On Thu, Aug 05, 2021 at 11:07:22AM -0600, Alex Williamson wrote: > +void vfio_device_unmap_mapping_range(struct vfio_device *device, > + loff_t start, loff_t len) > +{ > + unmap_mapping_range(device->inode->i_mapping, start, len, true); (not a big deal, but still raise this up) It seems to me VFIO MMIO regions do not allow private maps, so even_cow==true should be the same with even_cow==false. even_cow==true will just check the page mapping for each pte even though they should just all match, imho, so logically "false" should work the same and should be tiny-little faster. Thanks, > +} > +EXPORT_SYMBOL_GPL(vfio_device_unmap_mapping_range); -- Peter Xu