Re: [Qemu-devel] [PATCH V4 net-next] vhost_net: device IOTLB support

[Jason Wang <jasowang@redhat.com>]

On 2017年01月11日 12:32, Jason Wang wrote:
> This patches implements Device IOTLB support for vhost kernel. This is
> done through:
>
> 1) switch to use dma helpers when map/unmap vrings from vhost codes
> 2) introduce a set of VhostOps to:
>     - setting up device IOTLB request callback
>     - processing device IOTLB request
>     - processing device IOTLB invalidation
> 2) kernel support for Device IOTLB API:
>
> - allow vhost-net to query the IOMMU IOTLB entry through eventfd
> - enable the ability for qemu to update a specified mapping of vhost
> - through ioctl.
> - enable the ability to invalidate a specified range of iova for the
>    device IOTLB of vhost through ioctl. In x86/intel_iommu case this is
>    triggered through iommu memory region notifier from device IOTLB
>    invalidation descriptor processing routine.
>
> With all the above, kernel vhost_net can co-operate with userspace
> IOMMU. For vhost-user, the support could be easily done on top by
> implementing the VhostOps.
>
> Cc: Michael S. Tsirkin<mst@redhat.com>
> Signed-off-by: Jason Wang<jasowang@redhat.com>
> ---
> Changes from V4:
> - set iotlb callback only when IOMMU_PLATFORM is negotiated (fix
>    vhost-user qtest failure)
> - whitelist VIRTIO_F_IOMMU_PLATFORM instead of manually add it
> - keep cpu_physical_memory_map() in vhost_memory_map()
> ---

Note: the patch is for qemu not net-next :)