Re: [kvm-devel] [PATCH 3/8] KVM: PVDMA Guest: Guest-side routines for paravirtualized DMA

Amit Shah
2007-11-12T11:57:08Z

On Monday 12 November 2007 16:20:01 Muli Ben-Yehuda wrote:
> On Wed, Nov 07, 2007 at 04:21:04PM +0200, Amit Shah wrote:
> > We make the dma_mapping_ops structure to point to our structure so
> > that every DMA access goes through us. (This is the reason this only
> > works for 64-bit guest. 32-bit guest doesn't yet have a dma_ops
> > struct.)
>
> I need the same facility for Calgary for falling back to swiotlb if a
> translation is disabled on some slot, and IB needs the same facility
> for some IB adapters (e.g., ipath). Perhaps it's time to consider
> stackable dma-ops (unless someone has a better idea...).

That would make great sense and simplify implementations.

How do you propose such an implementation? An array of function pointers for
each possible call?

>
> Cheers,
> Muli

Amit.