On Sun, Jun 23, 2013 at 09:28:13AM +1000, Benjamin Herrenschmidt wrote: > On Sat, 2013-06-22 at 22:03 +1000, David Gibson wrote: > > I think the interface should not take the group fd, but the container > > fd. Holding a reference to *that* would keep the necessary things > > around. But more to the point, it's the right thing semantically: > > > > The container is essentially the handle on a host iommu address space, > > and so that's what should be bound by the KVM call to a particular > > guest iommu address space. e.g. it would make no sense to bind two > > different groups to different guest iommu address spaces, if they were > > in the same container - the guest thinks they are different spaces, > > but if they're in the same container they must be the same space. > > Interestingly, how are we going to extend that when/if we implement > DDW ? > > DDW means an API by which the guest can request the creation of > additional iommus for a given device (typically, in addition to the > default smallish 32-bit one using 4k pages, the guest can request > a larger window in 64-bit space using a larger page size). So, would a PAPR gest requesting this expect the new window to have a new liobn, or an existing liobn? -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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