[PATCH bpf-next 3/3] selftests/bpf: Add launch time to xdp_hw_metadata
From: Song Yoong Siang
Date: Thu Nov 30 2023 - 11:22:19 EST
This patch adds launch time support to xdp_hw_metadata. User can configure
the delta of HW launch time to HW RX-time by using "-l" argument.
This patch is tested with stmmac on Intel Tiger Lake platform. Refer to
result below, the delta between pre-determined launch time and actual
transmit time is around 24 us.
$ sudo ./xdp_hw_metadata enp0s30f4
...
xsk_ring_cons__peek: 1
0x55fcb80ce7a8: rx_desc[0]->addr=80100 addr=80100 comp_addr=80100 EoP
No rx_hash err=-95
HW RX-time: 1677764507059055964 (sec:1677764507.0591) delta to User RX-time sec:0.0002 (237.548 usec)
XDP RX-time: 1677764507059280741 (sec:1677764507.0593) delta to User RX-time sec:0.0000 (12.771 usec)
0x55fcb80ce7a8: ping-pong with csum=5619 (want 8626) csum_start=34 csum_offset=6
HW RX-time: 1677764507059055964 (sec:1677764507.0591) delta to HW Launch-time sec:1.0000 (1000000.000 usec)
0x55fcb80ce7a8: complete tx idx=0 addr=18
HW Launch-time: 1677764508059055964 (sec:1677764508.0591) delta to HW TX-complete-time sec:0.0000 (24.235 usec)
HW TX-complete-time: 1677764508059080199 (sec:1677764508.0591) delta to User TX-complete-time sec:0.0054 (5423.263 usec)
XDP RX-time: 1677764507059280741 (sec:1677764507.0593) delta to User TX-complete-time sec:1.0052 (1005222.721 usec)
HW RX-time: 1677764507059055964 (sec:1677764507.0591) delta to HW TX-complete-time sec:1.0000 (1000024.235 usec)
0x55fcb80ce7a8: complete rx idx=128 addr=80100
$ sudo ./xdp_hw_metadata enp0s30f4 -l 10000000
...
xsk_ring_cons__peek: 1
0x5626d54de7a8: rx_desc[0]->addr=80100 addr=80100 comp_addr=80100 EoP
No rx_hash err=-95
HW RX-time: 1677764655807717783 (sec:1677764655.8077) delta to User RX-time sec:0.0002 (240.571 usec)
XDP RX-time: 1677764655807942983 (sec:1677764655.8079) delta to User RX-time sec:0.0000 (15.371 usec)
0x5626d54de7a8: ping-pong with csum=5619 (want 8626) csum_start=34 csum_offset=6
HW RX-time: 1677764655807717783 (sec:1677764655.8077) delta to HW Launch-time sec:0.0100 (10000.000 usec)
0x5626d54de7a8: complete tx idx=0 addr=18
HW Launch-time: 1677764655817717783 (sec:1677764655.8177) delta to HW TX-complete-time sec:0.0000 (23.965 usec)
HW TX-complete-time: 1677764655817741748 (sec:1677764655.8177) delta to User TX-complete-time sec:0.0003 (291.792 usec)
XDP RX-time: 1677764655807942983 (sec:1677764655.8079) delta to User TX-complete-time sec:0.0101 (10090.557 usec)
HW RX-time: 1677764655807717783 (sec:1677764655.8077) delta to HW TX-complete-time sec:0.0100 (10023.965 usec)
0x5626d54de7a8: complete rx idx=128 addr=80100
Signed-off-by: Song Yoong Siang <yoong.siang.song@xxxxxxxxx>
---
tools/testing/selftests/bpf/xdp_hw_metadata.c | 18 +++++++++++++++++-
1 file changed, 17 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..ff1b2e5b0fce 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_offset = 1000000000; /* 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 +376,13 @@ 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 launch time at launch_time_offset ns later than HW Rx-time */
+ meta->flags |= XDP_TXMD_FLAGS_LAUNCH_TIME;
+ last_launch_time = last_hw_rx_timestamp + launch_time_offset;
+ meta->request.launch_time = last_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 +607,7 @@ 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: 1s)\n"
"Generate test packets on the other machine with:\n"
" echo -n xdp | nc -u -q1 <dst_ip> 9091\n";
@@ -605,7 +618,7 @@ 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 +634,9 @@ static void read_args(int argc, char *argv[])
case 'r':
skip_tx = true;
break;
+ case 'l':
+ launch_time_offset = atoll(optarg);
+ break;
case '?':
if (isprint(optopt))
fprintf(stderr, "Unknown option: -%c\n", optopt);
--
2.34.1