selftests/xsk: populate fill ring based on frags needed

Populate the fill ring based on the number of frags a packet
needs. With multi-buffer support, a packet might require more than a
single fragment/buffer, so the function xsk_populate_fill_ring() needs
to consider how many buffers a packet will consume, and put that many
buffers on the fill ring for each packet it should receive. As we are
still not sending any multi-buffer packets, the function will only
produce one buffer per packet at the moment.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/r/20230516103109.3066-9-magnus.karlsson@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/xsk.h b/tools/testing/selftests/bpf/xsk.h
index 04ed8b5447129d63fcf6adf9063a7be0789fe5e7..8da8d557768b4414e4d66a7944d278f1e417d8e3 100644 (file)
--- a/tools/testing/selftests/bpf/xsk.h
+++ b/tools/testing/selftests/bpf/xsk.h
@@ -134,6 +134,11 @@ static inline void xsk_ring_prod__submit(struct xsk_ring_prod *prod, __u32 nb)
        __atomic_store_n(prod->producer, *prod->producer + nb, __ATOMIC_RELEASE);
 }
 
+static inline void xsk_ring_prod__cancel(struct xsk_ring_prod *prod, __u32 nb)
+{
+       prod->cached_prod -= nb;
+}
+
 static inline __u32 xsk_ring_cons__peek(struct xsk_ring_cons *cons, __u32 nb, __u32 *idx)
 {
        __u32 entries = xsk_cons_nb_avail(cons, nb);

diff --git a/tools/testing/selftests/bpf/xskxceiver.c b/tools/testing/selftests/bpf/xskxceiver.c
index f0d929cb730a0b3057d2f28600c6fd963f2071de..c54f25dcf13404fff1e000b1d775691e1f26f9e9 100644 (file)
--- a/tools/testing/selftests/bpf/xskxceiver.c
+++ b/tools/testing/selftests/bpf/xskxceiver.c
@@ -531,6 +531,18 @@ static struct pkt_stream *__pkt_stream_alloc(u32 nb_pkts)
        return pkt_stream;
 }
 
+static u32 ceil_u32(u32 a, u32 b)
+{
+       return (a + b - 1) / b;
+}
+
+static u32 pkt_nb_frags(u32 frame_size, struct pkt *pkt)
+{
+       if (!pkt || !pkt->valid)
+               return 1;
+       return ceil_u32(pkt->len, frame_size);
+}
+
 static void pkt_set(struct xsk_umem_info *umem, struct pkt *pkt, int offset, u32 len)
 {
        pkt->offset = offset;
@@ -1159,9 +1171,11 @@ static void thread_common_ops_tx(struct test_spec *test, struct ifobject *ifobje
        ifobject->umem->base_addr = 0;
 }
 
-static void xsk_populate_fill_ring(struct xsk_umem_info *umem, struct pkt_stream *pkt_stream)
+static void xsk_populate_fill_ring(struct xsk_umem_info *umem, struct pkt_stream *pkt_stream,
+                                  bool fill_up)
 {
-       u32 idx = 0, i, buffers_to_fill, nb_pkts;
+       u32 rx_frame_size = umem->frame_size - XDP_PACKET_HEADROOM;
+       u32 idx = 0, filled = 0, buffers_to_fill, nb_pkts;
        int ret;
 
        if (umem->num_frames < XSK_RING_PROD__DEFAULT_NUM_DESCS)
@@ -1173,19 +1187,29 @@ static void xsk_populate_fill_ring(struct xsk_umem_info *umem, struct pkt_stream
        if (ret != buffers_to_fill)
                exit_with_error(ENOSPC);
 
-       for (i = 0; i < buffers_to_fill; i++) {
+       while (filled < buffers_to_fill) {
                struct pkt *pkt = pkt_stream_get_next_rx_pkt(pkt_stream, &nb_pkts);
                u64 addr;
+               u32 i;
+
+               for (i = 0; i < pkt_nb_frags(rx_frame_size, pkt); i++) {
+                       if (!pkt) {
+                               if (!fill_up)
+                                       break;
+                               addr = filled * umem->frame_size + umem->base_addr;
+                       } else if (pkt->offset >= 0) {
+                               addr = pkt->offset % umem->frame_size + umem_alloc_buffer(umem);
+                       } else {
+                               addr = pkt->offset + umem_alloc_buffer(umem);
+                       }
 
-               if (!pkt)
-                       addr = i * umem->frame_size + umem->base_addr;
-               else if (pkt->offset >= 0)
-                       addr = pkt->offset % umem->frame_size + umem_alloc_buffer(umem);
-               else
-                       addr = pkt->offset + umem_alloc_buffer(umem);
-               *xsk_ring_prod__fill_addr(&umem->fq, idx++) = addr;
+                       *xsk_ring_prod__fill_addr(&umem->fq, idx++) = addr;
+                       if (++filled >= buffers_to_fill)
+                               break;
+               }
        }
-       xsk_ring_prod__submit(&umem->fq, i);
+       xsk_ring_prod__submit(&umem->fq, filled);
+       xsk_ring_prod__cancel(&umem->fq, buffers_to_fill - filled);
 
        pkt_stream_reset(pkt_stream);
        umem_reset_alloc(umem);
@@ -1220,7 +1244,7 @@ static void thread_common_ops(struct test_spec *test, struct ifobject *ifobject)
        if (!ifobject->rx_on)
                return;
 
-       xsk_populate_fill_ring(ifobject->umem, ifobject->pkt_stream);
+       xsk_populate_fill_ring(ifobject->umem, ifobject->pkt_stream, ifobject->use_fill_ring);
 
        ret = xsk_update_xskmap(ifobject->xskmap, ifobject->xsk->xsk);
        if (ret)