On Wed, Jun 04, 2025 at 09:37:47AM -0300, Jason Gunthorpe wrote: > On Wed, Jun 04, 2025 at 11:47:14AM +1000, Alexey Kardashevskiy wrote: > > > If it is the case of killing QEMU - then there is no usespace and > > then it is a matter of what fd is closed first - VFIO-PCI or > > IOMMUFD, we could teach IOMMUFD to hold an VFIO-PCI fd to guarantee > > the order. Thanks, > > It is the other way around VFIO holds the iommufd and it always > destroys first. > > We are missing a bit where the vfio destruction of the idevice does > not clean up the vdevice too. Seems there is still problem, the suggested flow is: 1. VFIO fops release 2. vfio_pci_core_close_device() 3. vfio_df_iommufd_unbind() 4. iommufd_device_unbind() 5. iommufd_device_destroy() 6. iommufd_vdevice_destroy() (not implemented) 7. iommufd_vdevice_tsm_unbind() In step 2, vfio pci does all cleanup, including invalidate MMIO. In step 7 vdevice does tsm unbind, this is not correct. TSM unbind should be done before invalidating MMIO. TSM unbind should always the first thing to do to release lockdown, then cleanup physical device configuration. Thanks, Yilun > > Jason
