On Tue, Dec 06, 2022 at 01:55:45PM -0800, Steve Sistare wrote: > Lastly, if a task exits or execs, and it still owns any dma mappings, they > are unmapped and unpinned. This guarantees that pages do not remain pinned > indefinitely if a vfio descriptor is leaked to another process, and requires > tasks to explicitly transfer ownership of dma (and hence locked_vm) to a new > task and mm when continued operation is desired. The vfio driver maps a > special vma so it can detect exit and exec, via the vm_operations_struct > close callback. I don't think any of this is necessary. If a VFIO FD is "leaked" to another process there are many hostile things that process can do beyond invoke this new ioctl. Considering the complexity I prefer to drop this. Jason
