ipsec: Store thread-index in buffer meta-data during SA handoff

Type: improvement

negates the need to load the SA in the handoff node.
don't prefetch the packet data, it's not needed.

Signed-off-by: Neale Ranns <neale@graphiant.com>
Change-Id: I340472dc437f050cc1c3c11dfeb47ab09c609624

6 files changed, 19 insertions, 32 deletions

diff --git a/src/vnet/ipsec/ah_decrypt.c b/src/vnet/ipsec/ah_decrypt.c
index 03a9dc859c8..107ccd2146d 100644
--- a/src/vnet/ipsec/ah_decrypt.c
+++ b/src/vnet/ipsec/ah_decrypt.c
@@ -187,6 +187,7 @@ ah_decrypt_inline (vlib_main_t * vm,
 
       if (PREDICT_TRUE (thread_index != sa0->thread_index))
 	{
+	  vnet_buffer (b[0])->ipsec.thread_index = sa0->thread_index;
 	  next[0] = AH_DECRYPT_NEXT_HANDOFF;
 	  goto next;
 	}
diff --git a/src/vnet/ipsec/ah_encrypt.c b/src/vnet/ipsec/ah_encrypt.c
index 610b95e8ce7..37dd25dc6de 100644
--- a/src/vnet/ipsec/ah_encrypt.c
+++ b/src/vnet/ipsec/ah_encrypt.c
@@ -195,6 +195,7 @@ ah_encrypt_inline (vlib_main_t * vm,
 
       if (PREDICT_TRUE (thread_index != sa0->thread_index))
 	{
+	  vnet_buffer (b[0])->ipsec.thread_index = sa0->thread_index;
 	  next[0] = AH_ENCRYPT_NEXT_HANDOFF;
 	  goto next;
 	}
diff --git a/src/vnet/ipsec/esp_decrypt.c b/src/vnet/ipsec/esp_decrypt.c
index e5277b1e1c2..a9aa9b8b7f4 100644
--- a/src/vnet/ipsec/esp_decrypt.c
+++ b/src/vnet/ipsec/esp_decrypt.c
@@ -1123,6 +1123,7 @@ esp_decrypt_inline (vlib_main_t * vm,
 
       if (PREDICT_FALSE (thread_index != sa0->thread_index))
 	{
+	  vnet_buffer (b[0])->ipsec.thread_index = sa0->thread_index;
 	  esp_set_next_index (is_async, from, nexts, from[b - bufs],
 			      &n_async_drop, ESP_DECRYPT_NEXT_HANDOFF, next);
 	  next[0] = ESP_DECRYPT_NEXT_HANDOFF;
diff --git a/src/vnet/ipsec/esp_encrypt.c b/src/vnet/ipsec/esp_encrypt.c
index e64de26327f..c76fccc718e 100644
--- a/src/vnet/ipsec/esp_encrypt.c
+++ b/src/vnet/ipsec/esp_encrypt.c
@@ -685,6 +685,7 @@ esp_encrypt_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
 
       if (PREDICT_FALSE (thread_index != sa0->thread_index))
 	{
+	  vnet_buffer (b[0])->ipsec.thread_index = sa0->thread_index;
 	  esp_set_next_index (is_async, from, nexts, from[b - bufs],
 			      &n_async_drop, handoff_next, next);
 	  goto trace;
diff --git a/src/vnet/ipsec/ipsec_handoff.c b/src/vnet/ipsec/ipsec_handoff.c
index 8bd6d22a588..9092f817857 100644
--- a/src/vnet/ipsec/ipsec_handoff.c
+++ b/src/vnet/ipsec/ipsec_handoff.c
@@ -60,9 +60,7 @@ ipsec_handoff (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame,
   vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
   u16 thread_indices[VLIB_FRAME_SIZE], *ti;
   u32 n_enq, n_left_from, *from;
-  ipsec_main_t *im;
 
-  im = &ipsec_main;
   from = vlib_frame_vector_args (frame);
   n_left_from = frame->n_vectors;
   vlib_get_buffers (vm, from, bufs, n_left_from);
@@ -72,9 +70,6 @@ ipsec_handoff (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame,
 
   while (n_left_from >= 4)
     {
-      ipsec_sa_t *sa0, *sa1, *sa2, *sa3;
-      u32 sai0, sai1, sai2, sai3;
-
       /* Prefetch next iteration. */
       if (n_left_from >= 12)
 	{
@@ -82,28 +77,14 @@ ipsec_handoff (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame,
 	  vlib_prefetch_buffer_header (b[9], LOAD);
 	  vlib_prefetch_buffer_header (b[10], LOAD);
 	  vlib_prefetch_buffer_header (b[11], LOAD);
-
-	  vlib_prefetch_buffer_data (b[4], LOAD);
-	  vlib_prefetch_buffer_data (b[5], LOAD);
-	  vlib_prefetch_buffer_data (b[6], LOAD);
-	  vlib_prefetch_buffer_data (b[7], LOAD);
 	}
 
-      sai0 = vnet_buffer (b[0])->ipsec.sad_index;
-      sai1 = vnet_buffer (b[1])->ipsec.sad_index;
-      sai2 = vnet_buffer (b[2])->ipsec.sad_index;
-      sai3 = vnet_buffer (b[3])->ipsec.sad_index;
-      sa0 = pool_elt_at_index (im->sad, sai0);
-      sa1 = pool_elt_at_index (im->sad, sai1);
-      sa2 = pool_elt_at_index (im->sad, sai2);
-      sa3 = pool_elt_at_index (im->sad, sai3);
-
-      ti[0] = sa0->thread_index;
-      ti[1] = sa1->thread_index;
-      ti[2] = sa2->thread_index;
-      ti[3] = sa3->thread_index;
-
-      if (node->flags & VLIB_NODE_FLAG_TRACE)
+      ti[0] = vnet_buffer (b[0])->ipsec.thread_index;
+      ti[1] = vnet_buffer (b[1])->ipsec.thread_index;
+      ti[2] = vnet_buffer (b[2])->ipsec.thread_index;
+      ti[3] = vnet_buffer (b[3])->ipsec.thread_index;
+
+      if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
 	{
 	  if (PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
 	    {
@@ -137,13 +118,7 @@ ipsec_handoff (vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame,
     }
   while (n_left_from > 0)
     {
-      ipsec_sa_t *sa0;
-      u32 sai0;
-
-      sai0 = vnet_buffer (b[0])->ipsec.sad_index;
-      sa0 = pool_elt_at_index (im->sad, sai0);
-
-      ti[0] = sa0->thread_index;
+      ti[0] = vnet_buffer (b[0])->ipsec.thread_index;
 
       if (PREDICT_FALSE (b[0]->flags & VLIB_BUFFER_IS_TRACED))
 	{
diff --git a/src/vnet/ipsec/ipsec_sa.h b/src/vnet/ipsec/ipsec_sa.h
index 84abd6ef4b4..a5756f556f9 100644
--- a/src/vnet/ipsec/ipsec_sa.h
+++ b/src/vnet/ipsec/ipsec_sa.h
@@ -223,6 +223,14 @@ typedef struct
 STATIC_ASSERT_OFFSET_OF (ipsec_sa_t, cacheline1, CLIB_CACHE_LINE_BYTES);
 STATIC_ASSERT_OFFSET_OF (ipsec_sa_t, cacheline2, 2 * CLIB_CACHE_LINE_BYTES);
 
+/*
+ * Ensure that the IPsec data does not overlap with the IP data in
+ * the buffer meta data
+ */
+STATIC_ASSERT (STRUCT_OFFSET_OF (vnet_buffer_opaque_t, ipsec.sad_index) ==
+		 STRUCT_OFFSET_OF (vnet_buffer_opaque_t, ip.save_protocol),
+	       "IPSec data is overlapping with IP data");
+
 #define _(a,v,s)                                                        \
   always_inline int                                                     \
   ipsec_sa_is_set_##v (const ipsec_sa_t *sa) {                          \