Re: [Qemu-devel] Re: [RFC PATCH 4/7] ide: IOMMU support

[Chris Wright]

* Avi Kivity (address@hidden) wrote:
> On 07/15/2010 08:17 PM, Chris Wright wrote:
> >
> >>For emulated device, it seems like we can ignore ATS completely, no?
> >Not if you want to emulate an ATS capable device ;)
> 
> What I meant was that the whole request translation, invalidate, dma
> using a translated address thing is invisible to software.  We can
> emulate an ATS capable device by going through the iommu every time.

Well, I don't see any reason to completely ignore it.  It'd be really
useful for testing (I'd use it that way).  Esp to verify the
invalidation of the device IOTLBs.

But I think it's not a difficult thing to emulate once we have a proper
api encapsulating a device's dma request.

thanks,
-chris