Re: [PATCH v3 0/4] io_uring/uring_cmd: allow non-iopoll cmds with IORING_SETUP_IOPOLL

[Ming Lei]

On Thu, Feb 19, 2026 at 10:22:23AM -0700, Caleb Sander Mateos wrote:
> Currently, creating an io_uring with IORING_SETUP_IOPOLL requires all
> requests issued to it to support iopoll. This prevents, for example,
> using ublk zero-copy together with IORING_SETUP_IOPOLL, as ublk
> zero-copy buffer registrations are performed using a uring_cmd. There's
> no technical reason why these non-iopoll uring_cmds can't be supported.
> They will either complete synchronously or via an external mechanism
> that calls io_uring_cmd_done(), so they don't need to be polled.

For sync uring command, it is fine to support for IOPOLL.

However, there are async uring command, which may be completed in irq
context, or in multishot way, at least the later isn't supported in
io_do_iopoll() yet.


Thanks, 
Ming