Commit fc45c5b6 authored by Stanislav Fomichev's avatar Stanislav Fomichev Committed by Martin KaFai Lau
Browse files

bpf: make it easier to add new metadata kfunc 



No functional changes.

Instead of having hand-crafted code in bpf_dev_bound_resolve_kfunc,
move kfunc <> xmo handler relationship into XDP_METADATA_KFUNC_xxx.
This way, any time new kfunc is added, we don't have to touch
bpf_dev_bound_resolve_kfunc.

Also document XDP_METADATA_KFUNC_xxx arguments since we now have
more than two and it might be confusing what is what.

Cc: netdev@vger.kernel.org
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: default avatarStanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230913171350.369987-2-sdf@google.com


Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
parent d609f3d2

include/net/xdp.h

+12 −4
Original line number Diff line number Diff line
@@ -383,14 +383,22 @@ void xdp_attachment_setup(struct xdp_attachment_info *info, 


#define DEV_MAP_BULK_SIZE XDP_BULK_QUEUE_SIZE



/* Define the relationship between xdp-rx-metadata kfunc and

 * various other entities:

 * - xdp_rx_metadata enum

 * - kfunc name

 * - xdp_metadata_ops field

 */

#define XDP_METADATA_KFUNC_xxx	\

	XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_TIMESTAMP, \

			   bpf_xdp_metadata_rx_timestamp) \

			   bpf_xdp_metadata_rx_timestamp, \

			   xmo_rx_timestamp) \

	XDP_METADATA_KFUNC(XDP_METADATA_KFUNC_RX_HASH, \

			   bpf_xdp_metadata_rx_hash) \

			   bpf_xdp_metadata_rx_hash, \

			   xmo_rx_hash) \



enum {

#define XDP_METADATA_KFUNC(name, _) name,

enum xdp_rx_metadata {

#define XDP_METADATA_KFUNC(name, _, __) name,

XDP_METADATA_KFUNC_xxx

#undef XDP_METADATA_KFUNC

MAX_XDP_METADATA_KFUNC,

kernel/bpf/offload.c

+5 −4
Original line number Diff line number Diff line
@@ -845,10 +845,11 @@ void *bpf_dev_bound_resolve_kfunc(struct bpf_prog *prog, u32 func_id) 
	if (!ops)

		goto out;



	if (func_id == bpf_xdp_metadata_kfunc_id(XDP_METADATA_KFUNC_RX_TIMESTAMP))

		p = ops->xmo_rx_timestamp;

	else if (func_id == bpf_xdp_metadata_kfunc_id(XDP_METADATA_KFUNC_RX_HASH))

		p = ops->xmo_rx_hash;

#define XDP_METADATA_KFUNC(name, _, xmo) \

	if (func_id == bpf_xdp_metadata_kfunc_id(name)) p = ops->xmo;

	XDP_METADATA_KFUNC_xxx

#undef XDP_METADATA_KFUNC



out:

	up_read(&bpf_devs_lock);

net/core/xdp.c

+2 −2
Original line number Diff line number Diff line
@@ -741,7 +741,7 @@ __bpf_kfunc int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, u32 *hash, 
__diag_pop();



BTF_SET8_START(xdp_metadata_kfunc_ids)

#define XDP_METADATA_KFUNC(_, name) BTF_ID_FLAGS(func, name, KF_TRUSTED_ARGS)

#define XDP_METADATA_KFUNC(_, name, __) BTF_ID_FLAGS(func, name, KF_TRUSTED_ARGS)

XDP_METADATA_KFUNC_xxx

#undef XDP_METADATA_KFUNC

BTF_SET8_END(xdp_metadata_kfunc_ids)
@@ -752,7 +752,7 @@ static const struct btf_kfunc_id_set xdp_metadata_kfunc_set = { 
};



BTF_ID_LIST(xdp_metadata_kfunc_ids_unsorted)

#define XDP_METADATA_KFUNC(name, str) BTF_ID(func, str)

#define XDP_METADATA_KFUNC(name, str, _) BTF_ID(func, str)

XDP_METADATA_KFUNC_xxx

#undef XDP_METADATA_KFUNC