[PATCH v8] KVM: PPC: reserve a capability and ioctl numbers for realmode VFIO

Benjamin Herrenschmidt benh at kernel.crashing.org
Wed Aug 28 11:26:31 EST 2013

On Wed, 2013-08-28 at 10:51 +1000, Alexey Kardashevskiy wrote:
> The ioctl I made up is basically a copy of KVM_CREATE_SPAPR_TCE which does
> the same thing for emulated devices and it is there for quite a while but
> it is not really extensible. And these two ioctls share some bits of code.
> Now we will have 2 pieces of code which do almost the same thing but in a
> different way. Kinda sucks :(

Right. Thus the question, Gleb, we can either:

 - Keep Alexey patch as-is allowing us to *finally* merge that stuff
that's been around for monthes

 - Convert *both* existing TCE objects to the new 
KVM_CREATE_DEVICE, and have some backward compat code for the old one.

I don't think it makes sense to have the "emulated TCE" and "IOMMU TCE"
objects use a fundamentally different API and infrastructure.

> >> So my stuff is not going to upstream again. Heh. Ok. I'll implement it.
> >>
> > Thanks! Should I keep KVM_CAP_SPAPR_MULTITCE capability patch or can I
> > drop it for now?
> Please keep it, it is unrelated to the IOMMU-VFIO thing.

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