Alex, On 1/31/18 4:45 PM, Suravee Suthikulpanit wrote:
Currently, VFIO IOMMU type1 unmaps IOVA pages synchronously, which requires IOTLB flush for every IOVA unmap. This results in a large number of IOTLB flushes during initialization of pass-through devices. This can be avoided using the asynchronous (fast) IOTLB flush interface. Cc: Alex Williamson<alex.williamson@xxxxxxxxxx> Cc: Joerg Roedel<joro@xxxxxxxxxx> Signed-off-by: Suravee Suthikulpanit<suravee.suthikulpanit@xxxxxxx> --- Changes from v3 (https://lkml.org/lkml/2018/1/21/244) * Refactor the code to unmap_unpin_fast() and unmap_unpin_slow() to improve code readability. * Fix logic in vfio_unmap_unpin() to fallback to unmap_unpin_slow() only for the failing iova unmapping, and continue the next unmapping with the unmap_unpin_fast(). (per Alex) * Fix error handling in case of failing to do fast unmapping to warn only once. * Remove reference to GPU in the commit message.
Please ignore v4. I found an issue in error handling logic. Also, I need to change the return value back to size_t (as this was in a discussed in a separate thread). Sorry for confusion. I'll clean up and send out v5. Thanks, Suravee
