linux-stable/include/uapi/linux/if_xdp.h
Tirthendu Sarkar 81470b5c3c xsk: introduce XSK_USE_SG bind flag for xsk socket
As of now xsk core drops any xdp_buff with data size greater than the
xsk frame_size as set by the af_xdp application. With multi-buffer
support introduced in the next patch xsk core can now split those
buffers into multiple descriptors provided the af_xdp application can
handle them. Such capability of the application needs to be independent
of the xdp_prog's frag support capability since there are cases where
even a single xdp_buffer may need to be split into multiple descriptors
owing to a smaller xsk frame size.

For e.g., with NIC rx_buffer size set to 4kB, a 3kB packet will
constitute of a single buffer and so will be sent as such to AF_XDP layer
irrespective of 'xdp.frags' capability of the XDP program. Now if the xsk
frame size is set to 2kB by the AF_XDP application, then the packet will
need to be split into 2 descriptors if AF_XDP application can handle
multi-buffer, else it needs to be dropped.

Applications can now advertise their frag handling capability to xsk core
so that xsk core can decide if it should drop or split xdp_buffs that
exceed xsk frame size. This is done using a new 'XSK_USE_SG' bind flag
for the xdp socket.

Signed-off-by: Tirthendu Sarkar <tirthendu.sarkar@intel.com>
Link: https://lore.kernel.org/r/20230719132421.584801-3-maciej.fijalkowski@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-07-19 09:56:48 -07:00

124 lines
3.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
* if_xdp: XDP socket user-space interface
* Copyright(c) 2018 Intel Corporation.
*
* Author(s): Björn Töpel <bjorn.topel@intel.com>
* Magnus Karlsson <magnus.karlsson@intel.com>
*/
#ifndef _LINUX_IF_XDP_H
#define _LINUX_IF_XDP_H
#include <linux/types.h>
/* Options for the sxdp_flags field */
#define XDP_SHARED_UMEM (1 << 0)
#define XDP_COPY (1 << 1) /* Force copy-mode */
#define XDP_ZEROCOPY (1 << 2) /* Force zero-copy mode */
/* If this option is set, the driver might go sleep and in that case
* the XDP_RING_NEED_WAKEUP flag in the fill and/or Tx rings will be
* set. If it is set, the application need to explicitly wake up the
* driver with a poll() (Rx and Tx) or sendto() (Tx only). If you are
* running the driver and the application on the same core, you should
* use this option so that the kernel will yield to the user space
* application.
*/
#define XDP_USE_NEED_WAKEUP (1 << 3)
/* By setting this option, userspace application indicates that it can
* handle multiple descriptors per packet thus enabling AF_XDP to split
* multi-buffer XDP frames into multiple Rx descriptors. Without this set
* such frames will be dropped.
*/
#define XDP_USE_SG (1 << 4)
/* Flags for xsk_umem_config flags */
#define XDP_UMEM_UNALIGNED_CHUNK_FLAG (1 << 0)
struct sockaddr_xdp {
__u16 sxdp_family;
__u16 sxdp_flags;
__u32 sxdp_ifindex;
__u32 sxdp_queue_id;
__u32 sxdp_shared_umem_fd;
};
/* XDP_RING flags */
#define XDP_RING_NEED_WAKEUP (1 << 0)
struct xdp_ring_offset {
__u64 producer;
__u64 consumer;
__u64 desc;
__u64 flags;
};
struct xdp_mmap_offsets {
struct xdp_ring_offset rx;
struct xdp_ring_offset tx;
struct xdp_ring_offset fr; /* Fill */
struct xdp_ring_offset cr; /* Completion */
};
/* XDP socket options */
#define XDP_MMAP_OFFSETS 1
#define XDP_RX_RING 2
#define XDP_TX_RING 3
#define XDP_UMEM_REG 4
#define XDP_UMEM_FILL_RING 5
#define XDP_UMEM_COMPLETION_RING 6
#define XDP_STATISTICS 7
#define XDP_OPTIONS 8
struct xdp_umem_reg {
__u64 addr; /* Start of packet data area */
__u64 len; /* Length of packet data area */
__u32 chunk_size;
__u32 headroom;
__u32 flags;
};
struct xdp_statistics {
__u64 rx_dropped; /* Dropped for other reasons */
__u64 rx_invalid_descs; /* Dropped due to invalid descriptor */
__u64 tx_invalid_descs; /* Dropped due to invalid descriptor */
__u64 rx_ring_full; /* Dropped due to rx ring being full */
__u64 rx_fill_ring_empty_descs; /* Failed to retrieve item from fill ring */
__u64 tx_ring_empty_descs; /* Failed to retrieve item from tx ring */
};
struct xdp_options {
__u32 flags;
};
/* Flags for the flags field of struct xdp_options */
#define XDP_OPTIONS_ZEROCOPY (1 << 0)
/* Pgoff for mmaping the rings */
#define XDP_PGOFF_RX_RING 0
#define XDP_PGOFF_TX_RING 0x80000000
#define XDP_UMEM_PGOFF_FILL_RING 0x100000000ULL
#define XDP_UMEM_PGOFF_COMPLETION_RING 0x180000000ULL
/* Masks for unaligned chunks mode */
#define XSK_UNALIGNED_BUF_OFFSET_SHIFT 48
#define XSK_UNALIGNED_BUF_ADDR_MASK \
((1ULL << XSK_UNALIGNED_BUF_OFFSET_SHIFT) - 1)
/* Rx/Tx descriptor */
struct xdp_desc {
__u64 addr;
__u32 len;
__u32 options;
};
/* UMEM descriptor is __u64 */
/* Flag indicating that the packet continues with the buffer pointed out by the
* next frame in the ring. The end of the packet is signalled by setting this
* bit to zero. For single buffer packets, every descriptor has 'options' set
* to 0 and this maintains backward compatibility.
*/
#define XDP_PKT_CONTD (1 << 0)
#endif /* _LINUX_IF_XDP_H */