Re: [PATCH bpf-next v5 17/17] selftests/bpf: Simple program to dump XDP RX metadata

Martin KaFai Lau
2022-12-23T00:53:17Z

On 12/20/22 2:20 PM, Stanislav Fomichev wrote:
> To be used for verification of driver implementations. Note that
> the skb path is gone from the series, but I'm still keeping the
> implementation for any possible future work.
>
> $ xdp_hw_metadata <ifname>
>
> On the other machine:
>
> $ echo -n xdp | nc -u -q1 <target> 9091 # for AF_XDP
> $ echo -n skb | nc -u -q1 <target> 9092 # for skb
>
> Sample output:
>
> # xdp
> xsk_ring_cons__peek: 1
> 0x19f9090: rx_desc[0]->addr=100000000008000 addr=8100 comp_addr=8000
> rx_timestamp_supported: 1
> rx_timestamp: 1667850075063948829
> 0x19f9090: complete idx=8 addr=8000
>
> # skb
> found skb hwtstamp = 1668314052.854274681
>
> Decoding:
> # xdp
> rx_timestamp=1667850075.063948829
>
> $ date -d @1667850075
> Mon Nov 7 11:41:15 AM PST 2022
> $ date
> Mon Nov 7 11:42:05 AM PST 2022
>
> # skb
> $ date -d @1668314052
> Sat Nov 12 08:34:12 PM PST 2022
> $ date
> Sat Nov 12 08:37:06 PM PST 2022
>
> Cc: John Fastabend <john.fastabend@gmail.com>
> Cc: David Ahern <dsahern@gmail.com>
> Cc: Martin KaFai Lau <martin.lau@linux.dev>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Willem de Bruijn <willemb@google.com>
> Cc: Jesper Dangaard Brouer <brouer@redhat.com>
> Cc: Anatoly Burakov <anatoly.burakov@intel.com>
> Cc: Alexander Lobakin <alexandr.lobakin@intel.com>
> Cc: Magnus Karlsson <magnus.karlsson@gmail.com>
> Cc: Maryam Tahhan <mtahhan@redhat.com>
> Cc: xdp-hints@xdp-project.net
> Cc: netdev@vger.kernel.org
> Signed-off-by: Stanislav Fomichev <sdf@google.com>
> ---
> tools/testing/selftests/bpf/.gitignore | 1 +
> tools/testing/selftests/bpf/Makefile | 6 +-
> .../selftests/bpf/progs/xdp_hw_metadata.c | 81 ++++
> tools/testing/selftests/bpf/xdp_hw_metadata.c | 405 ++++++++++++++++++
> 4 files changed, 492 insertions(+), 1 deletion(-)
> create mode 100644 tools/testing/selftests/bpf/progs/xdp_hw_metadata.c
> create mode 100644 tools/testing/selftests/bpf/xdp_hw_metadata.c
>
> diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore
> index 07d2d0a8c5cb..01e3baeefd4f 100644
> --- a/tools/testing/selftests/bpf/.gitignore
> +++ b/tools/testing/selftests/bpf/.gitignore
> @@ -46,3 +46,4 @@ test_cpp
> xskxceiver
> xdp_redirect_multi
> xdp_synproxy
> +xdp_hw_metadata
> diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
> index e6cbc04a7920..b7d5d3aa554e 100644
> --- a/tools/testing/selftests/bpf/Makefile
> +++ b/tools/testing/selftests/bpf/Makefile
> @@ -83,7 +83,7 @@ TEST_PROGS_EXTENDED := with_addr.sh \
> TEST_GEN_PROGS_EXTENDED = test_sock_addr test_skb_cgroup_id_user \
> flow_dissector_load test_flow_dissector test_tcp_check_syncookie_user \
> test_lirc_mode2_user xdping test_cpp runqslower bench bpf_testmod.ko \
> - xskxceiver xdp_redirect_multi xdp_synproxy veristat
> + xskxceiver xdp_redirect_multi xdp_synproxy veristat xdp_hw_metadata
>
> TEST_CUSTOM_PROGS = $(OUTPUT)/urandom_read $(OUTPUT)/sign-file
> TEST_GEN_FILES += liburandom_read.so
> @@ -241,6 +241,9 @@ $(OUTPUT)/test_maps: $(TESTING_HELPERS)
> $(OUTPUT)/test_verifier: $(TESTING_HELPERS) $(CAP_HELPERS)
> $(OUTPUT)/xsk.o: $(BPFOBJ)
> $(OUTPUT)/xskxceiver: $(OUTPUT)/xsk.o
> +$(OUTPUT)/xdp_hw_metadata: $(OUTPUT)/xsk.o $(OUTPUT)/xdp_hw_metadata.skel.h
> +$(OUTPUT)/xdp_hw_metadata: $(OUTPUT)/network_helpers.o
> +$(OUTPUT)/xdp_hw_metadata: LDFLAGS += -static

This test binary fails to build for llvm. gcc looks fine though. The CI tests
cannot be run on this set because of this. Please take a look:

https://github.com/kernel-patches/bpf/actions/runs/3745257032/jobs/6359527599#step:11:2202

I only have minor comments on the set. Looking forward to v6.