Re: IOMMU and graphics cards

Joerg Roedel
2009-07-07T08:54:23Z

On Tue, Jul 07, 2009 at 08:00:01AM +1000, Dave Airlie wrote:
>
> Could you also enumerate any limitations of the IOMMUs on the amount
> of memory they can remap per device if any.

The AMD IOMMU driver in 2.6.31-rcX can map up to 4GB per domain. If the
gfx card has a domain of its own it can use all of the 4GB.
I am not 100% sure about VT-d, but as far as I understood the allocator
it doesn't have that 4GB limitation per domain.

Joerg

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