On Fri, May 29, 2015 at 06:44:58PM +1000, Alexey Kardashevskiy wrote: > This adds create/remove window ioctls to create and remove DMA windows. > sPAPR defines a Dynamic DMA windows capability which allows > para-virtualized guests to create additional DMA windows on a PCI bus. > The existing linux kernels use this new window to map the entire guest > memory and switch to the direct DMA operations saving time on map/unmap > requests which would normally happen in a big amounts. > > This adds 2 ioctl handlers - VFIO_IOMMU_SPAPR_TCE_CREATE and > VFIO_IOMMU_SPAPR_TCE_REMOVE - to create and remove windows. > Up to 2 windows are supported now by the hardware and by this driver. > > This changes VFIO_IOMMU_SPAPR_TCE_GET_INFO handler to return additional > information such as a number of supported windows and maximum number > levels of TCE tables. > > DDW is added as a capability, not as a SPAPR TCE IOMMU v2 unique feature > as we still want to support v2 on platforms which cannot do DDW for > the sake of TCE acceleration in KVM (coming soon). > > Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> > [aw: for the vfio related changes] > Acked-by: Alex Williamson <alex.william...@redhat.com>
Reviewed-by: David Gibson <da...@gibson.dropbear.id.au>
--
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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