On Fri, Feb 27, 2026 at 01:52:15PM -0800, Alex Mastro wrote:
On Fri, Feb 27, 2026 at 03:48:07PM -0400, Jason Gunthorpe wrote:
I actually would like to go the other way and have VFIO always have a DMABUF under the VMA's it mmaps because that will make it easy to finish the type1 emulation which requires finding dmabufs for the VMAs.
This is a still better idea since it avoid duplicating the VMA flow into two parts..
I suppose this would also compose with your idea to use dma-buf for iommufd_compat support of VFIO_IOMMU_MAP_DMA of vfio device fd-backed mmap()s [1]? Instead of needing to materialize a new dma-buf, you could use the existing backing one?
[1] https://lore.kernel.org/all/20260108141044.GC545276@ziepe.ca/
Sorry, I can't read. That's literally what you said!