mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-05-05 09:57:21 +02:00
Pavel Begunkov
825f276491
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 receive path in the future if improved. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://patch.msgid.link/674f8ad679c5a0bc79d538352b3042cf0999596e.1774261953.git.asml.silence@gmail.com [axboe: fix spelling error in uapi header and commit message] Signed-off-by: Jens Axboe <axboe@kernel.dk>
116 lines
2.2 KiB
C
116 lines
2.2 KiB
C
/* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR MIT */
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/*
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* Header file for the io_uring zerocopy receive (zcrx) interface.
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*
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* Copyright (C) 2026 Pavel Begunkov
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* Copyright (C) 2026 David Wei
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* Copyright (C) Meta Platforms, Inc.
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*/
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#ifndef LINUX_IO_ZCRX_H
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#define LINUX_IO_ZCRX_H
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#include <linux/types.h>
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/* Zero copy receive refill queue entry */
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struct io_uring_zcrx_rqe {
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__u64 off;
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__u32 len;
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__u32 __pad;
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};
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struct io_uring_zcrx_cqe {
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__u64 off;
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__u64 __pad;
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};
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/* The bit from which area id is encoded into offsets */
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#define IORING_ZCRX_AREA_SHIFT 48
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#define IORING_ZCRX_AREA_MASK (~(((__u64)1 << IORING_ZCRX_AREA_SHIFT) - 1))
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struct io_uring_zcrx_offsets {
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__u32 head;
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__u32 tail;
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__u32 rqes;
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__u32 __resv2;
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__u64 __resv[2];
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};
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enum io_uring_zcrx_area_flags {
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IORING_ZCRX_AREA_DMABUF = 1,
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};
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struct io_uring_zcrx_area_reg {
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__u64 addr;
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__u64 len;
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__u64 rq_area_token;
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__u32 flags;
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__u32 dmabuf_fd;
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__u64 __resv2[2];
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};
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enum zcrx_reg_flags {
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ZCRX_REG_IMPORT = 1,
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/*
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* Register a zcrx instance without a net device. All data will be
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* copied. The refill queue entries might not be automatically
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* consumed and need to be flushed, see ZCRX_CTRL_FLUSH_RQ.
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*/
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ZCRX_REG_NODEV = 2,
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};
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enum zcrx_features {
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/*
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* The user can ask for the desired rx page size by passing the
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* value in struct io_uring_zcrx_ifq_reg::rx_buf_len.
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*/
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ZCRX_FEATURE_RX_PAGE_SIZE = 1 << 0,
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};
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/*
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* Argument for IORING_REGISTER_ZCRX_IFQ
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*/
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struct io_uring_zcrx_ifq_reg {
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__u32 if_idx;
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__u32 if_rxq;
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__u32 rq_entries;
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__u32 flags;
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__u64 area_ptr; /* pointer to struct io_uring_zcrx_area_reg */
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__u64 region_ptr; /* struct io_uring_region_desc * */
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struct io_uring_zcrx_offsets offsets;
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__u32 zcrx_id;
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__u32 rx_buf_len;
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__u64 __resv[3];
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};
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enum zcrx_ctrl_op {
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ZCRX_CTRL_FLUSH_RQ,
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ZCRX_CTRL_EXPORT,
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__ZCRX_CTRL_LAST,
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};
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struct zcrx_ctrl_flush_rq {
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__u64 __resv[6];
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};
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struct zcrx_ctrl_export {
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__u32 zcrx_fd;
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__u32 __resv1[11];
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};
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struct zcrx_ctrl {
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__u32 zcrx_id;
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__u32 op; /* see enum zcrx_ctrl_op */
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__u64 __resv[2];
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union {
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struct zcrx_ctrl_export zc_export;
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struct zcrx_ctrl_flush_rq zc_flush;
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};
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};
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#endif /* LINUX_IO_ZCRX_H */
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