Messages in this thread | | | Date | Sun, 25 May 2008 10:20:11 +0300 | From | Muli Ben-Yehuda <> | Subject | Re: [PATCH v2 -mm 0/2] x86: per-device dma_mapping_ops |
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On Thu, May 22, 2008 at 04:13:02PM +0530, Amit Shah wrote:
> OK; this sounds helpful. the hook can make a hypercall and confirm > with the host kernel if the device in question is an assigned > physical device. If yes, we replace the dma_ops. Though, the > original intent of having stackable ops is that we might want to go > through the swiotlb in the guest even for an assigned device if the > guest dma addresses are not in the addressable range of the guest > chipset. > > > created (it works with hot plugging). It enables IOMMUs to set up an > > appropriate dma_mapping_ops per device. > > From what we've discussed so far, it looks like stackable dma ops will > definitely be needed. Does this patchset provide something that stacking > won't?
Yes---this patchset let's you have a per-device dma-ops, whereas with stackable you only get global dma-ops. I think it's clear we need both, and I think per-device dma-ops are the first thing that's needed. Stacking can then be introduced on a per-device basis.
Cheers, Muli
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