virtio: split gso and checksum offload functionality

Type: refactor

Change-Id: I897e36bd5db593b417c2bac9f739bc51cf45bc08
Signed-off-by: Mohsin Kazmi <sykazmi@cisco.com>

9 files changed, 312 insertions, 44 deletions

diff --git a/src/vnet/devices/virtio/cli.c b/src/vnet/devices/virtio/cli.c
index 7291f17e645..1b37338af1f 100644
--- a/src/vnet/devices/virtio/cli.c
+++ b/src/vnet/devices/virtio/cli.c
@@ -44,6 +44,8 @@ virtio_pci_create_command_fn (vlib_main_t * vm, unformat_input_t * input,
 	args.features = feature_mask;
       else if (unformat (line_input, "gso-enabled"))
 	args.gso_enabled = 1;
+      else if (unformat (line_input, "csum-enabled"))
+	args.checksum_offload_enabled = 1;
       else
 	return clib_error_return (0, "unknown input `%U'",
 				  format_unformat_error, input);
@@ -59,7 +61,7 @@ virtio_pci_create_command_fn (vlib_main_t * vm, unformat_input_t * input,
 VLIB_CLI_COMMAND (virtio_pci_create_command, static) = {
   .path = "create interface virtio",
   .short_help = "create interface virtio <pci-address> "
-                "[feature-mask <hex-mask>] [gso-enabled]",
+                "[feature-mask <hex-mask>] [gso-enabled] [csum-enabled]",
   .function = virtio_pci_create_command_fn,
 };
 /* *INDENT-ON* */
@@ -118,6 +120,68 @@ VLIB_CLI_COMMAND (virtio_pci_delete_command, static) = {
 /* *INDENT-ON* */
 
 static clib_error_t *
+virtio_pci_enable_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_hw_interface_t *hw;
+  virtio_main_t *vim = &virtio_main;
+  virtio_if_t *vif;
+  vnet_main_t *vnm = vnet_get_main ();
+  int gso_enabled = 0, checksum_offload_enabled = 0;
+  int offloads_disabled = 0;
+
+  /* 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, "sw_if_index %d", &sw_if_index))
+	;
+      else if (unformat (line_input, "%U", unformat_vnet_sw_interface,
+			 vnm, &sw_if_index))
+	;
+      else if (unformat (line_input, "gso-enabled"))
+	gso_enabled = 1;
+      else if (unformat (line_input, "csum-offload-enabled"))
+	checksum_offload_enabled = 1;
+      else if (unformat (line_input, "offloads-disabled"))
+	offloads_disabled = 1;
+      else
+	return clib_error_return (0, "unknown input `%U'",
+				  format_unformat_error, input);
+    }
+  unformat_free (line_input);
+
+  if (sw_if_index == ~0)
+    return clib_error_return (0,
+			      "please specify interface name or sw_if_index");
+
+  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 clib_error_return (0, "not a virtio interface");
+
+  vif = pool_elt_at_index (vim->interfaces, hw->dev_instance);
+
+  if (virtio_pci_enable_disable_offloads
+      (vm, vif, gso_enabled, checksum_offload_enabled, offloads_disabled) < 0)
+    return clib_error_return (0, "not able to enable/disable offloads");
+
+  return 0;
+}
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (virtio_pci_enable_command, static) = {
+  .path = "set virtio pci",
+  .short_help = "set virtio pci {<interface> | sw_if_index <sw_idx>}"
+                " [gso-enabled | csum-offload-enabled | offloads-disabled]",
+  .function = virtio_pci_enable_command_fn,
+};
+/* *INDENT-ON* */
+
+static clib_error_t *
 show_virtio_pci_fn (vlib_main_t * vm, unformat_input_t * input,
 		    vlib_cli_command_t * cmd)
 {
diff --git a/src/vnet/devices/virtio/device.c b/src/vnet/devices/virtio/device.c
index 16d1c808643..ecc8b8c1aa7 100644
--- a/src/vnet/devices/virtio/device.c
+++ b/src/vnet/devices/virtio/device.c
@@ -22,8 +22,11 @@
 #include <vlib/vlib.h>
 #include <vlib/unix/unix.h>
 #include <vnet/ethernet/ethernet.h>
+#include <vnet/gso/gso.h>
 #include <vnet/ip/ip4_packet.h>
 #include <vnet/ip/ip6_packet.h>
+#include <vnet/tcp/tcp_packet.h>
+#include <vnet/udp/udp_packet.h>
 #include <vnet/devices/virtio/virtio.h>
 
 #define foreach_virtio_tx_func_error	       \
@@ -114,10 +117,46 @@ virtio_free_used_device_desc (vlib_main_t * vm, virtio_vring_t * vring)
   vring->last_used_idx = last;
 }
 
+static_always_inline void
+set_checksum_offsets (vlib_main_t * vm, virtio_if_t * vif, vlib_buffer_t * b,
+		      struct virtio_net_hdr_v1 *hdr)
+{
+  if (b->flags & VNET_BUFFER_F_IS_IP4)
+    {
+      ip4_header_t *ip4;
+      gso_header_offset_t gho = vnet_gso_header_offset_parser (b, 0);
+      hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
+      hdr->csum_start = gho.l4_hdr_offset;	// 0x22;
+      if (b->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM)
+	hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
+      else if (b->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM)
+	hdr->csum_offset = STRUCT_OFFSET_OF (udp_header_t, checksum);
+
+      /*
+       * virtio devices do not support IP4 checksum offload. So driver takes care
+       * of it while doing tx.
+       */
+      ip4 =
+	(ip4_header_t *) (vlib_buffer_get_current (b) + gho.l3_hdr_offset);
+      if (b->flags & VNET_BUFFER_F_OFFLOAD_IP_CKSUM)
+	ip4->checksum = ip4_header_checksum (ip4);
+    }
+  else if (b->flags & VNET_BUFFER_F_IS_IP6)
+    {
+      gso_header_offset_t gho = vnet_gso_header_offset_parser (b, 1);
+      hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
+      hdr->csum_start = gho.l4_hdr_offset;	// 0x36;
+      if (b->flags & VNET_BUFFER_F_OFFLOAD_TCP_CKSUM)
+	hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
+      else if (b->flags & VNET_BUFFER_F_OFFLOAD_UDP_CKSUM)
+	hdr->csum_offset = STRUCT_OFFSET_OF (udp_header_t, checksum);
+    }
+}
+
 static_always_inline u16
 add_buffer_to_slot (vlib_main_t * vm, virtio_if_t * vif,
 		    virtio_vring_t * vring, u32 bi, u16 avail, u16 next,
-		    u16 mask, int do_gso)
+		    u16 mask, int do_gso, int csum_offload)
 {
   u16 n_added = 0;
   int hdr_sz = vif->virtio_net_hdr_sz;
@@ -127,25 +166,46 @@ add_buffer_to_slot (vlib_main_t * vm, virtio_if_t * vif,
   struct virtio_net_hdr_v1 *hdr = vlib_buffer_get_current (b) - hdr_sz;
 
   clib_memset (hdr, 0, hdr_sz);
+
   if (do_gso && (b->flags & VNET_BUFFER_F_GSO))
     {
       if (b->flags & VNET_BUFFER_F_IS_IP4)
 	{
+	  ip4_header_t *ip4;
+	  gso_header_offset_t gho = vnet_gso_header_offset_parser (b, 0);
 	  hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
 	  hdr->gso_size = vnet_buffer2 (b)->gso_size;
+	  hdr->hdr_len = gho.l4_hdr_offset + gho.l4_hdr_sz;
 	  hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-	  hdr->csum_start = vnet_buffer (b)->l4_hdr_offset;	// 0x22;
-	  hdr->csum_offset = 0x10;
+	  hdr->csum_start = gho.l4_hdr_offset;	// 0x22;
+	  hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
+	  ip4 =
+	    (ip4_header_t *) (vlib_buffer_get_current (b) +
+			      gho.l3_hdr_offset);
+	  /*
+	   * virtio devices do not support IP4 checksum offload. So driver takes care
+	   * of it while doing tx.
+	   */
+	  if (b->flags & VNET_BUFFER_F_OFFLOAD_IP_CKSUM)
+	    ip4->checksum = ip4_header_checksum (ip4);
 	}
-      else
+      else if (b->flags & VNET_BUFFER_F_IS_IP6)
 	{
+	  gso_header_offset_t gho = vnet_gso_header_offset_parser (b, 1);
 	  hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
 	  hdr->gso_size = vnet_buffer2 (b)->gso_size;
+	  hdr->hdr_len = gho.l4_hdr_offset + gho.l4_hdr_sz;
 	  hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-	  hdr->csum_start = vnet_buffer (b)->l4_hdr_offset;	// 0x36;
-	  hdr->csum_offset = 0x10;
+	  hdr->csum_start = gho.l4_hdr_offset;	// 0x36;
+	  hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
 	}
     }
+  else if (csum_offload
+	   && (b->flags & (VNET_BUFFER_F_OFFLOAD_TCP_CKSUM |
+			   VNET_BUFFER_F_OFFLOAD_UDP_CKSUM)))
+    {
+      set_checksum_offsets (vm, vif, b, hdr);
+    }
 
   if (PREDICT_TRUE ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0))
     {
@@ -245,7 +305,7 @@ add_buffer_to_slot (vlib_main_t * vm, virtio_if_t * vif,
 static_always_inline uword
 virtio_interface_tx_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 			    vlib_frame_t * frame, virtio_if_t * vif,
-			    int do_gso)
+			    int do_gso, int csum_offload)
 {
   u16 n_left = frame->n_vectors;
   virtio_vring_t *vring;
@@ -274,7 +334,7 @@ virtio_interface_tx_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
       u16 n_added = 0;
       n_added =
 	add_buffer_to_slot (vm, vif, vring, buffers[0], avail, next, mask,
-			    do_gso);
+			    do_gso, csum_offload);
       if (!n_added)
 	break;
       avail += n_added;
@@ -310,15 +370,21 @@ VNET_DEVICE_CLASS_TX_FN (virtio_device_class) (vlib_main_t * vm,
 					       vlib_node_runtime_t * node,
 					       vlib_frame_t * frame)
 {
+  vnet_main_t *vnm = vnet_get_main ();
   virtio_main_t *nm = &virtio_main;
   vnet_interface_output_runtime_t *rund = (void *) node->runtime_data;
   virtio_if_t *vif = pool_elt_at_index (nm->interfaces, rund->dev_instance);
+  vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, vif->hw_if_index);
 
-  if (vif->gso_enabled > 0)
-    return virtio_interface_tx_inline (vm, node, frame, vif, 1 /* do_gso */ );
+  if (hw->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO)
+    return virtio_interface_tx_inline (vm, node, frame, vif, 1 /* do_gso */ ,
+				       1);
+  else if (hw->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_TX_L4_CKSUM_OFFLOAD)
+    return virtio_interface_tx_inline (vm, node, frame, vif,
+				       0 /* no do_gso */ , 1);
   else
     return virtio_interface_tx_inline (vm, node, frame, vif,
-				       0 /* no do_gso */ );
+				       0 /* no do_gso */ , 0);
 }
 
 static void
diff --git a/src/vnet/devices/virtio/node.c b/src/vnet/devices/virtio/node.c
index ba17075d48c..d31fb144b8f 100644
--- a/src/vnet/devices/virtio/node.c
+++ b/src/vnet/devices/virtio/node.c
@@ -242,7 +242,7 @@ fill_gso_buffer_flags (vlib_buffer_t * b0, struct virtio_net_hdr_v1 *hdr,
 static_always_inline uword
 virtio_device_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 			    vlib_frame_t * frame, virtio_if_t * vif, u16 qid,
-			    int gso_enabled)
+			    int gso_enabled, int checksum_offload_enabled)
 {
   vnet_main_t *vnm = vnet_get_main ();
   u32 thread_index = vm->thread_index;
@@ -289,7 +289,8 @@ virtio_device_input_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
 	  b0->total_length_not_including_first_buffer = 0;
 	  b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
 
-	  virtio_needs_csum (b0, hdr, &l4_proto, &l4_hdr_sz);
+	  if (checksum_offload_enabled)
+	    virtio_needs_csum (b0, hdr, &l4_proto, &l4_hdr_sz);
 
 	  if (gso_enabled)
 	    fill_gso_buffer_flags (b0, hdr, l4_proto, l4_hdr_sz);
@@ -396,10 +397,13 @@ VLIB_NODE_FN (virtio_input_node) (vlib_main_t * vm,
       {
 	if (vif->gso_enabled)
 	  n_rx += virtio_device_input_inline (vm, node, frame, vif,
-					      dq->queue_id, 1);
+					      dq->queue_id, 1, 1);
+	else if (vif->csum_offload_enabled)
+	  n_rx += virtio_device_input_inline (vm, node, frame, vif,
+					      dq->queue_id, 0, 1);
 	else
 	  n_rx += virtio_device_input_inline (vm, node, frame, vif,
-					      dq->queue_id, 0);
+					      dq->queue_id, 0, 0);
       }
   }
 
diff --git a/src/vnet/devices/virtio/pci.c b/src/vnet/devices/virtio/pci.c
index ab21147aca9..c956e7b75fa 100644
--- a/src/vnet/devices/virtio/pci.c
+++ b/src/vnet/devices/virtio/pci.c
@@ -110,7 +110,7 @@ virtio_pci_legacy_write_config (vlib_main_t * vm, virtio_if_t * vif,
 }
 
 static u64
-virtio_pci_legacy_get_features (vlib_main_t * vm, virtio_if_t * vif)
+virtio_pci_legacy_get_host_features (vlib_main_t * vm, virtio_if_t * vif)
 {
   u32 features;
   vlib_pci_read_io_u32 (vm, vif->pci_dev_handle, VIRTIO_PCI_HOST_FEATURES,
@@ -119,8 +119,18 @@ virtio_pci_legacy_get_features (vlib_main_t * vm, virtio_if_t * vif)
 }
 
 static u32
-virtio_pci_legacy_set_features (vlib_main_t * vm, virtio_if_t * vif,
-				u64 features)
+virtio_pci_legacy_get_guest_features (vlib_main_t * vm, virtio_if_t * vif)
+{
+  u32 feature = 0;
+  vlib_pci_read_io_u32 (vm, vif->pci_dev_handle, VIRTIO_PCI_GUEST_FEATURES,
+			&feature);
+  vif->features = feature;
+  return feature;
+}
+
+static u32
+virtio_pci_legacy_set_guest_features (vlib_main_t * vm, virtio_if_t * vif,
+				      u64 features)
 {
   if ((features >> 32) != 0)
     {
@@ -555,6 +565,47 @@ virtio_pci_send_ctrl_msg (vlib_main_t * vm, virtio_if_t * vif,
 }
 
 static int
+virtio_pci_disable_offload (vlib_main_t * vm, virtio_if_t * vif)
+{
+  struct virtio_ctrl_msg offload_hdr;
+  virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
+
+  offload_hdr.ctrl.class = VIRTIO_NET_CTRL_GUEST_OFFLOADS;
+  offload_hdr.ctrl.cmd = VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET;
+  offload_hdr.status = VIRTIO_NET_ERR;
+  u64 offloads = 0ULL;
+  clib_memcpy (offload_hdr.data, &offloads, sizeof (offloads));
+
+  status =
+    virtio_pci_send_ctrl_msg (vm, vif, &offload_hdr, sizeof (offloads));
+  virtio_log_debug (vif, "disable offloads");
+  vif->remote_features = virtio_pci_legacy_get_host_features (vm, vif);
+  virtio_pci_legacy_get_guest_features (vm, vif);
+  return status;
+}
+
+static int
+virtio_pci_enable_checksum_offload (vlib_main_t * vm, virtio_if_t * vif)
+{
+  struct virtio_ctrl_msg csum_offload_hdr;
+  virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
+
+  csum_offload_hdr.ctrl.class = VIRTIO_NET_CTRL_GUEST_OFFLOADS;
+  csum_offload_hdr.ctrl.cmd = VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET;
+  csum_offload_hdr.status = VIRTIO_NET_ERR;
+  u64 offloads = 0ULL;
+  offloads |= VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_CSUM);
+  clib_memcpy (csum_offload_hdr.data, &offloads, sizeof (offloads));
+
+  status =
+    virtio_pci_send_ctrl_msg (vm, vif, &csum_offload_hdr, sizeof (offloads));
+  virtio_log_debug (vif, "enable checksum offload");
+  vif->remote_features = virtio_pci_legacy_get_host_features (vm, vif);
+  virtio_pci_legacy_get_guest_features (vm, vif);
+  return status;
+}
+
+static int
 virtio_pci_enable_gso (vlib_main_t * vm, virtio_if_t * vif)
 {
   struct virtio_ctrl_msg gso_hdr;
@@ -565,16 +616,78 @@ virtio_pci_enable_gso (vlib_main_t * vm, virtio_if_t * vif)
   gso_hdr.status = VIRTIO_NET_ERR;
   u64 offloads = VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_CSUM)
     | VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_TSO4)
-    | VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_TSO6)
-    | VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_UFO);
+    | VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_TSO6);
   clib_memcpy (gso_hdr.data, &offloads, sizeof (offloads));
 
   status = virtio_pci_send_ctrl_msg (vm, vif, &gso_hdr, sizeof (offloads));
   virtio_log_debug (vif, "enable gso");
+  vif->remote_features = virtio_pci_legacy_get_host_features (vm, vif);
+  virtio_pci_legacy_get_guest_features (vm, vif);
   return status;
 }
 
 static int
+virtio_pci_offloads (vlib_main_t * vm, virtio_if_t * vif, int gso_enabled,
+		     int csum_offload_enabled)
+{
+  vnet_main_t *vnm = vnet_get_main ();
+  vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, vif->hw_if_index);
+
+  if ((vif->features & VIRTIO_FEATURE (VIRTIO_NET_F_CTRL_VQ)) &&
+      (vif->features & VIRTIO_FEATURE (VIRTIO_NET_F_CTRL_GUEST_OFFLOADS)))
+    {
+      if (gso_enabled
+	  && (vif->features & (VIRTIO_FEATURE (VIRTIO_NET_F_HOST_TSO4) |
+			       VIRTIO_FEATURE (VIRTIO_NET_F_HOST_TSO6))))
+	{
+	  if (virtio_pci_enable_gso (vm, vif))
+	    {
+	      virtio_log_warning (vif, "gso is not enabled");
+	    }
+	  else
+	    {
+	      vif->gso_enabled = 1;
+	      vif->csum_offload_enabled = 0;
+	      hw->flags |= VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO |
+		VNET_HW_INTERFACE_FLAG_SUPPORTS_TX_L4_CKSUM_OFFLOAD;
+	    }
+	}
+      else if (csum_offload_enabled
+	       && (vif->features & VIRTIO_FEATURE (VIRTIO_NET_F_CSUM)))
+	{
+	  if (virtio_pci_enable_checksum_offload (vm, vif))
+	    {
+	      virtio_log_warning (vif, "checksum offload is not enabled");
+	    }
+	  else
+	    {
+	      vif->csum_offload_enabled = 1;
+	      vif->gso_enabled = 0;
+	      hw->flags &= ~VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO;
+	      hw->flags |=
+		VNET_HW_INTERFACE_FLAG_SUPPORTS_TX_L4_CKSUM_OFFLOAD;
+	    }
+	}
+      else
+	{
+	  if (virtio_pci_disable_offload (vm, vif))
+	    {
+	      virtio_log_warning (vif, "offloads are not disabled");
+	    }
+	  else
+	    {
+	      vif->csum_offload_enabled = 0;
+	      vif->gso_enabled = 0;
+	      hw->flags &= ~(VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO |
+			     VNET_HW_INTERFACE_FLAG_SUPPORTS_TX_L4_CKSUM_OFFLOAD);
+	    }
+	}
+    }
+
+  return 0;
+}
+
+static int
 virtio_pci_enable_multiqueue (vlib_main_t * vm, virtio_if_t * vif,
 			      u16 num_queues)
 {
@@ -770,13 +883,14 @@ virtio_negotiate_features (vlib_main_t * vm, virtio_if_t * vif,
 	vif->features &= ~VIRTIO_FEATURE (VIRTIO_NET_F_MTU);
     }
 
-  vif->features = virtio_pci_legacy_set_features (vm, vif, vif->features);
+  vif->features =
+    virtio_pci_legacy_set_guest_features (vm, vif, vif->features);
 }
 
 void
 virtio_pci_read_device_feature (vlib_main_t * vm, virtio_if_t * vif)
 {
-  vif->remote_features = virtio_pci_legacy_get_features (vm, vif);
+  vif->remote_features = virtio_pci_legacy_get_host_features (vm, vif);
 }
 
 int
@@ -1208,30 +1322,17 @@ virtio_pci_create_if (vlib_main_t * vm, virtio_pci_create_if_args_t * args)
   else
     vnet_hw_interface_set_flags (vnm, vif->hw_if_index, 0);
 
-  if (vif->features & VIRTIO_FEATURE (VIRTIO_NET_F_CTRL_VQ))
+  virtio_pci_offloads (vm, vif, args->gso_enabled,
+		       args->checksum_offload_enabled);
+
+  if ((vif->features & VIRTIO_FEATURE (VIRTIO_NET_F_CTRL_VQ)) &&
+      (vif->features & VIRTIO_FEATURE (VIRTIO_NET_F_MQ)))
     {
-      if (vif->features & VIRTIO_FEATURE (VIRTIO_NET_F_CTRL_GUEST_OFFLOADS) &&
-	  args->gso_enabled)
-	{
-	  if (virtio_pci_enable_gso (vm, vif))
-	    {
-	      virtio_log_warning (vif, "gso is not enabled");
-	    }
-	  else
-	    {
-	      vif->gso_enabled = 1;
-	      hw->flags |= VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO;
-	    }
-	}
-      if (vif->features & VIRTIO_FEATURE (VIRTIO_NET_F_MQ))
-	{
-	  if (virtio_pci_enable_multiqueue (vm, vif, vif->max_queue_pairs))
-	    virtio_log_warning (vif, "multiqueue is not set");
-	}
+      if (virtio_pci_enable_multiqueue (vm, vif, vif->max_queue_pairs))
+	virtio_log_warning (vif, "multiqueue is not set");
     }
   return;
 
-
 error:
   virtio_pci_delete_if (vm, vif);
   args->rv = VNET_API_ERROR_INVALID_INTERFACE;
@@ -1325,6 +1426,25 @@ virtio_pci_delete_if (vlib_main_t * vm, virtio_if_t * vif)
   return 0;
 }
 
+int
+virtio_pci_enable_disable_offloads (vlib_main_t * vm, virtio_if_t * vif,
+				    int gso_enabled,
+				    int checksum_offload_enabled,
+				    int offloads_disabled)
+{
+  if (vif->type != VIRTIO_IF_TYPE_PCI)
+    return VNET_API_ERROR_INVALID_INTERFACE;
+
+  if (gso_enabled)
+    virtio_pci_offloads (vm, vif, 1, 0);
+  else if (checksum_offload_enabled)
+    virtio_pci_offloads (vm, vif, 0, 1);
+  else if (offloads_disabled)
+    virtio_pci_offloads (vm, vif, 0, 0);
+
+  return 0;
+}
+
 /*
  * fd.io coding-style-patch-verification: ON
  *
diff --git a/src/vnet/devices/virtio/pci.h b/src/vnet/devices/virtio/pci.h
index 4c62885adbf..8ec1360bc59 100644
--- a/src/vnet/devices/virtio/pci.h
+++ b/src/vnet/devices/virtio/pci.h
@@ -225,6 +225,7 @@ typedef struct
   u8 mac_addr[6];
   u64 features;
   u8 gso_enabled;
+  u8 checksum_offload_enabled;
   clib_error_t *error;
 } virtio_pci_create_if_args_t;
 
@@ -233,7 +234,10 @@ extern void device_status (vlib_main_t * vm, virtio_if_t * vif);
 void virtio_pci_create_if (vlib_main_t * vm,
 			   virtio_pci_create_if_args_t * args);
 int virtio_pci_delete_if (vlib_main_t * vm, virtio_if_t * ad);
-
+int virtio_pci_enable_disable_offloads (vlib_main_t * vm, virtio_if_t * vif,
+					int gso_enabled,
+					int checksum_offload_enabled,
+					int offloads_disabled);
 #endif /* __included_virtio_pci_h__ */
 /*
  * fd.io coding-style-patch-verification: ON
diff --git a/src/vnet/devices/virtio/virtio.api b/src/vnet/devices/virtio/virtio.api
index b191810d71b..efbcba8fa43 100644
--- a/src/vnet/devices/virtio/virtio.api
+++ b/src/vnet/devices/virtio/virtio.api
@@ -27,6 +27,7 @@ import "vnet/pci/pci_types.api";
     @param use_random_mac - let the system generate a unique mac address
     @param mac_address - mac addr to assign to the interface if use_random not set
     @param gso_enabled - enable gso feature if available, 1 to enable
+    @param checksum_offload_enabled - enable checksum feature if available, 1 to enable
     @param features - the virtio features which driver should negotiate with device
 */
 define virtio_pci_create
@@ -37,6 +38,7 @@ define virtio_pci_create
   bool use_random_mac;
   vl_api_mac_address_t mac_address;
   bool gso_enabled;
+  bool checksum_offload_enabled;
   u64 features;
 };
 
diff --git a/src/vnet/devices/virtio/virtio.c b/src/vnet/devices/virtio/virtio.c
index d3a6e15ac56..6504b2ae762 100644
--- a/src/vnet/devices/virtio/virtio.c
+++ b/src/vnet/devices/virtio/virtio.c
@@ -288,6 +288,8 @@ virtio_show (vlib_main_t * vm, u32 * hw_if_indices, u8 show_descr, u32 type)
 	{
 	  vlib_cli_output (vm, "  PCI Address: %U", format_vlib_pci_addr,
 			   &vif->pci_addr);
+	  vlib_cli_output (vm, "  csum-enabled %d",
+			   vif->csum_offload_enabled);
 	}
       if (type == VIRTIO_IF_TYPE_TAP)
 	{
diff --git a/src/vnet/devices/virtio/virtio.h b/src/vnet/devices/virtio/virtio.h
index 27ecc2238ad..4b8662699da 100644
--- a/src/vnet/devices/virtio/virtio.h
+++ b/src/vnet/devices/virtio/virtio.h
@@ -174,6 +174,7 @@ typedef struct
   u8 host_ip6_prefix_len;
   u32 host_mtu_size;
   int gso_enabled;
+  int csum_offload_enabled;
   int ifindex;
   virtio_vring_t *cxq_vring;
 } virtio_if_t;
diff --git a/src/vnet/devices/virtio/virtio_api.c b/src/vnet/devices/virtio/virtio_api.c
index ac167e827c6..4d98e725fde 100644
--- a/src/vnet/devices/virtio/virtio_api.c
+++ b/src/vnet/devices/virtio/virtio_api.c
@@ -71,6 +71,11 @@ vl_api_virtio_pci_create_t_handler (vl_api_virtio_pci_create_t * mp)
     ap->gso_enabled = 1;
   else
     ap->gso_enabled = 0;
+  if (mp->checksum_offload_enabled)
+    ap->checksum_offload_enabled = 1;
+  else
+    ap->checksum_offload_enabled = 0;
+
   ap->features = clib_net_to_host_u64 (mp->features);
 
   virtio_pci_create_if (vm, ap);