Re: IOMMU and graphics cards

[Joerg Roedel]

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

-- 
           | Advanced Micro Devices GmbH
 Operating | Karl-Hammerschmidt-Str. 34, 85609 Dornach bei München
 System    | 
 Research  | Geschäftsführer: Thomas M. McCoy, Giuliano Meroni
 Center    | Sitz: Dornach, Gemeinde Aschheim, Landkreis München
           | Registergericht München, HRB Nr. 43632

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/