Messages in this thread | | | Date | Thu, 15 May 2008 11:30:12 +0200 | From | Andi Kleen <> | Subject | Re: [PATCH 0/2] x86: per-device dma_mapping_ops |
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FUJITA Tomonori wrote: > On Thu, 15 May 2008 11:01:09 +0200 > Andi Kleen <andi@firstfloor.org> wrote: > >> FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> writes: >> >>> This patchset adds per-device dma_mapping_ops support for >>> CONFIG_X86_64 like POWER architecture does. This change enables us to >>> cleanly fix the Calgary IOMMU issue that some devices are not behind >>> the IOMMU [1]. It also would be helpful to handle KVM PCI passthrough. >> This makes it basically impossible to do stack ops, which some >> people have been doing. > > Seems that I misunderstand what those people want. > > What those people want to do and how the stack ops achieve it? Or can > you tell me where their patches are?
I've seen it in two cases: first was for KVM IO bypass and the other was a (unfinished) patch to support the NoDMA bitmaps on some systems.
In this case you really want to do a wrapper around the existing ops and extend the mapping.
That worked fine by just replacing the global pointer, but will be quite hard in your set up.
-Andi
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