> From: Tian, Kevin <kevin.tian@xxxxxxxxx> > Sent: Wednesday, May 24, 2023 10:39 AM > > > From: Liu, Yi L <yi.l.liu@xxxxxxxxx> > > Sent: Wednesday, May 24, 2023 10:21 AM > > > > > > > > > > vfio_device_open_file() > > > > { > > > > dev_warn(device->dev, "vfio-noiommu device opened by user " > > > > "(%s:%d)\n", current->comm, task_pid_nr(current)); > > > > } > > > > > > There needs to be a taint when VFIO_GROUP is disabled. Thanks, > > I see. I misunderstood you. You are asking for a taint. 😊 > > > > Actually, I've considered it. But it appears to me the taint in > > vfio_group_find_or_alloc() is due to vfio allocates fake iommu_group. > > This seems to be a taint to kernel. But now, you are suggesting to add > > a taint as long as noiommu device is registered to vfio. Is it? If so, > > taint is required because the kernel is exposed to user DMA attack > due to lacking of IOMMU protection. > > fake iommu_group is just to meet vfio_group requirement. Got it. thanks. Regards, Yi Liu