vhost: add debug vhost-user on | off CLI

Add runtime debug vhost-user on | off CLI to facilitate troubleshooting.
This feature is needed to avoid recompiling the code to debug vhost issues.
The debugging messages should not be on the data path to avoid performance
hit.

Change-Id: I4c40f65dbb222557cba3fb8706fa3b7b62eec95f
Signed-off-by: Steven <sluong@cisco.com>

2 files changed, 59 insertions, 20 deletions

diff --git a/src/vnet/devices/virtio/vhost-user.c b/src/vnet/devices/virtio/vhost-user.c
index 23188934..2e2b49c2 100644
--- a/src/vnet/devices/virtio/vhost-user.c
+++ b/src/vnet/devices/virtio/vhost-user.c
@@ -49,14 +49,14 @@
  */
 
 
-#define VHOST_USER_DEBUG_SOCKET 0
 #define VHOST_DEBUG_VQ 0
 
-#if VHOST_USER_DEBUG_SOCKET == 1
-#define DBG_SOCK(args...) clib_warning(args);
-#else
-#define DBG_SOCK(args...)
-#endif
+#define DBG_SOCK(args...)			\
+  {						\
+    vhost_user_main_t *_vum = &vhost_user_main; \
+    if (_vum->debug)				\
+      clib_warning(args);			\
+  };
 
 #if VHOST_DEBUG_VQ == 1
 #define DBG_VQ(args...) clib_warning(args);
@@ -483,8 +483,6 @@ vhost_user_callfd_read_ready (unix_file_t * uf)
   u8 buff[8];
 
   n = read (uf->file_descriptor, ((char *) &buff), 8);
-  DBG_SOCK ("if %d CALL queue %d", uf->private_data >> 8,
-	    uf->private_data & 0xff);
 
   return 0;
 }
@@ -921,7 +919,7 @@ vhost_user_socket_read (unix_file_t * uf)
       break;
 
     case VHOST_USER_SET_VRING_CALL:
-      DBG_SOCK ("if %d msg VHOST_USER_SET_VRING_CALL u64 %d",
+      DBG_SOCK ("if %d msg VHOST_USER_SET_VRING_CALL %d",
 		vui->hw_if_index, msg.u64);
 
       q = (u8) (msg.u64 & 0xFF);
@@ -954,7 +952,7 @@ vhost_user_socket_read (unix_file_t * uf)
       break;
 
     case VHOST_USER_SET_VRING_KICK:
-      DBG_SOCK ("if %d msg VHOST_USER_SET_VRING_KICK u64 %d",
+      DBG_SOCK ("if %d msg VHOST_USER_SET_VRING_KICK %d",
 		vui->hw_if_index, msg.u64);
 
       q = (u8) (msg.u64 & 0xFF);
@@ -992,7 +990,7 @@ vhost_user_socket_read (unix_file_t * uf)
       break;
 
     case VHOST_USER_SET_VRING_ERR:
-      DBG_SOCK ("if %d msg VHOST_USER_SET_VRING_ERR u64 %d",
+      DBG_SOCK ("if %d msg VHOST_USER_SET_VRING_ERR %d",
 		vui->hw_if_index, msg.u64);
 
       q = (u8) (msg.u64 & 0xFF);
@@ -1020,9 +1018,6 @@ vhost_user_socket_read (unix_file_t * uf)
       break;
 
     case VHOST_USER_GET_VRING_BASE:
-      DBG_SOCK ("if %d msg VHOST_USER_GET_VRING_BASE idx %d num %d",
-		vui->hw_if_index, msg.state.index, msg.state.num);
-
       if (msg.state.index >= VHOST_VRING_MAX_N)
 	{
 	  DBG_SOCK ("invalid vring index VHOST_USER_GET_VRING_BASE:"
@@ -1040,6 +1035,8 @@ vhost_user_socket_read (unix_file_t * uf)
 
       /* Spec says: Client must [...] stop ring upon receiving VHOST_USER_GET_VRING_BASE. */
       vhost_user_vring_close (vui, msg.state.index);
+      DBG_SOCK ("if %d msg VHOST_USER_GET_VRING_BASE idx %d num %d",
+		vui->hw_if_index, msg.state.index, msg.state.num);
       break;
 
     case VHOST_USER_NONE:
@@ -1101,28 +1098,30 @@ vhost_user_socket_read (unix_file_t * uf)
       break;
 
     case VHOST_USER_GET_PROTOCOL_FEATURES:
-      DBG_SOCK ("if %d msg VHOST_USER_GET_PROTOCOL_FEATURES",
-		vui->hw_if_index);
-
       msg.flags |= 4;
       msg.u64 = (1 << VHOST_USER_PROTOCOL_F_LOG_SHMFD) |
 	(1 << VHOST_USER_PROTOCOL_F_MQ);
       msg.size = sizeof (msg.u64);
+      DBG_SOCK
+	("if %d msg VHOST_USER_GET_PROTOCOL_FEATURES - reply 0x%016llx",
+	 vui->hw_if_index, msg.u64);
       break;
 
     case VHOST_USER_SET_PROTOCOL_FEATURES:
-      DBG_SOCK ("if %d msg VHOST_USER_SET_PROTOCOL_FEATURES features 0x%lx",
-		vui->hw_if_index, msg.u64);
+      DBG_SOCK
+	("if %d msg VHOST_USER_SET_PROTOCOL_FEATURES features 0x%016llx",
+	 vui->hw_if_index, msg.u64);
 
       vui->protocol_features = msg.u64;
 
       break;
 
     case VHOST_USER_GET_QUEUE_NUM:
-      DBG_SOCK ("if %d msg VHOST_USER_GET_QUEUE_NUM", vui->hw_if_index);
       msg.flags |= 4;
       msg.u64 = VHOST_VRING_MAX_N;
       msg.size = sizeof (msg.u64);
+      DBG_SOCK ("if %d msg VHOST_USER_GET_QUEUE_NUM - reply %d",
+		vui->hw_if_index, msg.u64);
       break;
 
     case VHOST_USER_SET_VRING_ENABLE:
@@ -3533,6 +3532,43 @@ VLIB_CLI_COMMAND (show_vhost_user_command, static) = {
 };
 /* *INDENT-ON* */
 
+clib_error_t *
+debug_vhost_user_command_fn (vlib_main_t * vm,
+			     unformat_input_t * input,
+			     vlib_cli_command_t * cmd)
+{
+  unformat_input_t _line_input, *line_input = &_line_input;
+  clib_error_t *error = NULL;
+  vhost_user_main_t *vum = &vhost_user_main;
+
+  /* Get a line of input. */
+  if (!unformat_user (input, unformat_line_input, line_input))
+    return 0;
+
+  while (unformat_check_input (line_input) != UNFORMAT_END_OF_INPUT)
+    {
+      if (unformat (line_input, "on"))
+	vum->debug = 1;
+      else if (unformat (line_input, "off"))
+	vum->debug = 0;
+      else
+	error = clib_error_return (0, "unknown input `%U'",
+				   format_unformat_error, line_input);
+    }
+
+  unformat_free (line_input);
+
+  return error;
+}
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (debug_vhost_user_command, static) = {
+    .path = "debug vhost-user",
+    .short_help = "debug vhost-user <on | off>",
+    .function = debug_vhost_user_command_fn,
+};
+/* *INDENT-ON* */
+
 static clib_error_t *
 vhost_user_config (vlib_main_t * vm, unformat_input_t * input)
 {
diff --git a/src/vnet/devices/virtio/vhost-user.h b/src/vnet/devices/virtio/vhost-user.h
index ceced342..ed147a47 100644
--- a/src/vnet/devices/virtio/vhost-user.h
+++ b/src/vnet/devices/virtio/vhost-user.h
@@ -310,6 +310,9 @@ typedef struct
 
   /* The number of rx interface/queue pairs in interrupt mode */
   u32 ifq_count;
+
+  /* debug on or off */
+  u8 debug;
 } vhost_user_main_t;
 
 typedef struct