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From:   Pavel Begunkov <asml.silence@gmail.com>
To:     io-uring@vger.kernel.org, netdev@vger.kernel.org,
        bpf@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     Jens Axboe <axboe@kernel.dk>, Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>,
        Horst Schirmeier <horst.schirmeier@tu-dortmund.de>,
        "Franz-B . Tuneke" <franz-bernhard.tuneke@tu-dortmund.de>,
        Christian Dietrich <stettberger@dokucode.de>
Subject: [PATCH 16/23] io_uring: enable bpf to submit CQEs
Date:   Wed, 19 May 2021 15:13:27 +0100
Message-Id: <b30d850d24bd7fb926bc0f60a4e3e2e62e90838f.1621424513.git.asml.silence@gmail.com>
In-Reply-To: <cover.1621424513.git.asml.silence@gmail.com>
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Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 fs/io_uring.c            | 36 ++++++++++++++++++++++++++++++++++++
 include/uapi/linux/bpf.h |  1 +
 2 files changed, 37 insertions(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index aae786291c57..464d630904e2 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -10371,6 +10371,29 @@ BPF_CALL_3(io_bpf_queue_sqe, struct io_bpf_ctx *,		bpf_ctx,
 	return !io_submit_sqe(ctx, req, sqe);
 }
 
+BPF_CALL_5(io_bpf_emit_cqe, struct io_bpf_ctx *,		bpf_ctx,
+			    u32,				cq_idx,
+			    u64,				user_data,
+			    s32,				res,
+			    u32,				flags)
+{
+	struct io_ring_ctx *ctx = bpf_ctx->ctx;
+	bool submitted;
+
+	if (unlikely(cq_idx >= ctx->cq_nr))
+		return -EINVAL;
+
+	spin_lock_irq(&ctx->completion_lock);
+	submitted = io_cqring_fill_event(ctx, user_data, res, flags, cq_idx);
+	io_commit_cqring(ctx);
+	ctx->cq_extra++;
+	spin_unlock_irq(&ctx->completion_lock);
+	if (submitted)
+		io_cqring_ev_posted(ctx);
+
+	return submitted ? 0 : -ENOMEM;
+}
+
 const struct bpf_func_proto io_bpf_queue_sqe_proto = {
 	.func = io_bpf_queue_sqe,
 	.gpl_only = false,
@@ -10380,6 +10403,17 @@ const struct bpf_func_proto io_bpf_queue_sqe_proto = {
 	.arg3_type = ARG_CONST_SIZE,
 };
 
+const struct bpf_func_proto io_bpf_emit_cqe_proto = {
+	.func = io_bpf_emit_cqe,
+	.gpl_only = false,
+	.ret_type = RET_INTEGER,
+	.arg1_type = ARG_PTR_TO_CTX,
+	.arg2_type = ARG_ANYTHING,
+	.arg3_type = ARG_ANYTHING,
+	.arg4_type = ARG_ANYTHING,
+	.arg5_type = ARG_ANYTHING,
+};
+
 static const struct bpf_func_proto *
 io_bpf_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 {
@@ -10388,6 +10422,8 @@ io_bpf_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL;
 	case BPF_FUNC_iouring_queue_sqe:
 		return prog->aux->sleepable ? &io_bpf_queue_sqe_proto : NULL;
+	case BPF_FUNC_iouring_emit_cqe:
+		return &io_bpf_emit_cqe_proto;
 	default:
 		return bpf_base_func_proto(func_id);
 	}
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index cc268f749a7d..c6b023be7848 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -4083,6 +4083,7 @@ union bpf_attr {
 	FN(sock_from_file),		\
 	FN(check_mtu),			\
 	FN(iouring_queue_sqe),		\
+	FN(iouring_emit_cqe),		\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
-- 
2.31.1