From: Ming Lei <ming.lei@redhat.com>
To: Pavel Begunkov <asml.silence@gmail.com>
Cc: io-uring@vger.kernel.org, axboe@kernel.dk,
Martin KaFai Lau <martin.lau@linux.dev>,
bpf@vger.kernel.org,
Alexei Starovoitov <alexei.starovoitov@gmail.com>,
Andrii Nakryiko <andrii@kernel.org>
Subject: Re: [PATCH v3 10/10] selftests/io_uring: add bpf io_uring selftests
Date: Fri, 14 Nov 2025 21:08:52 +0800 [thread overview]
Message-ID: <aRcp5Gi41i-g64ov@fedora> (raw)
In-Reply-To: <6143e4393c645c539fc34dc37eeb6d682ad073b9.1763031077.git.asml.silence@gmail.com>
On Thu, Nov 13, 2025 at 11:59:47AM +0000, Pavel Begunkov wrote:
> Add a io_uring bpf selftest/example. runner.c sets up a ring and BPF and
> calls io_uring_enter syscall to run the BPF program. All the execution
> logic is in basic.bpf.c, which creates a request, waits for its
> completion and repeats it N=10 times, after which it terminates. The
> makefile is borrowed from sched_ext.
>
> Note, it doesn't need to be all in BPF and can be intermingled with
> userspace code. This needs a separate example.
>
> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
> ---
> tools/testing/selftests/Makefile | 3 +-
> tools/testing/selftests/io_uring/Makefile | 164 +++++++++++++++++++
> tools/testing/selftests/io_uring/basic.bpf.c | 81 +++++++++
> tools/testing/selftests/io_uring/common.h | 2 +
> tools/testing/selftests/io_uring/runner.c | 80 +++++++++
> tools/testing/selftests/io_uring/types.bpf.h | 136 +++++++++++++++
> 6 files changed, 465 insertions(+), 1 deletion(-)
> create mode 100644 tools/testing/selftests/io_uring/Makefile
> create mode 100644 tools/testing/selftests/io_uring/basic.bpf.c
> create mode 100644 tools/testing/selftests/io_uring/common.h
> create mode 100644 tools/testing/selftests/io_uring/runner.c
> create mode 100644 tools/testing/selftests/io_uring/types.bpf.h
>
> diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
> index c46ebdb9b8ef..31dd369a7154 100644
> --- a/tools/testing/selftests/Makefile
> +++ b/tools/testing/selftests/Makefile
> @@ -129,6 +129,7 @@ TARGETS += vfio
> TARGETS += x86
> TARGETS += x86/bugs
> TARGETS += zram
> +TARGETS += io_uring
> #Please keep the TARGETS list alphabetically sorted
> # Run "make quicktest=1 run_tests" or
> # "make quicktest=1 kselftest" from top level Makefile
> @@ -146,7 +147,7 @@ endif
> # User can optionally provide a TARGETS skiplist. By default we skip
> # targets using BPF since it has cutting edge build time dependencies
> # which require more effort to install.
> -SKIP_TARGETS ?= bpf sched_ext
> +SKIP_TARGETS ?= bpf sched_ext io_uring
> ifneq ($(SKIP_TARGETS),)
> TMP := $(filter-out $(SKIP_TARGETS), $(TARGETS))
> override TARGETS := $(TMP)
> diff --git a/tools/testing/selftests/io_uring/Makefile b/tools/testing/selftests/io_uring/Makefile
> new file mode 100644
> index 000000000000..7dfba422e5a6
> --- /dev/null
> +++ b/tools/testing/selftests/io_uring/Makefile
> @@ -0,0 +1,164 @@
> +# SPDX-License-Identifier: GPL-2.0
> +include ../../../build/Build.include
> +include ../../../scripts/Makefile.arch
> +include ../../../scripts/Makefile.include
> +
> +TEST_GEN_PROGS := runner
> +
> +# override lib.mk's default rules
> +OVERRIDE_TARGETS := 1
> +include ../lib.mk
> +
> +CURDIR := $(abspath .)
> +REPOROOT := $(abspath ../../../..)
> +TOOLSDIR := $(REPOROOT)/tools
> +LIBDIR := $(TOOLSDIR)/lib
> +BPFDIR := $(LIBDIR)/bpf
> +TOOLSINCDIR := $(TOOLSDIR)/include
> +BPFTOOLDIR := $(TOOLSDIR)/bpf/bpftool
> +APIDIR := $(TOOLSINCDIR)/uapi
> +GENDIR := $(REPOROOT)/include/generated
> +GENHDR := $(GENDIR)/autoconf.h
> +
> +OUTPUT_DIR := $(OUTPUT)/build
> +OBJ_DIR := $(OUTPUT_DIR)/obj
> +INCLUDE_DIR := $(OUTPUT_DIR)/include
> +BPFOBJ_DIR := $(OBJ_DIR)/libbpf
> +IOUOBJ_DIR := $(OBJ_DIR)/io_uring
> +LIBBPF_OUTPUT := $(OBJ_DIR)/libbpf/libbpf.a
> +BPFOBJ := $(BPFOBJ_DIR)/libbpf.a
> +
> +DEFAULT_BPFTOOL := $(OUTPUT_DIR)/host/sbin/bpftool
> +HOST_OBJ_DIR := $(OBJ_DIR)/host/bpftool
> +HOST_LIBBPF_OUTPUT := $(OBJ_DIR)/host/libbpf/
> +HOST_LIBBPF_DESTDIR := $(OUTPUT_DIR)/host/
> +HOST_DESTDIR := $(OUTPUT_DIR)/host/
> +
> +VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux) \
> + $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux) \
> + ../../../../vmlinux \
> + /sys/kernel/btf/vmlinux \
> + /boot/vmlinux-$(shell uname -r)
> +VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
> +ifeq ($(VMLINUX_BTF),)
> +$(error Cannot find a vmlinux for VMLINUX_BTF at any of "$(VMLINUX_BTF_PATHS)")
> +endif
> +
> +BPFTOOL ?= $(DEFAULT_BPFTOOL)
> +
> +ifneq ($(wildcard $(GENHDR)),)
> + GENFLAGS := -DHAVE_GENHDR
> +endif
> +
> +CFLAGS += -g -O2 -rdynamic -pthread -Wall -Werror $(GENFLAGS) \
> + -I$(INCLUDE_DIR) -I$(GENDIR) -I$(LIBDIR) \
> + -I$(TOOLSINCDIR) -I$(APIDIR) -I$(CURDIR)/include
> +
> +# Silence some warnings when compiled with clang
> +ifneq ($(LLVM),)
> +CFLAGS += -Wno-unused-command-line-argument
> +endif
> +
> +LDFLAGS = -lelf -lz -lpthread -lzstd
> +
> +IS_LITTLE_ENDIAN = $(shell $(CC) -dM -E - </dev/null | \
> + grep 'define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__')
> +
> +# Get Clang's default includes on this system, as opposed to those seen by
> +# '-target bpf'. This fixes "missing" files on some architectures/distros,
> +# such as asm/byteorder.h, asm/socket.h, asm/sockios.h, sys/cdefs.h etc.
> +#
> +# Use '-idirafter': Don't interfere with include mechanics except where the
> +# build would have failed anyways.
> +define get_sys_includes
> +$(shell $(1) $(2) -v -E - </dev/null 2>&1 \
> + | sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') \
> +$(shell $(1) $(2) -dM -E - </dev/null | grep '__riscv_xlen ' | awk '{printf("-D__riscv_xlen=%d -D__BITS_PER_LONG=%d", $$3, $$3)}')
> +endef
> +
> +ifneq ($(CROSS_COMPILE),)
> +CLANG_TARGET_ARCH = --target=$(notdir $(CROSS_COMPILE:%-=%))
> +endif
> +
> +CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH))
> +
> +BPF_CFLAGS = -g -D__TARGET_ARCH_$(SRCARCH) \
> + $(if $(IS_LITTLE_ENDIAN),-mlittle-endian,-mbig-endian) \
> + -I$(CURDIR)/include -I$(CURDIR)/include/bpf-compat \
> + -I$(INCLUDE_DIR) -I$(APIDIR) \
> + -I$(REPOROOT)/include \
> + $(CLANG_SYS_INCLUDES) \
> + -Wall -Wno-compare-distinct-pointer-types \
> + -Wno-incompatible-function-pointer-types \
> + -O2 -mcpu=v3
> +
> +# sort removes libbpf duplicates when not cross-building
> +MAKE_DIRS := $(sort $(OBJ_DIR)/libbpf $(OBJ_DIR)/libbpf \
> + $(OBJ_DIR)/bpftool $(OBJ_DIR)/resolve_btfids \
> + $(HOST_OBJ_DIR) $(INCLUDE_DIR) $(IOUOBJ_DIR))
> +
> +$(MAKE_DIRS):
> + $(call msg,MKDIR,,$@)
> + $(Q)mkdir -p $@
> +
> +$(BPFOBJ): $(wildcard $(BPFDIR)/*.[ch] $(BPFDIR)/Makefile) \
> + $(APIDIR)/linux/bpf.h \
> + | $(OBJ_DIR)/libbpf
> + $(Q)$(MAKE) $(submake_extras) -C $(BPFDIR) OUTPUT=$(OBJ_DIR)/libbpf/ \
> + ARCH=$(ARCH) CC="$(CC)" CROSS_COMPILE=$(CROSS_COMPILE) \
> + EXTRA_CFLAGS='-g -O0 -fPIC' \
> + DESTDIR=$(OUTPUT_DIR) prefix= all install_headers
> +
> +$(DEFAULT_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) \
> + $(LIBBPF_OUTPUT) | $(HOST_OBJ_DIR)
> + $(Q)$(MAKE) $(submake_extras) -C $(BPFTOOLDIR) \
> + ARCH= CROSS_COMPILE= CC=$(HOSTCC) LD=$(HOSTLD) \
> + EXTRA_CFLAGS='-g -O0' \
> + OUTPUT=$(HOST_OBJ_DIR)/ \
> + LIBBPF_OUTPUT=$(HOST_LIBBPF_OUTPUT) \
> + LIBBPF_DESTDIR=$(HOST_LIBBPF_DESTDIR) \
> + prefix= DESTDIR=$(HOST_DESTDIR) install-bin
> +
> +$(INCLUDE_DIR)/vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL) | $(INCLUDE_DIR)
> +ifeq ($(VMLINUX_H),)
> + $(call msg,GEN,,$@)
> + $(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF) format c > $@
> +else
> + $(call msg,CP,,$@)
> + $(Q)cp "$(VMLINUX_H)" $@
> +endif
> +
> +$(IOUOBJ_DIR)/%.bpf.o: %.bpf.c $(INCLUDE_DIR)/vmlinux.h | $(BPFOBJ) $(IOUOBJ_DIR)
> + $(call msg,CLNG-BPF,,$(notdir $@))
> + $(Q)$(CLANG) $(BPF_CFLAGS) -target bpf -c $< -o $@
> +
> +$(INCLUDE_DIR)/%.bpf.skel.h: $(IOUOBJ_DIR)/%.bpf.o $(INCLUDE_DIR)/vmlinux.h $(BPFTOOL) | $(INCLUDE_DIR)
> + $(eval sched=$(notdir $@))
> + $(call msg,GEN-SKEL,,$(sched))
> + $(Q)$(BPFTOOL) gen object $(<:.o=.linked1.o) $<
> + $(Q)$(BPFTOOL) gen object $(<:.o=.linked2.o) $(<:.o=.linked1.o)
> + $(Q)$(BPFTOOL) gen object $(<:.o=.linked3.o) $(<:.o=.linked2.o)
> + $(Q)diff $(<:.o=.linked2.o) $(<:.o=.linked3.o)
> + $(Q)$(BPFTOOL) gen skeleton $(<:.o=.linked3.o) name $(subst .bpf.skel.h,,$(sched)) > $@
> + $(Q)$(BPFTOOL) gen subskeleton $(<:.o=.linked3.o) name $(subst .bpf.skel.h,,$(sched)) > $(@:.skel.h=.subskel.h)
> +
> +override define CLEAN
> + rm -rf $(OUTPUT_DIR)
> + rm -f $(TEST_GEN_PROGS)
> +endef
> +
> +all_test_bpfprogs := $(foreach prog,$(wildcard *.bpf.c),$(INCLUDE_DIR)/$(patsubst %.c,%.skel.h,$(prog)))
> +
> +$(IOUOBJ_DIR)/runner.o: runner.c $(all_test_bpfprogs) | $(IOUOBJ_DIR) $(BPFOBJ)
> + $(CC) $(CFLAGS) -c $< -o $@
> +
> +$(OUTPUT)/runner: $(IOUOBJ_DIR)/runner.o $(BPFOBJ)
> + @echo "$(testcase-targets)"
> + echo 111
> + $(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS)
> +
> +.DEFAULT_GOAL := all
> +
> +.DELETE_ON_ERROR:
> +
> +.SECONDARY:
> diff --git a/tools/testing/selftests/io_uring/basic.bpf.c b/tools/testing/selftests/io_uring/basic.bpf.c
> new file mode 100644
> index 000000000000..c7954146ae4d
> --- /dev/null
> +++ b/tools/testing/selftests/io_uring/basic.bpf.c
> @@ -0,0 +1,81 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#include <linux/types.h>
> +#include <linux/stddef.h>
> +#include <bpf/bpf_helpers.h>
> +#include <bpf/bpf_tracing.h>
> +#include "types.bpf.h"
> +#include "common.h"
> +
> +extern int bpf_io_uring_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr) __ksym;
> +extern __u8 *bpf_io_uring_get_region(struct io_ring_ctx *ctx, __u32 region_id,
> + const __u64 rdwr_buf_size) __ksym;
> +
> +static inline void io_bpf_wait_nr(struct io_ring_ctx *ring,
> + struct iou_loop_state *ls, int nr)
> +{
> + ls->cq_tail = ring->rings->cq.head + nr;
> +}
> +
> +enum {
> + RINGS_REGION_ID = 0,
> + SQ_REGION_ID = 1,
> +};
> +
> +char LICENSE[] SEC("license") = "Dual BSD/GPL";
> +int reqs_to_run;
> +
> +SEC("struct_ops.s/link_loop")
> +int BPF_PROG(link_loop, struct io_ring_ctx *ring, struct iou_loop_state *ls)
> +{
> + struct ring_hdr *sq_hdr, *cq_hdr;
> + struct io_uring_cqe *cqe, *cqes;
> + struct io_uring_sqe *sqes, *sqe;
> + void *rings;
> + int ret;
> +
> + sqes = (void *)bpf_io_uring_get_region(ring, SQ_REGION_ID,
> + SQ_ENTRIES * sizeof(struct io_uring_sqe));
> + rings = (void *)bpf_io_uring_get_region(ring, RINGS_REGION_ID,
> + 64 + CQ_ENTRIES * sizeof(struct io_uring_cqe));
> + if (!rings || !sqes) {
> + bpf_printk("error: can't get regions");
> + return IOU_LOOP_STOP;
> + }
> +
> + sq_hdr = rings;
> + cq_hdr = sq_hdr + 1;
> + cqes = rings + 64;
> +
> + if (cq_hdr->tail != cq_hdr->head) {
> + unsigned cq_mask = CQ_ENTRIES - 1;
> +
> + cqe = &cqes[cq_hdr->head++ & cq_mask];
> + bpf_printk("found cqe: data %lu res %i",
> + (unsigned long)cqe->user_data, (int)cqe->res);
> +
> + int left = --reqs_to_run;
> + if (left <= 0) {
> + bpf_printk("finished");
> + return IOU_LOOP_STOP;
> + }
> + }
> +
> + bpf_printk("queue nop request, data %lu\n", (unsigned long)reqs_to_run);
> + sqe = &sqes[sq_hdr->tail & (SQ_ENTRIES - 1)];
> + sqe->user_data = reqs_to_run;
> + sq_hdr->tail++;
Looks this way turns io_uring_enter() into pthread-unsafe, does it need to
be documented?
Thanks,
Ming
next prev parent reply other threads:[~2025-11-14 13:09 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-13 11:59 [PATCH v3 00/10] BPF controlled io_uring Pavel Begunkov
2025-11-13 11:59 ` [PATCH v3 01/10] io_uring: rename the wait queue entry field Pavel Begunkov
2025-11-13 11:59 ` [PATCH v3 02/10] io_uring: simplify io_cqring_wait_schedule results Pavel Begunkov
2025-11-13 11:59 ` [PATCH v3 03/10] io_uring: export __io_run_local_work Pavel Begunkov
2025-11-13 11:59 ` [PATCH v3 04/10] io_uring: extract waiting parameters into a struct Pavel Begunkov
2025-11-13 11:59 ` [PATCH v3 05/10] io_uring/bpf: add stubs for bpf struct_ops Pavel Begunkov
2025-11-13 11:59 ` [PATCH v3 06/10] io_uring/bpf: add handle events callback Pavel Begunkov
2025-11-13 11:59 ` [PATCH v3 07/10] io_uring/bpf: implement struct_ops registration Pavel Begunkov
2025-11-24 3:44 ` Ming Lei
2025-11-24 13:12 ` Pavel Begunkov
2025-11-24 14:29 ` Ming Lei
2025-11-25 12:46 ` Pavel Begunkov
2025-11-13 11:59 ` [PATCH v3 08/10] io_uring/bpf: add basic kfunc helpers Pavel Begunkov
2025-11-13 11:59 ` [PATCH v3 09/10] selftests/io_uring: update mini liburing Pavel Begunkov
2025-11-13 11:59 ` [PATCH v3 10/10] selftests/io_uring: add bpf io_uring selftests Pavel Begunkov
2025-11-14 13:08 ` Ming Lei [this message]
2025-11-19 19:00 ` Pavel Begunkov
2025-11-20 1:41 ` Ming Lei
2025-11-21 16:12 ` Pavel Begunkov
2025-11-22 0:19 ` Ming Lei
2025-11-24 11:57 ` Pavel Begunkov
2025-11-24 13:28 ` Ming Lei
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=aRcp5Gi41i-g64ov@fedora \
--to=ming.lei@redhat.com \
--cc=alexei.starovoitov@gmail.com \
--cc=andrii@kernel.org \
--cc=asml.silence@gmail.com \
--cc=axboe@kernel.dk \
--cc=bpf@vger.kernel.org \
--cc=io-uring@vger.kernel.org \
--cc=martin.lau@linux.dev \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.