Re: IOMMU and graphics cards

[Joerg Roedel <joerg.roedel@amd.com>]

On Thu, May 07, 2009 at 11:22:01AM +0100, David Woodhouse wrote:
> On Thu, 2009-05-07 at 12:01 +0200, Joerg Roedel wrote:
> > > Looks like the DRM code uses the DMA API.
> > 
> > The proprietary drivers make problems so far. For the ATI one I am in
> > contact with the developers to try to fix it. But I can't do anything
> > about the other proprietary driver I am aware of :-(
> 
> I see no harm in "breaking" code which was already broken. If that's the
> only reason we're enabling the graphics workaround, let's turn it off.

Well, it is not that simple. Having no workaround at all will not result
in working proprietary drivers. More likely is that distros just disable
the IOMMU because their customers want to use these drivers for working
3d acceleration.
As I wrote in the original mail I think we should just make sure that
these drivers still work with an IOMMU without disabling device
isolation.

Joerg

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