Messages in this thread | | | Date | Mon, 1 Dec 2008 15:07:11 +0100 | From | Joerg Roedel <> | Subject | Re: [PATCH 3/9] add frontend implementation for the IOMMU API |
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On Mon, Dec 01, 2008 at 03:02:09PM +0200, Muli Ben-Yehuda wrote: > On Mon, Dec 01, 2008 at 01:00:26PM +0100, Joerg Roedel wrote: > > > > > > The majority of the names (include/linux/iommu.h, iommu.c, > > > > > iommu_ops, etc) looks too generic? We already have lots of > > > > > similar things (e.g. arch/{x86,ia64}/asm/iommu.h, several > > > > > archs' iommu.c, etc). Such names are expected to be used by > > > > > all the IOMMUs. > > > > > > > > The API is already useful for more than KVM. I also plan to > > > > extend it to support more types of IOMMUs than VT-d and AMD > > > > IOMMU in the future. But these changes are more intrusive than > > > > this patchset and need more discussion. I prefer to do small > > > > steps into this direction. > > > > > > Can you be more specific? What IOMMU could use this? For example, > > > how GART can use this? I think that people expect the name 'struct > > > iommu_ops' to be an abstract for all the IOMMUs (or the majority > > > at least). If this works like that, the name is a good choice, I > > > think. > > > > GART can't use exactly this. But with some extensions we can make it > > useful for GART and GART-like IOMMUs too. For example we can emulate > > domains in GART by partitioning the GART aperture space. > > That would only work with a pvdma API, since GART doesn't support > multiple address spaces, and you don't get the isolation properties of > a real IOMMU, so... why would you want to do that?
Yes, this can not be used for not-pv device passthrough. But I think it can speed up the pvdma case. Beside that I can be used for UIO and devices which perform bad with sg.
Joerg
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