From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f44.google.com (mail-wr1-f44.google.com [209.85.221.44]) (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 7A2CA3AA1B6 for ; Mon, 23 Mar 2026 12:44:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.44 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774269853; cv=none; b=pR4cskjnRnTvKS2AiNXdM8jmwJ/zYRcLf5IOX1j2jGL8Smj69nRoOKOwLmZhPc2o7gV/dOomFfr5GbvxT2Foe8ik5hIh3whImWPlyNUhArEaqxSqSwHqwUeDYfyyVeMP8A9uFHwbdZXsO6sE8r848Hh07vvOWzhU/PS8l6LYJK0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774269853; c=relaxed/simple; bh=BJCDSk/ikO5vcGJQqSK3RBpbIbBN6G40dJabdP4kfJo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UUYw5xrLc/cB61/YL2V9gIz3WFcYi3ZQppKF87/Sx6aSSUjYIalf54C3O/2hc8Wzmm2Pj4kFzHWLgH7hp/WDHmtDjLvgA8R5Cj2g3FVI7Ozv8QyXGKR2PMpAc6hv4SP1htXaCeb/pEK3rmbrMS5i3lCwU5aj3RN4lLmK6Plx9cI= 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=mxv0/S2s; arc=none smtp.client-ip=209.85.221.44 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="mxv0/S2s" Received: by mail-wr1-f44.google.com with SMTP id ffacd0b85a97d-43b7c844b20so459561f8f.3 for ; Mon, 23 Mar 2026 05:44:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1774269849; x=1774874649; 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=q3SpE6pAv0CHtcxGEAqgEZJYKI2Qu5Y7W2dacp60yPU=; b=mxv0/S2sMvU64OioBRusNYVWWBbHLIk7YvTt/fUm6KOxRiPIbqNOTgTPhFvNGah+oA EwU8mV4I3q6759NGulu10W91WJMy+UQTrRiIX18fb3hXKuVMujY7hnpN0SnkwaehGhjE t7fjxutwmYkC/1oNkkdYpHr3eNtJe3X5+hjzY254LJVCNw6JfOQjyDQGDLrdWPJHpm/z BPXYu7mh1O/5Mq995ziFTs3SRRwSMArJBqBd9KRoayVdgBkYFdPo9L9pF6GUobR7b6k3 ++WWZq5Ir6VT6JM2dkLZnngyFinnCytCpesrFqOByFJPbkCrcqd2KTo63G9TYql65Ede ACZg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1774269849; x=1774874649; 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=q3SpE6pAv0CHtcxGEAqgEZJYKI2Qu5Y7W2dacp60yPU=; b=IseqLE3m8QK4kHX9CJczH4F81vvCG5gSBXjsi+KWgjaWDA5zenZ6Kn+Uv72W1Q1oBS iBH3NqDknlgAHjq8A/itqUW81prh9LDZgUw6jymWiqYPqrhwBSSSOLp8Eyu1wUr1of0S Ast8RcuZZoPBqD5vEz/PNePjsJFnsLjDSENy8Gc5vDNYwGrSMy98t42f++EmI9MBlJd3 JeKoJLQi2XqlP6cM9yPvJvAK8BVdDTfWjqOZ1TcHPSyBz7J9zy7n5vYEd3z6Km/Upiv/ Y6ulU1wXk+oogyVKRj6JFJXXUt3q/g5i1TZXAgIzxR0LTjoGmj7DkyWSjJ+Ur2XeZKzU PANw== X-Gm-Message-State: AOJu0YwlyyVeoClno6ibHtCMmlrGjkrYsq74O6RFLXVTcJmVHLSInaoL Ll4HfH4c2mm9FxAl6s0FYtHMlb5+O3fbwaRjQl/2/5jh/B+pzzWVpYRqeV9+SQ== X-Gm-Gg: ATEYQzx++R616Yf492vJOrJ68UpAR+lVV8jt90vg+qTAE5pV0W/xsgqpswklyEfds12 gZDIWzViKlDNCbr84/6W6G8UoCKMH8K7sJXInZ9G0RDzGrQMYsHNWOneMOQT7IKNCizIN1+iagD ZH8wLt9kd1z8jrpYwEGfgxw5MfjowTNPqMjou8zHBTeOQF8/16+PAZZuS0yj0XdEquabpRc4Fdr BeDz2S4ZNyI9b5LQWlCq5ZECmhEP4AuSDOK6qHO+TYm1HO7o+030WnyZQsvDY5zPIHBFisfCEUW y1fOAt54nuUIHqljKvx/M0QIDQOapk8fccP/HZzeJRTS25iooBtcWYU/UEfZ4Qij/ihEW0U1KCr dHlt3sW6QMA7mgxHuALp4qhKZPDiaJvFWOBSWCiJ18Eaqd7OL8PqGlesv/PGIIa6t1E4JlDSB0y Mwc7UPgIrgqKeIvj24CVMtShBE+aHQ0Z6LSBNNXeKxv4P4mMExXIFe+9ovYuNphgPh9UoK+9AbO RI3V78hCw== X-Received: by 2002:a05:6000:2484:b0:43b:4c6b:754a with SMTP id ffacd0b85a97d-43b6427b552mr18767045f8f.53.1774269848642; Mon, 23 Mar 2026 05:44:08 -0700 (PDT) Received: from 127.com ([2620:10d:c092:600::1:6969]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-43b6425eeb4sm25520861f8f.0.2026.03.23.05.44.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 Mar 2026 05:44:07 -0700 (PDT) From: Pavel Begunkov To: io-uring@vger.kernel.org Cc: asml.silence@gmail.com, axboe@kernel.dk, netdev@vger.kernel.org Subject: [PATCH io_uring-7.1 05/16] io_uring/zcrx: implement device-less mode for zcrx Date: Mon, 23 Mar 2026 12:43:54 +0000 Message-ID: <674f8ad679c5a0bc79d538352b3042cf0999596e.1774261953.git.asml.silence@gmail.com> X-Mailer: git-send-email 2.53.0 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 Allow creating a zcrx instance without attaching it to a net device. All data will be copied through the fallback path. The user is also expected to use ZCRX_CTRL_FLUSH_RQ to handle overflows as it normally should even with a netdev, but it becomes even more relevant as there will likely be no one to automatically pick up buffers. Apart from that, it follows the zcrx uapi for the I/O path, and is useful for testing, experimentation, and potentially for the copy recieve path in the future if improved. Signed-off-by: Pavel Begunkov --- include/uapi/linux/io_uring/zcrx.h | 9 ++++++- io_uring/zcrx.c | 41 ++++++++++++++++++++---------- io_uring/zcrx.h | 2 +- 3 files changed, 36 insertions(+), 16 deletions(-) diff --git a/include/uapi/linux/io_uring/zcrx.h b/include/uapi/linux/io_uring/zcrx.h index 3163a4b8aeb0..103d65e690eb 100644 --- a/include/uapi/linux/io_uring/zcrx.h +++ b/include/uapi/linux/io_uring/zcrx.h @@ -49,7 +49,14 @@ struct io_uring_zcrx_area_reg { }; enum zcrx_reg_flags { - ZCRX_REG_IMPORT = 1, + ZCRX_REG_IMPORT = 1, + + /* + * Register a zcrx instance without a net device. All data will be + * copied. The refill queue entries might not be automatically + * consmumed and need to be flushed, see ZCRX_CTRL_FLUSH_RQ. + */ + ZCRX_REG_NODEV = 2, }; enum zcrx_features { diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c index d2798a82c678..d772e1609c4b 100644 --- a/io_uring/zcrx.c +++ b/io_uring/zcrx.c @@ -127,10 +127,10 @@ static int io_import_dmabuf(struct io_zcrx_ifq *ifq, int dmabuf_fd = area_reg->dmabuf_fd; int i, ret; + if (!ifq->dev) + return -EINVAL; if (off) return -EINVAL; - if (WARN_ON_ONCE(!ifq->dev)) - return -EFAULT; if (!IS_ENABLED(CONFIG_DMA_SHARED_BUFFER)) return -EINVAL; @@ -211,11 +211,13 @@ static int io_import_umem(struct io_zcrx_ifq *ifq, if (ret) goto out_err; - ret = dma_map_sgtable(ifq->dev, &mem->page_sg_table, - DMA_FROM_DEVICE, IO_DMA_ATTR); - if (ret < 0) - goto out_err; - mapped = true; + if (ifq->dev) { + ret = dma_map_sgtable(ifq->dev, &mem->page_sg_table, + DMA_FROM_DEVICE, IO_DMA_ATTR); + if (ret < 0) + goto out_err; + mapped = true; + } mem->account_pages = io_count_account_pages(pages, nr_pages); ret = io_account_mem(ifq->user, ifq->mm_account, mem->account_pages); @@ -450,7 +452,8 @@ static int io_zcrx_create_area(struct io_zcrx_ifq *ifq, ret = io_import_area(ifq, &area->mem, area_reg); if (ret) goto err; - area->is_mapped = true; + if (ifq->dev) + area->is_mapped = true; if (buf_size_shift > io_area_max_shift(&area->mem)) { ret = -ERANGE; @@ -486,9 +489,11 @@ static int io_zcrx_create_area(struct io_zcrx_ifq *ifq, niov->type = NET_IOV_IOURING; } - ret = io_populate_area_dma(ifq, area); - if (ret) - goto err; + if (ifq->dev) { + ret = io_populate_area_dma(ifq, area); + if (ret) + goto err; + } area->free_count = nr_iovs; /* we're only supporting one area per ifq for now */ @@ -826,6 +831,8 @@ int io_register_zcrx_ifq(struct io_ring_ctx *ctx, return -EFAULT; if (reg.if_rxq == -1 || !reg.rq_entries) return -EINVAL; + if ((reg.if_rxq || reg.if_idx) && (reg.flags & ZCRX_REG_NODEV)) + return -EINVAL; if (reg.rq_entries > IO_RQ_MAX_ENTRIES) { if (!(ctx->flags & IORING_SETUP_CLAMP)) return -EINVAL; @@ -861,9 +868,15 @@ int io_register_zcrx_ifq(struct io_ring_ctx *ctx, if (ret) goto err; - ret = zcrx_register_netdev(ifq, ®, &area); - if (ret) - goto err; + if (!(reg.flags & ZCRX_REG_NODEV)) { + ret = zcrx_register_netdev(ifq, ®, &area); + if (ret) + goto err; + } else { + ret = io_zcrx_create_area(ifq, &area, ®); + if (ret) + goto err; + } reg.zcrx_id = id; diff --git a/io_uring/zcrx.h b/io_uring/zcrx.h index 0316a41a3561..f395656c3160 100644 --- a/io_uring/zcrx.h +++ b/io_uring/zcrx.h @@ -8,7 +8,7 @@ #include #include -#define ZCRX_SUPPORTED_REG_FLAGS (ZCRX_REG_IMPORT) +#define ZCRX_SUPPORTED_REG_FLAGS (ZCRX_REG_IMPORT | ZCRX_REG_NODEV) #define ZCRX_FEATURES (ZCRX_FEATURE_RX_PAGE_SIZE) struct io_zcrx_mem { -- 2.53.0