[RFC PATCH v1 00/18] Provide a new two step DMA API mapping API

[Christoph Hellwig]

I just tried to boot this on my usual qemu test setup with emulated
nvme devices, and it dead-loops with messages like this fairly late
in the boot cycle:

[   43.826627] iommu: unaligned: iova 0xfff7e000 pa 0x000000010be33650 size 0x1000 min_pagesz 0x1000
[   43.826982] dma_mapping_error -12

passing intel_iommu=off instead of intel_iommu=on (expectedly) makes
it go away.