On Wed, Jan 07, 2026 at 06:41:10PM -0800, Alex Mastro wrote: > On Wed, Jan 07, 2026 at 08:54:06PM -0400, Jason Gunthorpe wrote: > > On Wed, Jan 07, 2026 at 11:54:09PM +0000, David Matlack wrote: > > > On 2026-01-07 02:13 PM, Alex Mastro wrote: > > > > Test MMIO-backed DMA mappings by iommu_map()-ing mmap'ed BAR regions. > > > > > > Thanks for adding this! > > > > > > > Also update vfio_pci_bar_map() to align BAR mmaps for efficient huge > > > > page mappings. > > > > > > > > Only vfio_type1 variants are tested; iommufd variants can be added > > > > once kernel support lands. > > > > > > Are there plans to support mapping BARs via virtual address in iommufd? > > > I thought the plan was only to support via dma-bufs. Maybe Jason can > > > confirm. > > > > Only dmabuf. > > Ack. I got confused. I had thought iommufd's vfio container compatibility mode > was going to support this, but realized that doesn't make sense given past > discussions about the pitfalls of achieving these mappings the legacy way.
Oh, I was thinking about a compatability only flow only in the type 1 emulation that internally magically converts a VMA to a dmabuf, but I haven't written anything.. It is a bit tricky and the type 1 emulation has not been as popular as I expected?? Jason
