[Intel-wired-lan] [PATCH bpf-next v4 08/11] samples/bpf: add unaligned chunks mode support to xdpsock

[Kevin Laatz]

This patch adds support for the unaligned chunks mode. The addition of the
unaligned chunks option will allow users to run the application with more
relaxed chunk placement in the XDP umem.

Unaligned chunks mode can be used with the '-u' or '--unaligned' command
line options.

Signed-off-by: Kevin Laatz <kevin.laatz at intel.com>
Signed-off-by: Ciara Loftus <ciara.loftus at intel.com>

---
v4:
  - updated help text for -f
  - use new chunk flag define
---
 samples/bpf/xdpsock_user.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c
index 93eaaf7239b2..756b00eb1afe 100644
--- a/samples/bpf/xdpsock_user.c
+++ b/samples/bpf/xdpsock_user.c
@@ -51,6 +51,7 @@
 
 typedef __u64 u64;
 typedef __u32 u32;
+typedef __u16 u16;
 
 static unsigned long prev_time;
 
@@ -67,6 +68,8 @@ static int opt_ifindex;
 static int opt_queue;
 static int opt_poll;
 static int opt_interval = 1;
+static u16 opt_umem_flags;
+static int opt_unaligned_chunks;
 static u32 opt_xdp_bind_flags;
 static int opt_xsk_frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE;
 static __u32 prog_id;
@@ -282,7 +285,9 @@ static struct xsk_umem_info *xsk_configure_umem(void *buffer, u64 size)
 		.comp_size = XSK_RING_CONS__DEFAULT_NUM_DESCS,
 		.frame_size = opt_xsk_frame_size,
 		.frame_headroom = XSK_UMEM__DEFAULT_FRAME_HEADROOM,
+		.flags = opt_umem_flags
 	};
+
 	int ret;
 
 	umem = calloc(1, sizeof(*umem));
@@ -291,6 +296,7 @@ static struct xsk_umem_info *xsk_configure_umem(void *buffer, u64 size)
 
 	ret = xsk_umem__create(&umem->umem, buffer, size, &umem->fq, &umem->cq,
 			       &cfg);
+
 	if (ret)
 		exit_with_error(-ret);
 
@@ -352,6 +358,7 @@ static struct option long_options[] = {
 	{"zero-copy", no_argument, 0, 'z'},
 	{"copy", no_argument, 0, 'c'},
 	{"frame-size", required_argument, 0, 'f'},
+	{"unaligned", no_argument, 0, 'u'},
 	{0, 0, 0, 0}
 };
 
@@ -371,7 +378,8 @@ static void usage(const char *prog)
 		"  -n, --interval=n	Specify statistics update interval (default 1 sec).\n"
 		"  -z, --zero-copy      Force zero-copy mode.\n"
 		"  -c, --copy           Force copy mode.\n"
-		"  -f, --frame-size=n   Set the frame size (must be a power of two, default is %d).\n"
+		"  -f, --frame-size=n   Set the frame size (must be a power of two in aligned mode, default is %d).\n"
+		"  -u, --unaligned	Enable unaligned chunk placement\n"
 		"\n";
 	fprintf(stderr, str, prog, XSK_UMEM__DEFAULT_FRAME_SIZE);
 	exit(EXIT_FAILURE);
@@ -384,7 +392,7 @@ static void parse_command_line(int argc, char **argv)
 	opterr = 0;
 
 	for (;;) {
-		c = getopt_long(argc, argv, "Frtli:q:psSNn:czf:", long_options,
+		c = getopt_long(argc, argv, "Frtli:q:psSNn:czf:u", long_options,
 				&option_index);
 		if (c == -1)
 			break;
@@ -424,12 +432,17 @@ static void parse_command_line(int argc, char **argv)
 		case 'c':
 			opt_xdp_bind_flags |= XDP_COPY;
 			break;
+		case 'u':
+			opt_umem_flags |= XDP_UMEM_UNALIGNED_CHUNK_FLAG;
+			opt_unaligned_chunks = 1;
+			break;
 		case 'F':
 			opt_xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
 			break;
 		case 'f':
 			opt_xsk_frame_size = atoi(optarg);
 			break;
+
 		default:
 			usage(basename(argv[0]));
 		}
@@ -442,7 +455,8 @@ static void parse_command_line(int argc, char **argv)
 		usage(basename(argv[0]));
 	}
 
-	if (opt_xsk_frame_size & (opt_xsk_frame_size - 1)) {
+	if ((opt_xsk_frame_size & (opt_xsk_frame_size - 1)) &&
+	    !opt_unaligned_chunks) {
 		fprintf(stderr, "--frame-size=%d is not a power of two\n",
 			opt_xsk_frame_size);
 		usage(basename(argv[0]));
-- 
2.17.1