Re: [PATCH 3/9] add frontend implementation for the IOMMU API

[Joerg Roedel]

On Tue, Dec 02, 2008 at 12:58:29AM +0900, FUJITA Tomonori wrote:
> On Mon, 01 Dec 2008 16:33:11 +0200
> Avi Kivity <avi@xxxxxxxxxx> wrote:
> 
> > Joerg Roedel wrote:
> > > Hmm, is there any hardware IOMMU with which we can't emulate domains by
> > > partitioning the IO address space? This concept works for GART and
> > > Calgary.
> > >
> > >   
> > 
> > Is partitioning secure?  Domain X's user could program its hardware to 
> > dma to domain Y's addresses, zapping away Domain Y's user's memory.
> 
> It can't be secure. So what's the point to emulate the domain
> partitioning in many traditional hardware IOMMUs that doesn't support
> it.

Btw, if you use the k8-agp driver the GART space is already partitioned
today. So this concept is not entirely new.

Joerg

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