This patch set generalizes XDP by make the hooks in drivers to be generic in the same manner of nfhooks. This has a number of advantages:
- Allows alternative users of the XDP hooks other than the original BPF - Allows a means to pipeline XDP programs together - Reduces the amount of code and complexity needed in drivers to manage XDP - Provides a more structured environment that is extensible to new features while being mostly transparent to the drivers The generic XDP infrastructure is based on how nfhooks works. The new xdp_hook_ops structure contains callback functions and private data structure that can be populated by the user of XDP. The hook ops are registered either on a netdev or a napi (both maintain a list of XDP hook ops). Allow per netdev ops makes management of XDP a lot simpler when the intent is for the hook to apply to the whole driver (as is the case with XDP_BPF so far). The downside is that we may need per napi data (such as counters of returned actions). The xdp_hook_ops contains three fields of interest. The "hook" field is the function that is run for the hook. This takes a private data field and the xdp_buff as arguments. "priv" is private data and "put_priv" is a function called when XDP is done with the private data. In XDP_BPF terminology the hook field is bpf_prog_run_xdp, "priv" is the xdp_prog, and "put_priv" is bpf_prog_put. The meaning of ndo_xdp is also changed. There are two commands for this nod: XDP_DEV_INIT and XDP_DEV_FINISH. XDP_DEV_INIT is called the first time an XDP hook is set on a device, this is primarily intended to allow the device to initialize XDP (allocated the XDP TX queues for instance). XDP_DEV_FINISH is called when the last XDP hook is removed from a driver so that the driver can cleanup when XDP is done. A new net feature is added NETIF_F_XDP so that a driver indicates that is supports XDP. The primary modification to a driver to support XDP is that it call xdp_hook_run in the receive path (equivalent to bpf_prog_run in previous XDP-BPF). The driver must deal with the four XDP return actions XDP_PASS, XDP_DROP, XDP_TX, and XDP_ABORT. xdp.h contains the interface to register and manage XDP hooks. Tested: Created a simple hook that does XDP_PASS and saw it works. A lot more testing is needed for this. Tom Herbert (3): xdp: Infrastructure to generalize XDP mlx4: Change XDP/BPF to use generic XDP infrastructure netdevice: Remove obsolete xdp_netdev_command drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 64 ++------ drivers/net/ethernet/mellanox/mlx4/en_rx.c | 25 ++- drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 1 - include/linux/filter.h | 19 +-- include/linux/netdev_features.h | 3 +- include/linux/netdevice.h | 24 ++- include/net/xdp.h | 218 +++++++++++++++++++++++++ include/uapi/linux/bpf.h | 20 --- include/uapi/linux/xdp.h | 24 +++ net/core/Makefile | 2 +- net/core/dev.c | 44 ++++- net/core/filter.c | 7 +- net/core/rtnetlink.c | 16 +- net/core/xdp.c | 211 ++++++++++++++++++++++++ 14 files changed, 534 insertions(+), 144 deletions(-) create mode 100644 include/net/xdp.h create mode 100644 include/uapi/linux/xdp.h create mode 100644 net/core/xdp.c -- 2.8.0.rc2