On Mon, Oct 27, 2025 at 02:21:56PM -0700, Mukesh R wrote: > Hi Alex, > > This regards vfio passthru support on hyperv running linux as dom0 aka > root. At a high level, cloud hypervisor uses vfio for set up as usual, > then maps the mmio ranges via the hyperv linux driver ioctls. > > Over a year ago, when working on this I had used vm_pgoff to get the pfn > for the mmio, that was 5.15 and early 6.x kernels. Now that I am porting > to 6.18 for upstreaming, I noticed: > > commit aac6db75a9fc > Author: Alex Williamson <[email protected]> > vfio/pci: Use unmap_mapping_range() > > changed the behavior and vm_pgoff is no longer holding the pfn. In light > of that, I wondered if the following minor change, making vma_to_pfn() > public (after renaming it), would be acceptable to you.
No way, no driver should be looking into VMAs like this - it is already a known security problem. Is this "hyperv linux driver ioctls" upstream? You should probably be looking to use the coming DMABUF stuff instead. Jason
