Re: [PATCH 1/5] io_uring: prepare for extending io_uring with bpf

[Caleb Sander Mateos <csander@purestorage.com>]

On Tue, Nov 4, 2025 at 8:22 AM Ming Lei <ming.lei@redhat.com> wrote:
>
> Add one bpf operation & related framework and prepare for extending io_uring
> with bpf.
>
> Signed-off-by: Ming Lei <ming.lei@redhat.com>
> ---
>  include/uapi/linux/io_uring.h |  1 +
>  init/Kconfig                  |  7 +++++++
>  io_uring/Makefile             |  1 +
>  io_uring/bpf.c                | 26 ++++++++++++++++++++++++++
>  io_uring/opdef.c              | 10 ++++++++++
>  io_uring/uring_bpf.h          | 26 ++++++++++++++++++++++++++
>  6 files changed, 71 insertions(+)
>  create mode 100644 io_uring/bpf.c
>  create mode 100644 io_uring/uring_bpf.h
>
> diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
> index 04797a9b76bc..b167c1d4ce6e 100644
> --- a/include/uapi/linux/io_uring.h
> +++ b/include/uapi/linux/io_uring.h
> @@ -303,6 +303,7 @@ enum io_uring_op {
>         IORING_OP_PIPE,
>         IORING_OP_NOP128,
>         IORING_OP_URING_CMD128,
> +       IORING_OP_BPF,
>
>         /* this goes last, obviously */
>         IORING_OP_LAST,
> diff --git a/init/Kconfig b/init/Kconfig
> index cab3ad28ca49..14d566516643 100644
> --- a/init/Kconfig
> +++ b/init/Kconfig
> @@ -1843,6 +1843,13 @@ config IO_URING
>           applications to submit and complete IO through submission and
>           completion rings that are shared between the kernel and application.
>
> +config IO_URING_BPF
> +       bool "Enable IO uring bpf extension" if EXPERT
> +       depends on IO_URING && BPF
> +       help
> +         This option enables bpf extension for the io_uring interface, so
> +         application can define its own io_uring operation by bpf program.
> +
>  config GCOV_PROFILE_URING
>         bool "Enable GCOV profiling on the io_uring subsystem"
>         depends on IO_URING && GCOV_KERNEL
> diff --git a/io_uring/Makefile b/io_uring/Makefile
> index bc4e4a3fa0a5..35eeeaf64489 100644
> --- a/io_uring/Makefile
> +++ b/io_uring/Makefile
> @@ -22,3 +22,4 @@ obj-$(CONFIG_NET_RX_BUSY_POLL)        += napi.o
>  obj-$(CONFIG_NET) += net.o cmd_net.o
>  obj-$(CONFIG_PROC_FS) += fdinfo.o
>  obj-$(CONFIG_IO_URING_MOCK_FILE) += mock_file.o
> +obj-$(CONFIG_IO_URING_BPF)     += bpf.o
> diff --git a/io_uring/bpf.c b/io_uring/bpf.c
> new file mode 100644
> index 000000000000..8c47df13c7b5
> --- /dev/null
> +++ b/io_uring/bpf.c
> @@ -0,0 +1,26 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (c) 2024 Red Hat */
> +
> +#include <linux/kernel.h>
> +#include <linux/errno.h>
> +#include <uapi/linux/io_uring.h>
> +#include "io_uring.h"
> +#include "uring_bpf.h"
> +
> +int io_uring_bpf_issue(struct io_kiocb *req, unsigned int issue_flags)
> +{
> +       return -ECANCELED;
> +}
> +
> +int io_uring_bpf_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
> +{
> +       return -EOPNOTSUPP;
> +}
> +
> +void io_uring_bpf_fail(struct io_kiocb *req)
> +{
> +}
> +
> +void io_uring_bpf_cleanup(struct io_kiocb *req)
> +{
> +}
> diff --git a/io_uring/opdef.c b/io_uring/opdef.c
> index df52d760240e..d93ee3d577d4 100644
> --- a/io_uring/opdef.c
> +++ b/io_uring/opdef.c
> @@ -38,6 +38,7 @@
>  #include "futex.h"
>  #include "truncate.h"
>  #include "zcrx.h"
> +#include "uring_bpf.h"
>
>  static int io_no_issue(struct io_kiocb *req, unsigned int issue_flags)
>  {
> @@ -593,6 +594,10 @@ const struct io_issue_def io_issue_defs[] = {
>                 .prep                   = io_uring_cmd_prep,
>                 .issue                  = io_uring_cmd,
>         },
> +       [IORING_OP_BPF] = {
> +               .prep                   = io_uring_bpf_prep,
> +               .issue                  = io_uring_bpf_issue,

Should this set .prep = io_eopnotsupp_prep for !CONFIG_IO_URING_BPF
and remove the stub implementations? That would be more consistent
with the other opcodes when they are configured out, and ensure
io_uring_op_supported(IORING_OP_BPF) returns false for
!CONFIG_IO_URING_BPF.

Best,
Caleb


> +       },
>  };
>
>  const struct io_cold_def io_cold_defs[] = {
> @@ -851,6 +856,11 @@ const struct io_cold_def io_cold_defs[] = {
>                 .sqe_copy               = io_uring_cmd_sqe_copy,
>                 .cleanup                = io_uring_cmd_cleanup,
>         },
> +       [IORING_OP_BPF] = {
> +               .name                   = "BPF",
> +               .cleanup                = io_uring_bpf_cleanup,
> +               .fail                   = io_uring_bpf_fail,
> +       },
>  };
>
>  const char *io_uring_get_opcode(u8 opcode)
> diff --git a/io_uring/uring_bpf.h b/io_uring/uring_bpf.h
> new file mode 100644
> index 000000000000..bde774ce6ac0
> --- /dev/null
> +++ b/io_uring/uring_bpf.h
> @@ -0,0 +1,26 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#ifndef IOU_BPF_H
> +#define IOU_BPF_H
> +
> +#ifdef CONFIG_IO_URING_BPF
> +int io_uring_bpf_issue(struct io_kiocb *req, unsigned int issue_flags);
> +int io_uring_bpf_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
> +void io_uring_bpf_fail(struct io_kiocb *req);
> +void io_uring_bpf_cleanup(struct io_kiocb *req);
> +#else
> +static inline int io_uring_bpf_issue(struct io_kiocb *req, unsigned int issue_flags)
> +{
> +       return -ECANCELED;
> +}
> +static inline int io_uring_bpf_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
> +{
> +       return -EOPNOTSUPP;
> +}
> +static inline void io_uring_bpf_fail(struct io_kiocb *req)
> +{
> +}
> +static inline void io_uring_bpf_cleanup(struct io_kiocb *req)
> +{
> +}
> +#endif
> +#endif
> --
> 2.47.0
>