This patch adds Launch Time hw offload request to xdp_hw_metadata. User can configure the delta of HW launch time to HW RX-time by using "-l" argument. The default delta is set to 0.1 second.
This patch is tested with stmmac on Intel Tiger Lake platform. Refer to result below, the delta between pre-determined launch time and actual HW transmit complete time is around 24 us.
$ sudo ./xdp_hw_metadata eth0 ... xsk_ring_cons__peek: 1 0x55e577c3a7a8: rx_desc[0]->addr=80100 addr=80100 comp_addr=80100 EoP No rx_hash err=-95 HW RX-time: 1677762523393813392 (sec:1677762523.3938) delta to User RX-time sec:0.0003 (259.290 usec) XDP RX-time: 1677762523394050576 (sec:1677762523.3941) delta to User RX-time sec:0.0000 (22.106 usec) 0x55e577c3a7a8: ping-pong with csum=5619 (want 8626) csum_start=34 csum_offset=6 HW RX-time: 1677762523393813392 (sec:1677762523.3938) delta to HW Launch-time sec:0.1000 (100000.000 usec) 0x55e577c3a7a8: complete tx idx=0 addr=18 HW Launch-time: 1677762523493813392 (sec:1677762523.4938) delta to HW TX-complete-time sec:0.0000 (24.181 usec) HW TX-complete-time: 1677762523493837573 (sec:1677762523.4938) delta to User TX-complete-time sec:0.0007 (737.636 usec) XDP RX-time: 1677762523394050576 (sec:1677762523.3941) delta to User TX-complete-time sec:0.1005 (100524.633 usec) HW RX-time: 1677762523393813392 (sec:1677762523.3938) delta to HW TX-complete-time sec:0.1000 (100024.181 usec) 0x55e577c3a7a8: complete rx idx=128 addr=80100
$ sudo ./xdp_hw_metadata eth0 -l 10000000 ... poll: 1 (0) skip=17 fail=0 redir=17 xsk_ring_cons__peek: 1 0x558336d397a8: rx_desc[15]->addr=9e100 addr=9e100 comp_addr=9e100 EoP No rx_hash err=-95 HW RX-time: 1677762699254666655 (sec:1677762699.2547) delta to User RX-time sec:0.0003 (256.928 usec) XDP RX-time: 1677762699254901232 (sec:1677762699.2549) delta to User RX-time sec:0.0000 (22.351 usec) 0x558336d397a8: ping-pong with csum=5619 (want 8626) csum_start=34 csum_offset=6 HW RX-time: 1677762699254666655 (sec:1677762699.2547) delta to HW Launch-time sec:0.0100 (10000.000 usec) 0x558336d397a8: complete tx idx=15 addr=f018 HW Launch-time: 1677762699264666655 (sec:1677762699.2647) delta to HW TX-complete-time sec:0.0000 (24.307 usec) HW TX-complete-time: 1677762699264690962 (sec:1677762699.2647) delta to User TX-complete-time sec:0.0003 (309.901 usec) XDP RX-time: 1677762699254901232 (sec:1677762699.2549) delta to User TX-complete-time sec:0.0101 (10099.631 usec) HW RX-time: 1677762699254666655 (sec:1677762699.2547) delta to HW TX-complete-time sec:0.0100 (10024.307 usec) 0x558336d397a8: complete rx idx=143 addr=9e100
Signed-off-by: Song Yoong Siang yoong.siang.song@intel.com --- tools/testing/selftests/bpf/xdp_hw_metadata.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/xdp_hw_metadata.c b/tools/testing/selftests/bpf/xdp_hw_metadata.c index 3291625ba4fb..3e238bb310b7 100644 --- a/tools/testing/selftests/bpf/xdp_hw_metadata.c +++ b/tools/testing/selftests/bpf/xdp_hw_metadata.c @@ -13,6 +13,7 @@ * - UDP 9091 packets trigger TX reply * - TX HW timestamp is requested and reported back upon completion * - TX checksum is requested + * - HW launch time is set for transmission */
#include <test_progs.h> @@ -61,6 +62,8 @@ int rxq; bool skip_tx; __u64 last_hw_rx_timestamp; __u64 last_xdp_rx_timestamp; +__u64 last_launch_time; +__u64 launch_time_delta_to_hw_rx_timestamp = 100000000; /* 0.1 second */
void test__fail(void) { /* for network_helpers.c */ }
@@ -274,6 +277,8 @@ static bool complete_tx(struct xsk *xsk, clockid_t clock_id) if (meta->completion.tx_timestamp) { __u64 ref_tstamp = gettime(clock_id);
+ print_tstamp_delta("HW Launch-time", "HW TX-complete-time", + last_launch_time, meta->completion.tx_timestamp); print_tstamp_delta("HW TX-complete-time", "User TX-complete-time", meta->completion.tx_timestamp, ref_tstamp); print_tstamp_delta("XDP RX-time", "User TX-complete-time", @@ -371,6 +376,14 @@ static void ping_pong(struct xsk *xsk, void *rx_packet, clockid_t clock_id) xsk, ntohs(udph->check), ntohs(want_csum), meta->request.csum_start, meta->request.csum_offset);
+ /* Set the value of launch time */ + meta->flags |= XDP_TXMD_FLAGS_LAUNCH_TIME; + meta->request.launch_time = last_hw_rx_timestamp + + launch_time_delta_to_hw_rx_timestamp; + last_launch_time = meta->request.launch_time; + print_tstamp_delta("HW RX-time", "HW Launch-time", last_hw_rx_timestamp, + meta->request.launch_time); + memcpy(data, rx_packet, len); /* don't share umem chunk for simplicity */ tx_desc->options |= XDP_TX_METADATA; tx_desc->len = len; @@ -595,6 +608,7 @@ static void print_usage(void) " -h Display this help and exit\n\n" " -m Enable multi-buffer XDP for larger MTU\n" " -r Don't generate AF_XDP reply (rx metadata only)\n" + " -l Delta of HW Launch-time to HW RX-time in ns (default: 0.1s)\n" "Generate test packets on the other machine with:\n" " echo -n xdp | nc -u -q1 <dst_ip> 9091\n";
@@ -605,7 +619,7 @@ static void read_args(int argc, char *argv[]) { int opt;
- while ((opt = getopt(argc, argv, "chmr")) != -1) { + while ((opt = getopt(argc, argv, "chmrl:")) != -1) { switch (opt) { case 'c': bind_flags &= ~XDP_USE_NEED_WAKEUP; @@ -621,6 +635,9 @@ static void read_args(int argc, char *argv[]) case 'r': skip_tx = true; break; + case 'l': + launch_time_delta_to_hw_rx_timestamp = atoll(optarg); + break; case '?': if (isprint(optopt)) fprintf(stderr, "Unknown option: -%c\n", optopt);