From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f54.google.com (mail-wm1-f54.google.com [209.85.128.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E7C7F2737F2 for ; Mon, 16 Feb 2026 16:51:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.54 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771260714; cv=none; b=qs189EvYyucRkiFGLkjdGlWY45YVxmAq5gJPZNcOtiLI8/WEz7r0aXSAtW7DfVk9Sk0zmS1kbdUjFV3r0CPmjOpVeurorlF143p3SgzlZzDrnQvK6Hw9J4zr631lA2aOOg2snAlzcP3pcwtnRVZt//2uI+xJ2f9NFTviRn8kkSc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771260714; c=relaxed/simple; bh=QE96R9eicSGpjinXpGU8uaHaRIew9YzdrFxbUp3vIgM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NlHUjkP5Fhf+p1zgW+M/Vwmn4Pa9mHOAdV/WyDPFZjQTUJOGlbsmqRZl6pHq2XrIzMDoIBfk42zPbYPTN/dpLNgxI3gcO7uQrMH1woYbG9plC8CH4nzhMpj8217cS4sIqSjhE4WcmcNJWTERUTPblAjdWLmzehPWYVbVIvLSbVA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=AEuRRMVa; arc=none smtp.client-ip=209.85.128.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="AEuRRMVa" Received: by mail-wm1-f54.google.com with SMTP id 5b1f17b1804b1-483770e0b25so28719015e9.0 for ; Mon, 16 Feb 2026 08:51:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1771260710; x=1771865510; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=x44aAcQjnWa1QWZK/N7Lh2pdpMQOoZvekrVC+aS3QjU=; b=AEuRRMVa98nEBKG2qQfT8RepXphEUpC4YVUkXgtdIolBu3jzrP1QqIHSEFZVNmBx1i RnjCQHGUEzQ1cD1a1O7XREJEJa4HxjREGYdsycsHE8yIUZrhIML8joaxQa2/Jpt/C6NY Rz4275LuPBMBWDy0oPnPJXGUInlEhRmmqaFMuz/GDLURJ5VOsgIldbF0SROiVw2CLA6L IShGPMyhTXIl+jywTscP/NMW1FHavA46eFr8mIxxyPcrxM6aePrSPJuQX5H72PW4MpGg BIXzbUiQCnnF0ww9vaTpmNweI4EDowvrjo98drujvuCkcjFt/gHzt8S1HjfE/KeKyBuU HRvA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1771260710; x=1771865510; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=x44aAcQjnWa1QWZK/N7Lh2pdpMQOoZvekrVC+aS3QjU=; b=NTbOFfzSIw3Agsgbp/CsM4UKoNV3EziZZ/Vb9UBipWmMjZHwx/NZLmyHMeg5nHJxhZ +DFcnz4EOuVhJ9laJAhdFrt6K06FP+aNJ9C2qfiCUyuB0tSbCna0Mr6Qujl7HShZ+oRu 6GfPhsphrt9YUmyNlPUS4F22RUwxf9sFsmRfcAzDdsnqhmzVH7NQOsP3Kfo8PPrR0kGI Hu2QIblt1OWQzH5iclZbRsrr5f1eLfOpdNRzyuZ0uu9pYfaRcQKF+OMLv0Us7PQw3Hv5 Gp8MPFg3j29dNNJBuoj7JKwsAJmRcPbUVNlhwp/AfyG/aIlWF02s0hl5oCoM+HsmZcgA f3NA== X-Gm-Message-State: AOJu0Yx4XpbWVdBmzQVwSDyUFjEATlrv+3DY24LbUYIp1x4ZkyI9Sjqt 4U9pNGYhuatn8w7VGdIvu0P/NP3fw3q2wLlj6zP2zRG2eUD6h5enzrCazUKcc48A X-Gm-Gg: AZuq6aJI7OWS0GEUV0OW217M2EYegl6ROneD7uCk4ITQA59sSYB+UX98uL8VT0TrOlu rg2oUYwyWh+AXehcR8SzhK3immYdg49FbM3LbHtQVSs9dzhhT6AnChromjdiIbiIekQMhsOwuFy Es423yi1JO3Zi7DyIh9MfI9uIXUl+n+7kTdAzDJY1kLmwUbjkGz+jkwgziBTZMmxXSPVGKS5vOz xDoCeVoPcq3wKqM5qgnmPCwuVXs/bdgSfEVFNwMRdE8oAJXxBbL+V6IBIBPexxZR9iK9fu7AhUW RvV5j9zYeMYWwx5N1xzpCBm9BMAa5qUVFUZsLaRQ5AoquW6vUnYdUv6KdKLAyO3OlK3NM0EbneB /k2Qfk4YJlR00sT3rPzYElAYAvbM+qgHrshvgUNEu6LPfg5w3PoESxrIxK4QYfLkirPmM7C/rLW AM/p3N8RIjZQwopSA8rqVsqOIMapxtPB8nHluOJBjbSA+gdzvfFzm1K1zw+8MEdQMXnGDsw++f+ /n9fKfc X-Received: by 2002:a05:600c:348e:b0:47e:e2ec:9947 with SMTP id 5b1f17b1804b1-483710960eamr219840995e9.33.1771260709783; Mon, 16 Feb 2026 08:51:49 -0800 (PST) Received: from 127.com ([2620:10d:c092:600::1:c3fa]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4837b64b08bsm76454255e9.6.2026.02.16.08.51.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 16 Feb 2026 08:51:49 -0800 (PST) From: Pavel Begunkov To: io-uring@vger.kernel.org Cc: asml.silence@gmail.com, bpf@vger.kernel.org, axboe@kernel.dk, Alexei Starovoitov Subject: [PATCH v7 3/5] io_uring/bpf-ops: add kfunc helpers Date: Mon, 16 Feb 2026 16:51:24 +0000 Message-ID: X-Mailer: git-send-email 2.52.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 --- io_uring/bpf-ops.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++ io_uring/bpf-ops.h | 6 +++++ 2 files changed, 61 insertions(+) diff --git a/io_uring/bpf-ops.c b/io_uring/bpf-ops.c index ea9c062a4d9f..1cc4fc647add 100644 --- a/io_uring/bpf-ops.c +++ b/io_uring/bpf-ops.c @@ -5,11 +5,58 @@ #include "io_uring.h" #include "register.h" +#include "memmap.h" #include "bpf-ops.h" #include "loop.h" static const struct btf_type *loop_params_type; +__bpf_kfunc_start_defs(); + +__bpf_kfunc int bpf_io_uring_submit_sqes(struct io_ring_ctx *ctx, u32 nr) +{ + return io_submit_sqes(ctx, nr); +} + +__bpf_kfunc +__u8 *bpf_io_uring_get_region(struct io_ring_ctx *ctx, __u32 region_id, + const size_t rdwr_buf_size) +{ + struct io_mapped_region *r; + + lockdep_assert_held(&ctx->uring_lock); + + switch (region_id) { + case IOU_REGION_MEM: + r = &ctx->param_region; + break; + case IOU_REGION_CQ: + r = &ctx->ring_region; + break; + case IOU_REGION_SQ: + r = &ctx->sq_region; + break; + default: + return NULL; + } + + if (unlikely(rdwr_buf_size > io_region_size(r))) + return NULL; + return io_region_get_ptr(r); +} + +__bpf_kfunc_end_defs(); + +BTF_KFUNCS_START(io_uring_kfunc_set) +BTF_ID_FLAGS(func, bpf_io_uring_submit_sqes, KF_SLEEPABLE); +BTF_ID_FLAGS(func, bpf_io_uring_get_region, KF_RET_NULL); +BTF_KFUNCS_END(io_uring_kfunc_set) + +static const struct btf_kfunc_id_set bpf_io_uring_kfunc_set = { + .owner = THIS_MODULE, + .set = &io_uring_kfunc_set, +}; + static int io_bpf_ops__loop_step(struct io_ring_ctx *ctx, struct iou_loop_params *lp) { @@ -69,12 +116,20 @@ io_lookup_struct_type(struct btf *btf, const char *name) static int bpf_io_init(struct btf *btf) { + int ret; + loop_params_type = io_lookup_struct_type(btf, "iou_loop_params"); if (!loop_params_type) { pr_err("io_uring: Failed to locate iou_loop_params\n"); return -EINVAL; } + ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, + &bpf_io_uring_kfunc_set); + if (ret) { + pr_err("io_uring: Failed to register kfuncs (%d)\n", ret); + return ret; + } return 0; } diff --git a/io_uring/bpf-ops.h b/io_uring/bpf-ops.h index e8a08ae2df0a..b9e589ad519a 100644 --- a/io_uring/bpf-ops.h +++ b/io_uring/bpf-ops.h @@ -4,6 +4,12 @@ #include +enum { + IOU_REGION_MEM, + IOU_REGION_CQ, + IOU_REGION_SQ, +}; + struct io_uring_bpf_ops { int (*loop_step)(struct io_ring_ctx *ctx, struct iou_loop_params *lp); -- 2.52.0