xdp-bench: Add option to use xdp_load_bytes() helper when parsing IP

This adds an option to xdp-bench to use the xdp_load_bytes() helper when parsing the IP header (for the basic options). This can be used to benchmark the overhead of xdp_load_bytes() relative to DPA. Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
xdp-project · Jun 8, 2023 · fcb9822 · fcb9822
1 parent b43595e
commit fcb9822
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Showing 5 changed files with 53 additions and 2 deletions.
diff --git a/xdp-bench/tests/test-xdp-bench.sh b/xdp-bench/tests/test-xdp-bench.sh
@@ -10,6 +10,7 @@ test_basic()
     check_run $XDP_BENCH $action $NS -vv
     check_run $XDP_BENCH $action $NS -p read-data -vv
     check_run $XDP_BENCH $action $NS -p parse-ip -vv
+    check_run $XDP_BENCH $action $NS -p parse-ip -l -vv
     check_run $XDP_BENCH $action $NS -p swap-macs -vv
     check_run $XDP_BENCH $action $NS -m skb -vv
     check_run $XDP_BENCH $action $NS -e -vv

diff --git a/xdp-bench/xdp-bench.c b/xdp-bench/xdp-bench.c
@@ -70,6 +70,9 @@ struct prog_option basic_options[] = {
 	DEFINE_OPTION("rxq-stats", OPT_BOOL, struct basic_opts, rxq_stats,
 		      .short_opt = 'r',
 		      .help = "Collect per-RXQ drop statistics"),
+	DEFINE_OPTION("load-bytes", OPT_BOOL, struct basic_opts, load_bytes,
+		      .short_opt = 'l',
+		      .help = "Use xdp_load_bytes() helper when parsing IP header"),
 	DEFINE_OPTION("interval", OPT_U32, struct basic_opts, interval,
 		      .short_opt = 'i',
 		      .metavar = "<seconds>",

diff --git a/xdp-bench/xdp-bench.h b/xdp-bench/xdp-bench.h
@@ -21,6 +21,7 @@ int do_redirect_devmap_multi(const void *cfg, const char *pin_root_path);
 struct basic_opts {
 	bool extended;
 	bool rxq_stats;
+	bool load_bytes;
 	__u32 interval;
 	enum xdp_attach_mode mode;
 	enum basic_program_mode program_mode;

diff --git a/xdp-bench/xdp_basic.bpf.c b/xdp-bench/xdp_basic.bpf.c
@@ -18,10 +18,50 @@
 
 #include "xdp_basic.shared.h"
 
+#ifndef HAVE_LIBBPF_BPF_PROGRAM__TYPE
+static long (*bpf_xdp_load_bytes)(struct xdp_md *xdp_md, __u32 offset, void *buf, __u32 len) = (void *) 189;
+#endif
+
 const volatile enum basic_program_mode prog_mode = BASIC_NO_TOUCH;
 const volatile bool rxq_stats = 0;
+const volatile bool xdp_load_bytes = 0;
 const volatile enum xdp_action action = XDP_DROP;
 
+static int parse_ip_header_load(struct xdp_md *ctx)
+{
+	int eth_type, ip_type, err, offset = 0;
+	struct ipv6hdr ipv6hdr;
+	struct iphdr iphdr;
+	struct ethhdr eth;
+
+	err = bpf_xdp_load_bytes(ctx, offset, &eth, sizeof(eth));
+	if (err)
+		return err;
+
+	eth_type = eth.h_proto;
+	offset = sizeof(eth);
+
+	if (eth_type == bpf_htons(ETH_P_IP)) {
+		err = bpf_xdp_load_bytes(ctx, offset, &iphdr, sizeof(iphdr));
+		if (err)
+			return err;
+
+		ip_type = iphdr.protocol;
+		if (ip_type < 0)
+			return ip_type;
+	} else if (eth_type == bpf_htons(ETH_P_IPV6)) {
+		err = bpf_xdp_load_bytes(ctx, offset, &ipv6hdr, sizeof(ipv6hdr));
+		if (err)
+			return err;
+
+		ip_type = ipv6hdr.nexthdr;
+		if (ip_type < 0)
+			return ip_type;
+	}
+
+	return 0;
+}
+
 static int parse_ip_header(struct xdp_md *ctx)
 {
 	void *data_end = (void *)(long)ctx->data_end;
@@ -82,8 +122,13 @@ int xdp_basic_prog(struct xdp_md *ctx)
 			return XDP_ABORTED;
 		break;
 	case BASIC_PARSE_IPHDR:
-		if (parse_ip_header(ctx))
-			return XDP_ABORTED;
+		if (xdp_load_bytes) {
+			if (parse_ip_header_load(ctx))
+				return XDP_ABORTED;
+		} else {
+			if (parse_ip_header(ctx))
+				return XDP_ABORTED;
+		}
 		break;
 	case BASIC_SWAP_MACS:
 		swap_src_dst_mac(data);

diff --git a/xdp-bench/xdp_basic.c b/xdp-bench/xdp_basic.c
@@ -66,6 +66,7 @@ static int do_basic(const struct basic_opts *opt, enum xdp_action action)
 		mask |= SAMPLE_DROP_OK;
 
 	skel->rodata->prog_mode = opt->program_mode;
+	skel->rodata->xdp_load_bytes = opt->load_bytes;
 	if (opt->rxq_stats) {
 		skel->rodata->rxq_stats = true;
 		mask |= SAMPLE_RXQ_STATS;