On Mon, Jul 19, 2021 at 09:37:56PM -0700, Bart Van Assche wrote: > such that this object storage driver can be implemented as a user-space > library instead of as a kernel driver? As you may know vfio users can > either use eventfds for completion notifications or polling. An > interface like io_uring can be built easily on top of vfio. Yes. Similar to say the NVMe K/V command set this does not look like a candidate for a kernel driver.