Re: [Qemu-devel] [PATCH 4/8] Add universal DMA helper functions

[Eduard - Gabriel Munteanu]

On Mon, Feb 27, 2012 at 12:33:49PM +0200, Michael S. Tsirkin wrote:
> On Mon, Feb 27, 2012 at 11:22:43AM +1100, David Gibson wrote:
> > On Sun, Feb 26, 2012 at 12:04:49PM +0200, Michael S. Tsirkin wrote:
> > > On Fri, Feb 24, 2012 at 02:27:39PM +1100, David Gibson wrote:

[snip]

> > > 
> > > I'm a bit confused with all the stubbing going on.
> > > Is this the final form of the pci_* functions or just
> > > a stub? If the final form, we probably should just
> > > open-code them - they don't buy us much.
> > > If not, let's add a comment?
> > 
> > Well.. it's the intended final form of pci_dma_*() - which do become
> > trivial wrappers, yes.
> 
> I'd say let's drop them then (in a follow-up patch).  The topic is
> confusing enough without having to wade through layers of wrappers :)
>

Drop them how? Using dma_* stuff directly? That might work, but I
remember others suggesting we should use a specialized PCI wrapper.
Perhaps it makes sense if some other bus, or PCI itself at some point,
needs to do something special.

> > It's _not_ the intended final form of dma_*(),
> > which need to grow code to do actual IOMMU translation.  I'll add a
> > comment about this in the next round.
> > 
> > -- 
> > David Gibson                        | I'll have my music baroque, and my 
> > code
> > david AT gibson.dropbear.id.au      | minimalist, thank you.  NOT _the_ 
> > _other_
> >                             | _way_ _around_!
> > http://www.ozlabs.org/~dgibson