From 1dedc6d8cff41aa6c21939050e7fcbede2aac5cb Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Tue, 18 Apr 2023 14:39:52 +0300 Subject: tc/mqprio: add support for preemptible traffic classes Add support for the "fp" argument in tc-mqprio, which takes an array of letters "E" (for express) or "P" (for preemptible), one per traffic class, and transforms them into TCA_MQPRIO_TC_ENTRY_FP u32 attributes of the TCA_MQPRIO_TC_ENTRY nest. We also dump these new netlink attributes when they come from the kernel. Signed-off-by: Vladimir Oltean Signed-off-by: David Ahern --- man/man8/tc-mqprio.8 | 36 +++++++++++++++++-- tc/q_mqprio.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 132 insertions(+), 3 deletions(-) diff --git a/man/man8/tc-mqprio.8 b/man/man8/tc-mqprio.8 index 3441cb68..724ef906 100644 --- a/man/man8/tc-mqprio.8 +++ b/man/man8/tc-mqprio.8 @@ -30,9 +30,11 @@ dcb|bw_rlimit ] .B min_rate min_rate1 min_rate2 ... ] [ .B max_rate -max_rate1 max_rate2 ... -.B ] - +max_rate1 max_rate2 ... ] +.ti +8 +[ +.B fp +FP0 FP1 FP2 ... ] .SH DESCRIPTION The MQPRIO qdisc is a simple queuing discipline that allows mapping @@ -162,6 +164,34 @@ the argument is set to .B 'bw_rlimit'. +.TP +fp +Selects whether traffic classes are express (deliver packets via the eMAC) or +preemptible (deliver packets via the pMAC), according to IEEE 802.1Q-2018 +clause 6.7.2 Frame preemption. Takes the form of an array (one element per +traffic class) with values being +.B 'E' +(for express) or +.B 'P' +(for preemptible). + +Multiple priorities which map to the same traffic class, as well as multiple +TXQs which map to the same traffic class, must have the same FP attributes. +To interpret the FP as an attribute per priority, the +.B 'map' +argument can be used for translation. To interpret FP as an attribute per TXQ, +the +.B 'queues' +argument can be used for translation. + +Traffic classes are express by default. The argument is supported only with +.B 'hw' +set to 1. Preemptible traffic classes are accepted only if the device has a MAC +Merge layer configurable through +.BR ethtool(8). + +.SH SEE ALSO +.BR ethtool(8) .SH EXAMPLE diff --git a/tc/q_mqprio.c b/tc/q_mqprio.c index 99c43491..7a4417f5 100644 --- a/tc/q_mqprio.c +++ b/tc/q_mqprio.c @@ -23,12 +23,29 @@ static void explain(void) "Usage: ... mqprio [num_tc NUMBER] [map P0 P1 ...]\n" " [queues count1@offset1 count2@offset2 ...] " "[hw 1|0]\n" + " [fp FP0 FP1 FP2 ...]\n" " [mode dcb|channel]\n" " [shaper bw_rlimit SHAPER_PARAMS]\n" "Where: SHAPER_PARAMS := { min_rate MIN_RATE1 MIN_RATE2 ...|\n" " max_rate MAX_RATE1 MAX_RATE2 ... }\n"); } +static void add_tc_entries(struct nlmsghdr *n, __u32 fp[TC_QOPT_MAX_QUEUE], + int num_fp_entries) +{ + struct rtattr *l; + __u32 tc; + + for (tc = 0; tc < num_fp_entries; tc++) { + l = addattr_nest(n, 1024, TCA_MQPRIO_TC_ENTRY | NLA_F_NESTED); + + addattr32(n, 1024, TCA_MQPRIO_TC_ENTRY_INDEX, tc); + addattr32(n, 1024, TCA_MQPRIO_TC_ENTRY_FP, fp[tc]); + + addattr_nest_end(n, l); + } +} + static int mqprio_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct nlmsghdr *n, const char *dev) { @@ -43,7 +60,10 @@ static int mqprio_parse_opt(struct qdisc_util *qu, int argc, __u64 min_rate64[TC_QOPT_MAX_QUEUE] = {0}; __u64 max_rate64[TC_QOPT_MAX_QUEUE] = {0}; __u16 shaper = TC_MQPRIO_SHAPER_DCB; + __u32 fp[TC_QOPT_MAX_QUEUE] = { }; __u16 mode = TC_MQPRIO_MODE_DCB; + bool have_tc_entries = false; + int num_fp_entries = 0; int cnt_off_pairs = 0; struct rtattr *tail; __u32 flags = 0; @@ -93,6 +113,21 @@ static int mqprio_parse_opt(struct qdisc_util *qu, int argc, idx++; cnt_off_pairs++; } + } else if (strcmp(*argv, "fp") == 0) { + while (idx < TC_QOPT_MAX_QUEUE && NEXT_ARG_OK()) { + NEXT_ARG(); + if (strcmp(*argv, "E") == 0) { + fp[idx] = TC_FP_EXPRESS; + } else if (strcmp(*argv, "P") == 0) { + fp[idx] = TC_FP_PREEMPTIBLE; + } else { + PREV_ARG(); + break; + } + num_fp_entries++; + idx++; + } + have_tc_entries = true; } else if (strcmp(*argv, "hw") == 0) { NEXT_ARG(); if (get_u8(&opt.hw, *argv, 10)) { @@ -187,6 +222,9 @@ static int mqprio_parse_opt(struct qdisc_util *qu, int argc, addattr_l(n, 1024, TCA_MQPRIO_SHAPER, &shaper, sizeof(shaper)); + if (have_tc_entries) + add_tc_entries(n, fp, num_fp_entries); + if (flags & TC_MQPRIO_F_MIN_RATE) { struct rtattr *start; @@ -218,6 +256,64 @@ static int mqprio_parse_opt(struct qdisc_util *qu, int argc, return 0; } +static void dump_tc_entry(struct rtattr *rta, __u32 fp[TC_QOPT_MAX_QUEUE], + int *max_tc_fp) +{ + struct rtattr *tb[TCA_MQPRIO_TC_ENTRY_MAX + 1]; + __u32 tc, val = 0; + + parse_rtattr_nested(tb, TCA_MQPRIO_TC_ENTRY_MAX, rta); + + if (!tb[TCA_MQPRIO_TC_ENTRY_INDEX]) { + fprintf(stderr, "Missing tc entry index\n"); + return; + } + + tc = rta_getattr_u32(tb[TCA_MQPRIO_TC_ENTRY_INDEX]); + /* Prevent array out of bounds access */ + if (tc >= TC_QOPT_MAX_QUEUE) { + fprintf(stderr, "Unexpected tc entry index %d\n", tc); + return; + } + + if (tb[TCA_MQPRIO_TC_ENTRY_FP]) { + val = rta_getattr_u32(tb[TCA_MQPRIO_TC_ENTRY_FP]); + fp[tc] = val; + + if (*max_tc_fp < (int)tc) + *max_tc_fp = tc; + } +} + +static void dump_tc_entries(FILE *f, struct rtattr *opt, int len) +{ + __u32 fp[TC_QOPT_MAX_QUEUE] = {}; + int max_tc_fp = -1; + struct rtattr *rta; + int tc; + + for (rta = opt; RTA_OK(rta, len); rta = RTA_NEXT(rta, len)) { + if (rta->rta_type != (TCA_MQPRIO_TC_ENTRY | NLA_F_NESTED)) + continue; + + dump_tc_entry(rta, fp, &max_tc_fp); + } + + if (max_tc_fp >= 0) { + open_json_array(PRINT_ANY, + is_json_context() ? "fp" : "\n fp:"); + for (tc = 0; tc <= max_tc_fp; tc++) { + print_string(PRINT_ANY, NULL, " %s", + fp[tc] == TC_FP_PREEMPTIBLE ? "P" : + fp[tc] == TC_FP_EXPRESS ? "E" : + "?"); + } + close_json_array(PRINT_ANY, ""); + + print_nl(); + } +} + static int mqprio_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt) { int i; @@ -309,7 +405,10 @@ static int mqprio_print_opt(struct qdisc_util *qu, FILE *f, struct rtattr *opt) tc_print_rate(PRINT_ANY, NULL, "%s ", max_rate64[i]); close_json_array(PRINT_ANY, ""); } + + dump_tc_entries(f, RTA_DATA(opt) + RTA_ALIGN(sizeof(*qopt)), len); } + return 0; } -- cgit v1.2.1