Re: [Intel IOMMU][patch 8/8] Preserve some Virtual Address when devices cannot address entire range.

[Andi Kleen]

On Tuesday 24 April 2007 22:33:04 Ashok Raj wrote:

> With PCIE there is some benefit to keep dma addr low for performance reasons, 
> since it will use 	32bit Transaction level packets instead of 64bit.
> 
> This reservation is only required if we have some legacy device under a p2p 
> where its required to share its addr space with other devices. We could 
> implement a default when one is not specified to keep things simple.

We already have a couple of other IOMMU architectures who essentially have the same
problem. Have you checked how they solve this?

-Andi



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