> From: Liu, Yi L <yi.l.liu@xxxxxxxxx> > Sent: Wednesday, April 5, 2023 3:55 PM > > > > Therefore, I think as written, the singleton dev_set hot-reset is > > enabled for iommufd and (unintentionally?) for the group path, while > > also negating a requirement for a group fd or that a provided group fd > > actually matches the device in this latter case. The null-array > > approach is not however extended to groups for more general use. > > Additionally, limiting no-iommu hot-reset to singleton dev_sets > > provides only a marginal functional difference vs VFIO_DEVICE_RESET. > > I think the singletion dev_set hot-reset is for iommufd (or more accurately > for the noiommu case in cdev path). but actually, singleton dev_set hot-reset can work for group path as well. Based on this, I'm also wondering do we really want to have singleton dev_set hot-reset only for cdev noiommu case? or we allow it generally or just don't support it as it is equivalent with VFIO_DEVICE_RESET? If we don't support singletion dev_set hot-reset, noiommu devices in cdev path shall fail the hot-reset if empty-fd array is provided. But we may just document that empty-fd array does not work for noiommu. User should use the device fd array. Regards, Yi Liu