virtio: move retry logic to outer function

[vpp.git] / src / vnet / devices / virtio / device.c

diff --git a/src/vnet/devices/virtio/device.c b/src/vnet/devices/virtio/device.c
index 521d76a..29b38a2 100644 (file)
--- a/src/vnet/devices/virtio/device.c
+++ b/src/vnet/devices/virtio/device.c
@@ -541,29 +541,17 @@ virtio_find_free_desc (virtio_vring_t * vring, u16 size, u16 mask,
     }
 }
 
-static_always_inline uword
+static_always_inline u16
 virtio_interface_tx_gso_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
-                               vlib_frame_t * frame, virtio_if_t * vif,
+                               virtio_if_t * vif,
                                virtio_if_type_t type, virtio_vring_t * vring,
-                               int do_gso, int csum_offload)
+                               u32 * buffers, u16 n_left, int do_gso,
+                               int csum_offload)
 {
-  u16 n_left = frame->n_vectors;
   u16 used, next, avail, n_buffers = 0, n_buffers_left = 0;
   u16 sz = vring->size;
   u16 mask = sz - 1;
-  u16 retry_count = 2;
-  u32 *buffers = vlib_frame_vector_args (frame);
-  u32 to[GRO_TO_VECTOR_SIZE (n_left)];
-
-  if (do_gso && vif->packet_coalesce)
-    {
-      n_left = vnet_gro_inline (vm, vring->flow_table, buffers, n_left, to);
-      buffers = to;
-    }
-
-retry:
-  /* free consumed buffers */
-  virtio_free_used_device_desc (vm, vring, node->node_index);
+  u16 n_vectors = n_left;
 
   used = vring->desc_in_use;
   next = vring->desc_next;
@@ -642,7 +630,7 @@ retry:
       free_desc_count -= n_added;
     }
 
-  if (n_left != frame->n_vectors || n_buffers != n_buffers_left)
+  if (n_left != n_vectors || n_buffers != n_buffers_left)
     {
       CLIB_MEMORY_STORE_BARRIER ();
       vring->avail->idx = avail;
@@ -652,47 +640,30 @@ retry:
        virtio_kick (vm, vring, vif);
     }
 
-  if (n_left)
-    {
-      if (retry_count--)
-       goto retry;
-
-      if (vif->packet_buffering)
-       {
-
-         u16 n_buffered =
-           virtio_vring_buffering_store_packets (vring->buffering, buffers,
-                                                 n_left);
-         buffers += n_buffered;
-         n_left -= n_buffered;
-       }
-      if (n_left)
-       virtio_interface_drop_inline (vm, node->node_index,
-                                     buffers, n_left,
-                                     VIRTIO_TX_ERROR_NO_FREE_SLOTS);
-    }
-
-  return frame->n_vectors - n_left;
+  return n_left;
 }
 
-static_always_inline uword
+static_always_inline u16
 virtio_interface_tx_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
-                           vlib_frame_t * frame, virtio_if_t * vif,
-                           virtio_vring_t * vring, virtio_if_type_t type)
+                           virtio_if_t * vif,
+                           virtio_vring_t * vring, virtio_if_type_t type,
+                           u32 * buffers, u16 n_left)
 {
   vnet_main_t *vnm = vnet_get_main ();
   vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, vif->hw_if_index);
 
   if (hw->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO)
-    return virtio_interface_tx_gso_inline (vm, node, frame, vif, type, vring,
-                                          1 /* do_gso */ ,
+    return virtio_interface_tx_gso_inline (vm, node, vif, type, vring,
+                                          buffers, n_left, 1 /* do_gso */ ,
                                           1 /* checksum offload */ );
   else if (hw->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_TX_L4_CKSUM_OFFLOAD)
-    return virtio_interface_tx_gso_inline (vm, node, frame, vif, type, vring,
+    return virtio_interface_tx_gso_inline (vm, node, vif, type, vring,
+                                          buffers, n_left,
                                           0 /* no do_gso */ ,
                                           1 /* checksum offload */ );
   else
-    return virtio_interface_tx_gso_inline (vm, node, frame, vif, type, vring,
+    return virtio_interface_tx_gso_inline (vm, node, vif, type, vring,
+                                          buffers, n_left,
                                           0 /* no do_gso */ ,
                                           0 /* no checksum offload */ );
 }
@@ -706,7 +677,9 @@ VNET_DEVICE_CLASS_TX_FN (virtio_device_class) (vlib_main_t * vm,
   virtio_if_t *vif = pool_elt_at_index (nm->interfaces, rund->dev_instance);
   u16 qid = vm->thread_index % vif->num_txqs;
   virtio_vring_t *vring = vec_elt_at_index (vif->txq_vrings, qid);
-  uword rv = 0;
+  u16 n_left = frame->n_vectors;
+  u32 *buffers = vlib_frame_vector_args (frame);
+  u32 to[GRO_TO_VECTOR_SIZE (n_left)];
 
   clib_spinlock_lock_if_init (&vring->lockp);
 
@@ -714,21 +687,49 @@ VNET_DEVICE_CLASS_TX_FN (virtio_device_class) (vlib_main_t * vm,
       (vring->last_kick_avail_idx != vring->avail->idx))
     virtio_kick (vm, vring, vif);
 
+  if (vif->packet_coalesce)
+    {
+      n_left = vnet_gro_inline (vm, vring->flow_table, buffers, n_left, to);
+      buffers = to;
+    }
+
+  u16 retry_count = 2;
+
+retry:
+  /* free consumed buffers */
+  virtio_free_used_device_desc (vm, vring, node->node_index);
+
   if (vif->type == VIRTIO_IF_TYPE_TAP)
-    rv = virtio_interface_tx_inline (vm, node, frame, vif, vring,
-                                    VIRTIO_IF_TYPE_TAP);
+    n_left = virtio_interface_tx_inline (vm, node, vif, vring,
+                                        VIRTIO_IF_TYPE_TAP, buffers, n_left);
   else if (vif->type == VIRTIO_IF_TYPE_PCI)
-    rv = virtio_interface_tx_inline (vm, node, frame, vif, vring,
-                                    VIRTIO_IF_TYPE_PCI);
+    n_left = virtio_interface_tx_inline (vm, node, vif, vring,
+                                        VIRTIO_IF_TYPE_PCI, buffers, n_left);
   else if (vif->type == VIRTIO_IF_TYPE_TUN)
-    rv = virtio_interface_tx_inline (vm, node, frame, vif, vring,
-                                    VIRTIO_IF_TYPE_TUN);
+    n_left = virtio_interface_tx_inline (vm, node, vif, vring,
+                                        VIRTIO_IF_TYPE_TUN, buffers, n_left);
   else
     ASSERT (0);
 
+  if (n_left && retry_count--)
+    goto retry;
+
+  if (vif->packet_buffering && n_left)
+    {
+      u16 n_buffered =
+       virtio_vring_buffering_store_packets (vring->buffering, buffers,
+                                             n_left);
+      buffers += n_buffered;
+      n_left -= n_buffered;
+    }
+  if (n_left)
+    virtio_interface_drop_inline (vm, node->node_index,
+                                 buffers + frame->n_vectors - n_left, n_left,
+                                 VIRTIO_TX_ERROR_NO_FREE_SLOTS);
+
   clib_spinlock_unlock_if_init (&vring->lockp);
 
-  return rv;
+  return frame->n_vectors - n_left;
 }
 
 static void