drivers/nvme/host/ioctl.c | 4 ---- include/linux/io_uring_types.h | 3 +++ io_uring/io_uring.c | 19 ++++++------------- io_uring/opdef.c | 10 ---------- io_uring/opdef.h | 2 -- io_uring/rw.c | 11 ++++++----- io_uring/uring_cmd.c | 9 ++++----- 7 files changed, 19 insertions(+), 39 deletions(-)
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(), io_uring_cmd_post_mshot_cqe32(), or io_uring_mshot_cmd_post_cqe(), so they don't need to be polled. Allow uring_cmd requests to be issued to IORING_SETUP_IOPOLL io_urings even if their files don't implement ->uring_cmd_iopoll(). Use a new REQ_F_IOPOLL flag to track whether a request is using iopoll. This makes the iopoll_queue opcode definition flag unnecessary. The last commit removes an unnecessary IO_URING_F_IOPOLL check in nvme_dev_uring_cmd() as NVMe admin passthru commands can be issued to IORING_SETUP_IOPOLL io_urings now. v5: perform one iteration of iopoll when min_events == 0 (Claude) v4: check non-iopoll CQEs against min_events in io_iopoll_check() (Ming) v3: fix REW -> REQ typo (Anuj) v2: - Add REQ_F_IOPOLL request flag, remove redundant iopoll_queue - Split IORING_OP_URING_CMD128 fix to a separate commit Caleb Sander Mateos (5): io_uring: add REQ_F_IOPOLL io_uring: remove iopoll_queue from struct io_issue_def io_uring: count CQEs in io_iopoll_check() io_uring/uring_cmd: allow non-iopoll cmds with IORING_SETUP_IOPOLL nvme: remove nvme_dev_uring_cmd() IO_URING_F_IOPOLL check drivers/nvme/host/ioctl.c | 4 ---- include/linux/io_uring_types.h | 3 +++ io_uring/io_uring.c | 19 ++++++------------- io_uring/opdef.c | 10 ---------- io_uring/opdef.h | 2 -- io_uring/rw.c | 11 ++++++----- io_uring/uring_cmd.c | 9 ++++----- 7 files changed, 19 insertions(+), 39 deletions(-) -- 2.45.2
On Mon, 02 Mar 2026 10:29:09 -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(), io_uring_cmd_post_mshot_cqe32(), or
> io_uring_mshot_cmd_post_cqe(), so they don't need to be polled.
>
> [...]
Applied, thanks!
[1/5] io_uring: add REQ_F_IOPOLL
commit: 9165dc4fa969b64c2d4396ee4e1546a719978dd1
[2/5] io_uring: remove iopoll_queue from struct io_issue_def
commit: 7995be40deb3ab8b5df7bdf0621f33aa546aefa7
[3/5] io_uring: count CQEs in io_iopoll_check()
commit: 3a5e96d47f7ea37fb6adf37882eec1521f8ca75e
[4/5] io_uring/uring_cmd: allow non-iopoll cmds with IORING_SETUP_IOPOLL
commit: 23475637b0c47e5028817c9fd4dabe8f7409ca6c
[5/5] nvme: remove nvme_dev_uring_cmd() IO_URING_F_IOPOLL check
commit: f144dbac4b177cfd026e417ab98da518ff3372cb
Best regards,
--
Jens Axboe
On 3/16/26 4:14 PM, Jens Axboe wrote: > > On Mon, 02 Mar 2026 10:29:09 -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(), io_uring_cmd_post_mshot_cqe32(), or >> io_uring_mshot_cmd_post_cqe(), so they don't need to be polled. >> >> [...] > > Applied, thanks! > > [1/5] io_uring: add REQ_F_IOPOLL > commit: 9165dc4fa969b64c2d4396ee4e1546a719978dd1 > [2/5] io_uring: remove iopoll_queue from struct io_issue_def > commit: 7995be40deb3ab8b5df7bdf0621f33aa546aefa7 > [3/5] io_uring: count CQEs in io_iopoll_check() > commit: 3a5e96d47f7ea37fb6adf37882eec1521f8ca75e > [4/5] io_uring/uring_cmd: allow non-iopoll cmds with IORING_SETUP_IOPOLL > commit: 23475637b0c47e5028817c9fd4dabe8f7409ca6c > [5/5] nvme: remove nvme_dev_uring_cmd() IO_URING_F_IOPOLL check > commit: f144dbac4b177cfd026e417ab98da518ff3372cb Caleb, want to send the liburing tests and documentation updates too? -- Jens Axboe
On Mon, Mar 16, 2026 at 6:01 PM Jens Axboe <axboe@kernel.dk> wrote: > > On 3/16/26 4:14 PM, Jens Axboe wrote: > > > > On Mon, 02 Mar 2026 10:29:09 -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(), io_uring_cmd_post_mshot_cqe32(), or > >> io_uring_mshot_cmd_post_cqe(), so they don't need to be polled. > >> > >> [...] > > > > Applied, thanks! > > > > [1/5] io_uring: add REQ_F_IOPOLL > > commit: 9165dc4fa969b64c2d4396ee4e1546a719978dd1 > > [2/5] io_uring: remove iopoll_queue from struct io_issue_def > > commit: 7995be40deb3ab8b5df7bdf0621f33aa546aefa7 > > [3/5] io_uring: count CQEs in io_iopoll_check() > > commit: 3a5e96d47f7ea37fb6adf37882eec1521f8ca75e > > [4/5] io_uring/uring_cmd: allow non-iopoll cmds with IORING_SETUP_IOPOLL > > commit: 23475637b0c47e5028817c9fd4dabe8f7409ca6c > > [5/5] nvme: remove nvme_dev_uring_cmd() IO_URING_F_IOPOLL check > > commit: f144dbac4b177cfd026e417ab98da518ff3372cb > > Caleb, want to send the liburing tests and documentation updates too? Sure. What type of file do you recommend using for non-iopoll uring_cmds? Most of them seem to have relatively specific hardware (e.g. blkdev_uring_cmd, nvme_dev_uring_cmd) or kernel configuration (e.g. ublk_ch_uring_cmd, io_mock_cmd) requirements, as well as requiring elevated permissions. Maybe io_uring_cmd_sock would be the most general? Best, Caleb
On 3/17/26 6:47 PM, Caleb Sander Mateos wrote: > On Mon, Mar 16, 2026 at 6:01 PM Jens Axboe <axboe@kernel.dk> wrote: >> >> On 3/16/26 4:14 PM, Jens Axboe wrote: >>> >>> On Mon, 02 Mar 2026 10:29:09 -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(), io_uring_cmd_post_mshot_cqe32(), or >>>> io_uring_mshot_cmd_post_cqe(), so they don't need to be polled. >>>> >>>> [...] >>> >>> Applied, thanks! >>> >>> [1/5] io_uring: add REQ_F_IOPOLL >>> commit: 9165dc4fa969b64c2d4396ee4e1546a719978dd1 >>> [2/5] io_uring: remove iopoll_queue from struct io_issue_def >>> commit: 7995be40deb3ab8b5df7bdf0621f33aa546aefa7 >>> [3/5] io_uring: count CQEs in io_iopoll_check() >>> commit: 3a5e96d47f7ea37fb6adf37882eec1521f8ca75e >>> [4/5] io_uring/uring_cmd: allow non-iopoll cmds with IORING_SETUP_IOPOLL >>> commit: 23475637b0c47e5028817c9fd4dabe8f7409ca6c >>> [5/5] nvme: remove nvme_dev_uring_cmd() IO_URING_F_IOPOLL check >>> commit: f144dbac4b177cfd026e417ab98da518ff3372cb >> >> Caleb, want to send the liburing tests and documentation updates too? > > Sure. What type of file do you recommend using for non-iopoll > uring_cmds? Most of them seem to have relatively specific hardware > (e.g. blkdev_uring_cmd, nvme_dev_uring_cmd) or kernel configuration > (e.g. ublk_ch_uring_cmd, io_mock_cmd) requirements, as well as > requiring elevated permissions. Maybe io_uring_cmd_sock would be the > most general? Yep I think uring_cmd sock commands would be a good choice. Bonus points if you write the test as such that we can easily plug in future commands we allow with IOPOLL as well, as I would imagine we'd expand which we allow going forward once vetted. -- Jens Axboe
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