diff --git a/src/plugins/ixge/ixge.c b/src/plugins/ixge/ixge.c
index 62f484e..0586281 100644
--- a/src/plugins/ixge/ixge.c
+++ b/src/plugins/ixge/ixge.c
@@ -1462,14 +1462,10 @@
 	  to_add -= 2;
 
 #if 0
-	  ASSERT (VLIB_BUFFER_KNOWN_ALLOCATED ==
-		  vlib_buffer_is_known (vm, bi0));
-	  ASSERT (VLIB_BUFFER_KNOWN_ALLOCATED ==
-		  vlib_buffer_is_known (vm, bi1));
-	  ASSERT (VLIB_BUFFER_KNOWN_ALLOCATED ==
-		  vlib_buffer_is_known (vm, fi0));
-	  ASSERT (VLIB_BUFFER_KNOWN_ALLOCATED ==
-		  vlib_buffer_is_known (vm, fi1));
+	  ASSERT (VLIB_BUFFER_KNOWN_ALLOCATED == vlib_buffer_is_known (bi0));
+	  ASSERT (VLIB_BUFFER_KNOWN_ALLOCATED == vlib_buffer_is_known (bi1));
+	  ASSERT (VLIB_BUFFER_KNOWN_ALLOCATED == vlib_buffer_is_known (fi0));
+	  ASSERT (VLIB_BUFFER_KNOWN_ALLOCATED == vlib_buffer_is_known (fi1));
 #endif
 
 	  b0 = vlib_get_buffer (vm, bi0);
@@ -1680,10 +1676,8 @@
 	  to_add -= 1;
 
 #if 0
-	  ASSERT (VLIB_BUFFER_KNOWN_ALLOCATED ==
-		  vlib_buffer_is_known (vm, bi0));
-	  ASSERT (VLIB_BUFFER_KNOWN_ALLOCATED ==
-		  vlib_buffer_is_known (vm, fi0));
+	  ASSERT (VLIB_BUFFER_KNOWN_ALLOCATED == vlib_buffer_is_known (bi0));
+	  ASSERT (VLIB_BUFFER_KNOWN_ALLOCATED == vlib_buffer_is_known (fi0));
 #endif
 
 	  b0 = vlib_get_buffer (vm, bi0);
diff --git a/src/vlib/buffer.c b/src/vlib/buffer.c
index 880cd95..400488d 100644
--- a/src/vlib/buffer.c
+++ b/src/vlib/buffer.c
@@ -185,7 +185,7 @@
       vlib_buffer_known_state_t k;
       u8 *msg, *result;
 
-      k = vlib_buffer_is_known (vm, b->next_buffer);
+      k = vlib_buffer_is_known (b->next_buffer);
       if (k != VLIB_BUFFER_KNOWN_ALLOCATED)
 	return format (0, "next 0x%x: %U",
 		       b->next_buffer, format_vlib_buffer_known_state, k);
@@ -243,7 +243,7 @@
 	  goto done;
 	}
 
-      k = vlib_buffer_is_known (vm, bi);
+      k = vlib_buffer_is_known (bi);
       if (k != known_state)
 	{
 	  msg = format (0, "is %U; expected %U",
@@ -317,7 +317,7 @@
 
       bi = b[0];
       b += 1;
-      known = vlib_buffer_is_known (vm, bi);
+      known = vlib_buffer_is_known (bi);
       if (known != expected_state)
 	{
 	  ASSERT (0);
@@ -328,8 +328,7 @@
 	}
 
       vlib_buffer_set_known_state
-	(vm, bi,
-	 is_free ? VLIB_BUFFER_KNOWN_FREE : VLIB_BUFFER_KNOWN_ALLOCATED);
+	(bi, is_free ? VLIB_BUFFER_KNOWN_FREE : VLIB_BUFFER_KNOWN_ALLOCATED);
     }
 }
 
@@ -580,7 +579,7 @@
 	  bi[i] = vlib_get_buffer_index (vm, b);
 
 	  if (CLIB_DEBUG > 0)
-	    vlib_buffer_set_known_state (vm, bi[i], VLIB_BUFFER_KNOWN_FREE);
+	    vlib_buffer_set_known_state (bi[i], VLIB_BUFFER_KNOWN_FREE);
 	  b = vlib_buffer_next_contiguous (b, fl->n_data_bytes);
 	}
 
diff --git a/src/vlib/buffer_funcs.h b/src/vlib/buffer_funcs.h
index 06cc6da..4831eb5 100644
--- a/src/vlib/buffer_funcs.h
+++ b/src/vlib/buffer_funcs.h
@@ -222,9 +222,9 @@
 				      expected_state);
 
 always_inline vlib_buffer_known_state_t
-vlib_buffer_is_known (vlib_main_t * vm, u32 buffer_index)
+vlib_buffer_is_known (u32 buffer_index)
 {
-  vlib_buffer_main_t *bm = vm->buffer_main;
+  vlib_buffer_main_t *bm = vlib_global_main.buffer_main;
 
   clib_spinlock_lock (&bm->buffer_known_hash_lockp);
   uword *p = hash_get (bm->buffer_known_hash, buffer_index);
@@ -233,11 +233,11 @@
 }
 
 always_inline void
-vlib_buffer_set_known_state (vlib_main_t * vm,
-			     u32 buffer_index,
+vlib_buffer_set_known_state (u32 buffer_index,
 			     vlib_buffer_known_state_t state)
 {
-  vlib_buffer_main_t *bm = vm->buffer_main;
+  vlib_buffer_main_t *bm = vlib_global_main.buffer_main;
+
   clib_spinlock_lock (&bm->buffer_known_hash_lockp);
   hash_set (bm->buffer_known_hash, buffer_index, state);
   clib_spinlock_unlock (&bm->buffer_known_hash_lockp);
diff --git a/src/vnet/replication.c b/src/vnet/replication.c
index 5a8a0fe..217aa76 100644
--- a/src/vnet/replication.c
+++ b/src/vnet/replication.c
@@ -220,8 +220,7 @@
 
 #if (CLIB_DEBUG > 0)
 	  if (vm->buffer_main->callbacks_registered == 0)
-	    vlib_buffer_set_known_state (vm, bi0,
-					 VLIB_BUFFER_KNOWN_ALLOCATED);
+	    vlib_buffer_set_known_state (bi0, VLIB_BUFFER_KNOWN_ALLOCATED);
 #endif
 
 	  /* If buffer is traced, mark frame as traced */