linux/io_uring/bpf-ops.c, branch master

io_uring: unify getting ctx from passed in file descriptor

2026-04-08T19:21:35Z

io_uring_enter() and io_uring_register() end up having duplicated code for getting a ctx from a passed in file descriptor, for either a registered ring descriptor or a normal file descriptor. Move the io_uring_register_get_file() into io_uring.c and name it a bit more generically, and use it from both callsites rather than have that logic and handling duplicated. Signed-off-by: Jens Axboe

io_uring/bpf-ops: implement bpf ops registration

2026-03-16T22:15:00Z

Implement BPF struct ops registration. It's registered off the BPF path, and can be removed by BPF as well as io_uring. To protect it, introduce a global lock synchronising registration. ctx->uring_lock can be nested under it. ctx->bpf_ops is write protected by both locks and so it's safe to read it under either of them. Signed-off-by: Pavel Begunkov Link: https://patch.msgid.link/1f46bffd76008de49cbafa2ad77d348810a4f69e.1772109579.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring/bpf-ops: add kfunc helpers

2026-03-16T22:15:00Z

Add two kfuncs that should cover most of the needs: 1. bpf_io_uring_submit_sqes(), which allows to submit io_uring requests. It mirrors the normal user space submission path and follows all related io_uring_enter(2) rules. i.e. SQEs are taken from the SQ according to head/tail values. In case of IORING_SETUP_SQ_REWIND, it'll submit first N entries. 2. bpf_io_uring_get_region() returns a pointer to the specified region, where io_uring regions are kernel-userspace shared chunks of memory. It takes the size as an argument, which should be a load time constant. There are 3 types of regions: - IOU_REGION_SQ returns the submission queue. - IOU_REGION_CQ stores the CQ, SQ/CQ headers and the sqarray. In other words, it gives same memory that would normally be mmap'ed with IORING_FEAT_SINGLE_MMAP enabled IORING_OFF_SQ_RING. - IOU_REGION_MEM represents the memory / parameter region. It can be used to store request indirect parameters and for kernel - user communication. It intentionally provides a thin but flexible API and expects BPF programs to implement CQ/SQ header parsing, CQ walking, etc. That mirrors how the normal user space works with rings and should help to minimise kernel / kfunc helpers changes while introducing new generic io_uring features. Signed-off-by: Pavel Begunkov Link: https://patch.msgid.link/967bcc10e94c796eb273998621551b2a21848cde.1772109579.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring/bpf-ops: implement loop_step with BPF struct_ops

2026-03-16T22:15:00Z

Introduce io_uring BPF struct ops implementing the loop_step callback, which will allow BPF to overwrite the default io_uring event loop logic. The callback takes an io_uring context, the main role of which is to be passed to io_uring kfuncs. The other argument is a struct iou_loop_params, which BPF can use to request CQ waiting and communicate other parameters. See the event loop description in the previous patch for more details. Signed-off-by: Pavel Begunkov Link: https://patch.msgid.link/98db437651ce64e9cbeb611c60bf5887259db09f.1772109579.git.asml.silence@gmail.com Signed-off-by: Jens Axboe