On Sat, Apr 23, 2022 at 07:13:39PM +0800, zhangfei....@foxmail.com wrote: > > > On 5.17 > > > fops_release is called automatically, as well as iommu_sva_unbind_device. > > > On 5.18-rc1. > > > fops_release is not called, have to manually call close(fd) > > Right that's weird > Looks it is caused by the fix patch, via mmget, which may add refcount of > fd.
Yes indirectly I think: when the process mmaps the queue, mmap_region() takes a reference to the uacce fd. That reference is released either by explicit close() or munmap(), or by exit_mmap() (which is triggered by mmput()). Since there is an mm->fd dependency, we cannot add a fd->mm dependency, so no mmget()/mmput() in bind()/unbind(). I guess we should go back to refcounted PASIDs instead, to avoid freeing them until unbind(). Thanks, Jean _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
