Alex, here is a change to vaddr_get_pfn() that we discussed in this thread: https://lists.nongnu.org/archive/html/qemu-devel/2018-01/msg07117.html
Namely, drop support for passing Filesystem-DAX mappings through to guests. Perhaps in the future we can create some para-virtualized passthrough interface to coordinate guest-DMA vs host-filesystem operations. For now, this needs to be disabled for data-integrity and guaranteeing forward progress of filesystem operations.
If you want to take this through your tree please grab the other dax fixups as well. Otherwise, let me know and I'll take the lot through the nvdimm tree.
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Dan Williams (3): dax: fix S_DAX definition dax: short circuit vma_is_fsdax() in the CONFIG_FS_DAX=n case vfio: disable filesystem-dax page pinning
drivers/vfio/vfio_iommu_type1.c | 18 +++++++++++++++--- include/linux/fs.h | 4 +++- 2 files changed, 18 insertions(+), 4 deletions(-)