selftests: xsk: Disassociate umem size with packets sent

Disassociate the number of packets sent with the number of buffers in
the umem. This so we can loop over the umem to test more things. Set
the size of the umem to be a multiple of 2M. A requirement for huge
pages that are needed in unaligned mode.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210825093722.10219-8-magnus.karlsson@gmail.com

tools/testing/selftests/bpf/xdpxceiver.c

@@ -250,7 +250,7 @@ static void gen_eth_frame(struct xsk_umem_info *umem, u64 addr)
 	memcpy(xsk_umem__get_data(umem->buffer, addr), pkt_data, PKT_SIZE);
 }
 
-static void xsk_configure_umem(struct ifobject *data, void *buffer, int idx)
+static void xsk_configure_umem(struct ifobject *data, void *buffer, u64 size, int idx)
 {
 	struct xsk_umem_config cfg = {
 		.fill_size = XSK_RING_PROD__DEFAULT_NUM_DESCS,
@@ -259,7 +259,6 @@ static void xsk_configure_umem(struct ifobject *data, void *buffer, int idx)
 		.frame_headroom = frame_headroom,
 		.flags = XSK_UMEM__DEFAULT_FLAGS
 	};
-	int size = num_frames * XSK_UMEM__DEFAULT_FRAME_SIZE;
 	struct xsk_umem_info *umem;
 	int ret;
 
@@ -722,22 +721,23 @@ static void worker_pkt_validate(void)
 
 static void thread_common_ops(struct ifobject *ifobject, void *bufs)
 {
-	int umem_sz = num_frames * XSK_UMEM__DEFAULT_FRAME_SIZE;
+	u64 umem_sz = num_frames * XSK_UMEM__DEFAULT_FRAME_SIZE;
+	int mmap_flags = MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE;
+	size_t mmap_sz = umem_sz;
 	int ctr = 0;
 	int ret;
 
 	ifobject->ns_fd = switch_namespace(ifobject->nsname);
 
 	if (test_type == TEST_TYPE_BPF_RES)
-		umem_sz *= 2;
+		mmap_sz *= 2;
 
-	bufs = mmap(NULL, umem_sz,
-		    PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	bufs = mmap(NULL, mmap_sz, PROT_READ | PROT_WRITE, mmap_flags, -1, 0);
 	if (bufs == MAP_FAILED)
 		exit_with_error(errno);
 
 	while (ctr++ < SOCK_RECONF_CTR) {
-		xsk_configure_umem(ifobject, bufs, 0);
+		xsk_configure_umem(ifobject, bufs, umem_sz, 0);
 		ifobject->umem = ifobject->umem_arr[0];
 		ret = xsk_configure_socket(ifobject, 0);
 		if (!ret)
@@ -753,7 +753,7 @@ static void thread_common_ops(struct ifobject *ifobject, void *bufs)
 	ifobject->xsk = ifobject->xsk_arr[0];
 
 	if (test_type == TEST_TYPE_BPF_RES) {
-		xsk_configure_umem(ifobject, (u8 *)bufs + (umem_sz / 2), 1);
+		xsk_configure_umem(ifobject, (u8 *)bufs + umem_sz, umem_sz, 1);
 		ifobject->umem = ifobject->umem_arr[1];
 		ret = xsk_configure_socket(ifobject, 1);
 	}
@@ -1094,8 +1094,6 @@ int main(int argc, char **argv)
 
 	parse_command_line(argc, argv);
 
-	num_frames = ++opt_pkt_count;
-
 	init_iface(ifdict[0], MAC1, MAC2, IP1, IP2, UDP_PORT1, UDP_PORT2, tx);
 	init_iface(ifdict[1], MAC2, MAC1, IP2, IP1, UDP_PORT2, UDP_PORT1, rx);
 

tools/testing/selftests/bpf/xdpxceiver.h

@@ -70,7 +70,7 @@ enum STAT_TEST_TYPES {
 
 static int configured_mode = TEST_MODE_UNCONFIGURED;
 static u8 debug_pkt_dump;
-static u32 num_frames;
+static u32 num_frames = DEFAULT_PKT_CNT / 4;
 static bool second_step;
 static int test_type;