Re: [Qemu-devel] [PATCH 1/5] PCI DMA API (v3)

[Blue Swirl]

On 4/16/08, Anthony Liguori <address@hidden> wrote:
> This patch introduces a DMA API and plumbs support through the DMA layer.  We
>  use a mostly opaque structure, IOVector to represent a scatter/gather list of
>  physical memory.  Associated with each IOVector is a read/write function and
>  an opaque pointer.  This allows arbitrary transformation/mapping of the
>  data while providing an easy mechanism to short-cut the zero-copy case
>  in the block/net backends.

This looks much better also for Sparc uses. I converted pcnet to use
the IOVectors (see patch), it does not work yet but looks doable.

IMHO the read/write functions should be a property of the bus so that
they are hidden from the device, for pcnet it does not matter as we
have to do the swapping anyway.

pcnet_dma_api.diff
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