> From: Tian, Kevin <[email protected]> > Sent: Tuesday, February 7, 2023 2:25 PM > > > From: Liu, Yi L <[email protected]> > > Sent: Monday, February 6, 2023 5:05 PM > > > > struct vfio_device_file * > > -vfio_allocate_device_file(struct vfio_device *device) > > +vfio_allocate_device_file(struct vfio_device *device, bool > is_cdev_device) > > { > > struct vfio_device_file *df; > > > > @@ -407,6 +407,7 @@ vfio_allocate_device_file(struct vfio_device > *device) > > return ERR_PTR(-ENOMEM); > > > > df->device = device; > > + df->is_cdev_device = is_cdev_device; > > You missed Alex's comment that the one caller can open code the > assignment instead of introducing an unmemorable Boolean arg here.
Oh, yes. will open code to set it in cdev path. > > > > + /* > > + * Device cdev path cannot support multiple device open since > > + * it doesn't have a secure way for it. So a second device > > + * open attempt should be failed if the caller is from a cdev > > + * path or the device has already been opened by a cdev path. > > + */ > > + if (device->open_count != 0 && > > + (df->is_cdev_device || device->single_open)) > > + return -EINVAL; > > + > > If we are gonna handle the exclusive open via dma ownership, then > here we don't need a new single_open flag inside vfio_device since > only one interface (cdev or group) could be used to open this device. > > Just preventing multi-open in cdev is sufficient here. I see. Per below discussion, just need to make group path always use vfio_group pointer as DMA marker. https://lore.kernel.org/kvm/bn9pr11mb5276fa68e8cad6394a8887848c...@bn9pr11mb5276.namprd11.prod.outlook.com/ Regards, Yi Liu
