tap: split gso and checksum offload functionality

Type: refactor

Change-Id: I0d4b79ef384c11c841576d264bfd8ccb21783e10
Signed-off-by: Mohsin Kazmi <sykazmi@cisco.com>

4 files changed, 107 insertions, 17 deletions

diff --git a/src/vnet/devices/tap/cli.c b/src/vnet/devices/tap/cli.c
index a85fcbff25c..8d5e3b44e31 100644
--- a/src/vnet/devices/tap/cli.c
+++ b/src/vnet/devices/tap/cli.c
@@ -89,6 +89,8 @@ tap_create_command_fn (vlib_main_t * vm, unformat_input_t * input,
 	    args.tap_flags &= ~TAP_FLAG_GSO;
 	  else if (unformat (line_input, "gso"))
 	    args.tap_flags |= TAP_FLAG_GSO;
+	  else if (unformat (line_input, "csum-offload"))
+	    args.tap_flags |= TAP_FLAG_CSUM_OFFLOAD;
 	  else if (unformat (line_input, "hw-addr %U",
 			     unformat_ethernet_address, args.mac_addr.bytes))
 	    args.mac_addr_set = 1;
@@ -128,7 +130,7 @@ VLIB_CLI_COMMAND (tap_create_command, static) = {
     "[host-bridge <bridge-name>] [host-ip4-addr <ip4addr/mask>] "
     "[host-ip6-addr <ip6-addr>] [host-ip4-gw <ip4-addr>] "
     "[host-ip6-gw <ip6-addr>] [host-mac-addr <host-mac-address>] "
-    "[host-if-name <name>] [host-mtu-size <size>] [no-gso|gso]",
+    "[host-if-name <name>] [host-mtu-size <size>] [no-gso|gso|csum-offload]",
   .function = tap_create_command_fn,
 };
 /* *INDENT-ON* */
@@ -182,14 +184,15 @@ VLIB_CLI_COMMAND (tap_delete__command, static) =
 /* *INDENT-ON* */
 
 static clib_error_t *
-tap_gso_command_fn (vlib_main_t * vm, unformat_input_t * input,
-		    vlib_cli_command_t * cmd)
+tap_offload_command_fn (vlib_main_t * vm, unformat_input_t * input,
+			vlib_cli_command_t * cmd)
 {
   unformat_input_t _line_input, *line_input = &_line_input;
   u32 sw_if_index = ~0;
   vnet_main_t *vnm = vnet_get_main ();
-  int enable = 1;
-  int rv;
+  int gso_enable = 0, gso_disable = 0;
+  int csum_offload_enable = 0, csum_offload_disable = 0;
+  int rv = 0;
 
   /* Get a line of input. */
   if (!unformat_user (input, unformat_line_input, line_input))
@@ -202,10 +205,14 @@ tap_gso_command_fn (vlib_main_t * vm, unformat_input_t * input,
       else if (unformat (line_input, "%U", unformat_vnet_sw_interface,
 			 vnm, &sw_if_index))
 	;
-      else if (unformat (line_input, "enable"))
-	enable = 1;
-      else if (unformat (line_input, "disable"))
-	enable = 0;
+      else if (unformat (line_input, "gso-enable"))
+	gso_enable = 1;
+      else if (unformat (line_input, "gso-disable"))
+	gso_disable = 1;
+      else if (unformat (line_input, "csum-offload-enable"))
+	csum_offload_enable = 1;
+      else if (unformat (line_input, "csum-offload-disable"))
+	csum_offload_disable = 1;
       else
 	return clib_error_return (0, "unknown input `%U'",
 				  format_unformat_error, input);
@@ -216,7 +223,15 @@ tap_gso_command_fn (vlib_main_t * vm, unformat_input_t * input,
     return clib_error_return (0,
 			      "please specify interface name or sw_if_index");
 
-  rv = tap_gso_enable_disable (vm, sw_if_index, enable);
+  if (gso_enable)
+    rv = tap_gso_enable_disable (vm, sw_if_index, 1);
+  else if (csum_offload_enable)
+    rv = tap_csum_offload_enable_disable (vm, sw_if_index, 1);
+  else if (gso_disable)
+    rv = tap_gso_enable_disable (vm, sw_if_index, 0);
+  else if (csum_offload_disable)
+    rv = tap_csum_offload_enable_disable (vm, sw_if_index, 0);
+
   if (rv == VNET_API_ERROR_INVALID_SW_IF_INDEX)
     return clib_error_return (0, "not a tap interface");
   else if (rv != 0)
@@ -226,11 +241,12 @@ tap_gso_command_fn (vlib_main_t * vm, unformat_input_t * input,
 }
 
 /* *INDENT-OFF* */
-VLIB_CLI_COMMAND (tap_gso__command, static) =
+VLIB_CLI_COMMAND (tap_offload_command, static) =
 {
-  .path = "set tap gso",
-  .short_help = "set tap gso {<interface> | sw_if_index <sw_idx>} <enable|disable>",
-  .function = tap_gso_command_fn,
+  .path = "set tap offload",
+  .short_help = "set tap offload {<interface> | sw_if_index <sw_idx>}"
+    " <gso-enable | gso-disable | csum-offload-enable | csum-offload-disable>",
+  .function = tap_offload_command_fn,
 };
 /* *INDENT-ON* */
 
diff --git a/src/vnet/devices/tap/tap.c b/src/vnet/devices/tap/tap.c
index 061c6ac26a1..a1cb69d2cf6 100644
--- a/src/vnet/devices/tap/tap.c
+++ b/src/vnet/devices/tap/tap.c
@@ -210,6 +210,11 @@ tap_create_if (vlib_main_t * vm, tap_create_if_args_t * args)
       offload = TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6;
       vif->gso_enabled = 1;
     }
+  else if (args->tap_flags & TAP_FLAG_CSUM_OFFLOAD)
+    {
+      offload = TUN_F_CSUM;
+      vif->csum_offload_enabled = 1;
+    }
 
   _IOCTL (tfd, TUNSETIFF, (void *) &ifr);
   tap_log_dbg (vif, "TUNSETIFF fd %d name %s flags 0x%x", tfd,
@@ -594,7 +599,12 @@ tap_create_if (vlib_main_t * vm, tap_create_if_args_t * args)
   hw->flags |= VNET_HW_INTERFACE_FLAG_SUPPORTS_INT_MODE;
   if (args->tap_flags & TAP_FLAG_GSO)
     {
-      hw->flags |= VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO;
+      hw->flags |= VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO |
+	VNET_HW_INTERFACE_FLAG_SUPPORTS_TX_L4_CKSUM_OFFLOAD;
+    }
+  else if (args->tap_flags & TAP_FLAG_CSUM_OFFLOAD)
+    {
+      hw->flags |= VNET_HW_INTERFACE_FLAG_SUPPORTS_TX_L4_CKSUM_OFFLOAD;
     }
   vnet_hw_interface_set_input_node (vnm, vif->hw_if_index,
 				    virtio_input_node.index);
@@ -666,6 +676,62 @@ tap_delete_if (vlib_main_t * vm, u32 sw_if_index)
 }
 
 int
+tap_csum_offload_enable_disable (vlib_main_t * vm, u32 sw_if_index,
+				 int enable_disable)
+{
+  vnet_main_t *vnm = vnet_get_main ();
+  virtio_main_t *mm = &virtio_main;
+  virtio_if_t *vif;
+  vnet_hw_interface_t *hw;
+  clib_error_t *err = 0;
+
+  hw = vnet_get_sup_hw_interface_api_visible_or_null (vnm, sw_if_index);
+
+  if (hw == NULL || virtio_device_class.index != hw->dev_class_index)
+    return VNET_API_ERROR_INVALID_SW_IF_INDEX;
+
+  vif = pool_elt_at_index (mm->interfaces, hw->dev_instance);
+
+  const unsigned int csum_offload_on = TUN_F_CSUM;
+  const unsigned int csum_offload_off = 0;
+  unsigned int offload = enable_disable ? csum_offload_on : csum_offload_off;
+  _IOCTL (vif->tap_fd, TUNSETOFFLOAD, offload);
+  vif->gso_enabled = 0;
+  vif->csum_offload_enabled = enable_disable ? 1 : 0;
+
+  if ((hw->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO) != 0)
+    {
+      hw->flags &= ~VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO;
+    }
+
+  if (enable_disable)
+    {
+      if ((hw->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_TX_L4_CKSUM_OFFLOAD) ==
+	  0)
+	{
+	  hw->flags |= VNET_HW_INTERFACE_FLAG_SUPPORTS_TX_L4_CKSUM_OFFLOAD;
+	}
+    }
+  else
+    {
+      if ((hw->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_TX_L4_CKSUM_OFFLOAD) !=
+	  0)
+	{
+	  hw->flags &= ~VNET_HW_INTERFACE_FLAG_SUPPORTS_TX_L4_CKSUM_OFFLOAD;
+	}
+    }
+
+error:
+  if (err)
+    {
+      clib_warning ("Error %s checksum offload on sw_if_index %d",
+		    enable_disable ? "enabling" : "disabling", sw_if_index);
+      return VNET_API_ERROR_SYSCALL_ERROR_3;
+    }
+  return 0;
+}
+
+int
 tap_gso_enable_disable (vlib_main_t * vm, u32 sw_if_index, int enable_disable)
 {
   vnet_main_t *vnm = vnet_get_main ();
@@ -686,18 +752,21 @@ tap_gso_enable_disable (vlib_main_t * vm, u32 sw_if_index, int enable_disable)
   unsigned int offload = enable_disable ? gso_on : gso_off;
   _IOCTL (vif->tap_fd, TUNSETOFFLOAD, offload);
   vif->gso_enabled = enable_disable ? 1 : 0;
+  vif->csum_offload_enabled = 0;
   if (enable_disable)
     {
       if ((hw->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO) == 0)
 	{
-	  hw->flags |= VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO;
+	  hw->flags |= VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO |
+	    VNET_HW_INTERFACE_FLAG_SUPPORTS_TX_L4_CKSUM_OFFLOAD;
 	}
     }
   else
     {
       if ((hw->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO) != 0)
 	{
-	  hw->flags &= ~VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO;
+	  hw->flags &= ~(VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO |
+			 VNET_HW_INTERFACE_FLAG_SUPPORTS_TX_L4_CKSUM_OFFLOAD);
 	}
     }
 
diff --git a/src/vnet/devices/tap/tap.h b/src/vnet/devices/tap/tap.h
index 6eba7affa35..fd4006b5d52 100644
--- a/src/vnet/devices/tap/tap.h
+++ b/src/vnet/devices/tap/tap.h
@@ -32,6 +32,7 @@ typedef struct
   u16 tx_ring_sz;
   u32 tap_flags;
 #define TAP_FLAG_GSO (1 << 0)
+#define TAP_FLAG_CSUM_OFFLOAD (1 << 1)
   u8 *host_namespace;
   u8 *host_if_name;
   mac_address_t host_mac_addr;
@@ -88,6 +89,9 @@ void tap_create_if (vlib_main_t * vm, tap_create_if_args_t * args);
 int tap_delete_if (vlib_main_t * vm, u32 sw_if_index);
 int tap_gso_enable_disable (vlib_main_t * vm, u32 sw_if_index,
 			    int enable_disable);
+int
+tap_csum_offload_enable_disable (vlib_main_t * vm, u32 sw_if_index,
+				 int enable_disable);
 int tap_dump_ifs (tap_interface_details_t ** out_tapids);
 
 #endif /* _VNET_DEVICES_VIRTIO_TAP_H_ */
diff --git a/src/vnet/devices/tap/tapv2.api b/src/vnet/devices/tap/tapv2.api
index ec8bd4539b9..861fe170959 100644
--- a/src/vnet/devices/tap/tapv2.api
+++ b/src/vnet/devices/tap/tapv2.api
@@ -27,6 +27,7 @@ import "vnet/ip/ip_types.api";
 
 enum tap_flags {
         TAP_FLAG_GSO = 1,
+        TAP_FLAG_CSUM_OFFLOAD = 2,
 };
 
 /** \brief Initialize a new tap interface with the given parameters