA_BUS_IS_PHYS so that the
> block layer never does bounce buffers on its own - unless doing it
> there is more efficient?
We set it to zero if using swiotlb. I think setting it to zero disables 
driver-specific bounce buffer code?
> As for drivers that don't use DMA - we only care about
> para-virtualized drivers. I doubt we'll see any PV drivers where the
> real drivers don't do DMA.
That's a big assumption that may only be 99.9% correct. :-)

 -- Keir


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