> -----Original Message-----
> From: Vladimir Vdovin <[email protected]>
> Sent: Wednesday, July 8, 2026 10:34 PM
> To: Lorenzo Bianconi <[email protected]>; Donald Hunter
> <[email protected]>; Jakub Kicinski <[email protected]>; David S .
> Miller <[email protected]>; Eric Dumazet <[email protected]>;
> Paolo Abeni <[email protected]>; Simon Horman <[email protected]>;
> Alexei Starovoitov <[email protected]>; Daniel Borkmann
> <[email protected]>; Jesper Dangaard Brouer <[email protected]>; John
> Fastabend <[email protected]>; Stanislav Fomichev
> <[email protected]>; Andrew Lunn <[email protected]>; Nguyen,
> Anthony L <[email protected]>; Kitszel, Przemyslaw
> <[email protected]>; Lobakin, Aleksander
> <[email protected]>; Andrii Nakryiko <[email protected]>;
> Martin KaFai Lau <[email protected]>; Eduard Zingerman
> <[email protected]>; Song Liu <[email protected]>; Yonghong Song
> <[email protected]>; KP Singh <[email protected]>; Hao Luo
> <[email protected]>; Jiri Olsa <[email protected]>; Shuah Khan
> <[email protected]>; Fijalkowski, Maciej <[email protected]>
> Cc: Jakub Sitnicki <[email protected]>; Loktionov, Aleksandr
> <[email protected]>; [email protected];
> [email protected]; [email protected]; linux-
> [email protected]; Vladimir Vdovin <[email protected]>
> Subject: [PATCH bpf-next v4 5/6] selftests/bpf: Add
> bpf_xdp_metadata_rx_checksum support to xdp_hw_metadat prog
>
> From: Lorenzo Bianconi <[email protected]>
>
> Introduce the capability to dump HW rx checksum in xdp_hw_metadata
> program via bpf_xdp_metadata_rx_checksum() kfunc.
>
> Signed-off-by: Lorenzo Bianconi <[email protected]>
> Signed-off-by: Vladimir Vdovin <[email protected]>
> ---
> .../selftests/bpf/progs/xdp_hw_metadata.c | 7 +++++
> tools/testing/selftests/bpf/xdp_hw_metadata.c | 31
> +++++++++++++++++++
> tools/testing/selftests/bpf/xdp_metadata.h | 12 ++++---
> 3 files changed, 46 insertions(+), 4 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
> b/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
> index 330ece2eabdb..5eeadb7e27cf 100644
> --- a/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
> +++ b/tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
> @@ -110,6 +110,13 @@ int rx(struct xdp_md *ctx)
> else
> meta->hint_valid |= XDP_META_FIELD_VLAN_TAG;
>
> + err = bpf_xdp_metadata_rx_checksum(ctx, &meta->ip_summed,
> + &meta->cksum, &meta-
> >cksum_level);
> + if (err)
> + meta->rx_cksum_err = err;
> + else
> + meta->hint_valid |= XDP_META_FIELD_CHECKSUM;
> +
> __sync_add_and_fetch(&pkts_redir, 1);
> return bpf_redirect_map(&xsk, ctx->rx_queue_index, XDP_PASS);
> } diff --git a/tools/testing/selftests/bpf/xdp_hw_metadata.c
> b/tools/testing/selftests/bpf/xdp_hw_metadata.c
> index 6db3b5555a22..c63a70a54075 100644
> --- a/tools/testing/selftests/bpf/xdp_hw_metadata.c
> +++ b/tools/testing/selftests/bpf/xdp_hw_metadata.c
> @@ -8,6 +8,7 @@
> * - Metadata verified:
> * - rx_timestamp
> * - rx_hash
> + * - rx_checksum
> *
> * TX:
> * - UDP 9091 packets trigger TX reply
> @@ -219,6 +220,30 @@ static void print_vlan_tci(__u16 tag)
> printf("PCP=%u, DEI=%d, VID=0x%X\n", pcp, dei, vlan_id); }
>
> +static void print_rx_cksum(__u8 ip_summed, __u32 cksum, __u8
> +cksum_level) {
> + const char *cksum_str;
> +
> + switch (ip_summed) {
> + case XDP_CHECKSUM_COMPLETE | XDP_CHECKSUM_UNNECESSARY:
> + cksum_str = "CHECKSUM_COMPLETE,CHECKSUM_UNNECESSARY";
> + break;
> + case XDP_CHECKSUM_UNNECESSARY:
> + cksum_str = "CHECKSUM_UNNECESSARY";
> + break;
> + case XDP_CHECKSUM_COMPLETE:
> + cksum_str = "CHECKSUM_COMPLETE";
> + break;
> + case XDP_CHECKSUM_NONE:
> + default:
> + cksum_str = "CHECKSUM_NONE";
> + break;
> + }
> +
> + printf("rx-cksum: %s, csum=0x%x, cksum_level=0x%x\n",
> + cksum_str, cksum, cksum_level); }
> +
> static void verify_xdp_metadata(void *data, clockid_t clock_id) {
> struct xdp_meta *meta;
> @@ -254,6 +279,12 @@ static void verify_xdp_metadata(void *data,
> clockid_t clock_id)
> printf("No rx_vlan_tci or rx_vlan_proto, err=%d\n",
> meta->rx_vlan_tag_err);
> }
> +
> + if (meta->hint_valid & XDP_META_FIELD_CHECKSUM)
> + print_rx_cksum(meta->ip_summed, meta->cksum,
> + meta->cksum_level);
> + else
> + printf("No rx_cksum, err=%d\n", meta->rx_cksum_err);
> }
>
> static void verify_skb_metadata(int fd) diff --git
> a/tools/testing/selftests/bpf/xdp_metadata.h
> b/tools/testing/selftests/bpf/xdp_metadata.h
> index bca09b94af26..f864d4a8bd8c 100644
> --- a/tools/testing/selftests/bpf/xdp_metadata.h
> +++ b/tools/testing/selftests/bpf/xdp_metadata.h
> @@ -28,6 +28,7 @@ enum xdp_meta_field {
> XDP_META_FIELD_TS = BIT(0),
> XDP_META_FIELD_RSS = BIT(1),
> XDP_META_FIELD_VLAN_TAG = BIT(2),
> + XDP_META_FIELD_CHECKSUM = BIT(3),
> };
>
> #define XDP_CHECKSUM_NONE BIT(0)
> @@ -52,10 +53,13 @@ struct xdp_meta {
> };
> __s32 rx_vlan_tag_err;
> };
> - struct {
> - __u32 ip_summed;
> - __u32 cksum;
> - __u8 cksum_level;
> + union {
> + struct {
> + __u32 ip_summed;
> + __u32 cksum;
> + __u8 cksum_level;
> + };
> + __s32 rx_cksum_err;
> };
> enum xdp_meta_field hint_valid;
> };
> --
> 2.47.0
Reviewed-by: Aleksandr Loktionov <[email protected]>
