search for: vfio_iommu_dma_map

...hardware. However, as soon as the host kernel has picked a region, host userspace needs to know that it can no longer use addresses in that region for DMA-able guest memory. It's a lot easier when the address is fixed in hardware and the host userspace will never be stupid enough to try and VFIO_IOMMU_DMA_MAP it, but in the more general case where MSI writes undergo IOMMU address translation so it's an arbitrary IOVA, this has the potential to conflict with stuff like guest memory hotplug. What we currently have is just the simplest option, with the host kernel just picking something up-front a...

> From: Jean-Philippe Brucker [mailto:jean-philippe.brucker at arm.com] > Sent: Wednesday, February 14, 2018 10:54 PM > > The virtio IOMMU is a para-virtualized device, allowing to send IOMMU > requests such as map/unmap over virtio-mmio transport without > emulating > page tables. This implementation handles ATTACH, DETACH, MAP and > UNMAP > requests. > > The

> From: Jean-Philippe Brucker [mailto:jean-philippe.brucker at arm.com] > Sent: Wednesday, February 14, 2018 10:54 PM > > The virtio IOMMU is a para-virtualized device, allowing to send IOMMU > requests such as map/unmap over virtio-mmio transport without > emulating > page tables. This implementation handles ATTACH, DETACH, MAP and > UNMAP > requests. > > The

...st > > kernel has picked a region, host userspace needs to know that it can no > > longer use addresses in that region for DMA-able guest memory. It's a > > lot easier when the address is fixed in hardware and the host userspace > > will never be stupid enough to try and VFIO_IOMMU_DMA_MAP it, but in > > the > > more general case where MSI writes undergo IOMMU address translation > > so > > it's an arbitrary IOVA, this has the potential to conflict with stuff > > like guest memory hotplug. > > > > What we currently have is just the simple...