datapath: Enable offloading on internal devices.

[sliver-openvswitch.git] / datapath / datapath.c

diff --git a/datapath/datapath.c b/datapath/datapath.c
index 71a44e6..79a1f63 100644 (file)
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -522,7 +522,6 @@ void dp_process_received_packet(struct dp_port *p, struct sk_buff *skb)
        skb_warn_if_lro(skb);
 
        OVS_CB(skb)->dp_port = p;
-       compute_ip_summed(skb, false);
 
        /* BHs are off so we don't have to use get_cpu()/put_cpu() here. */
        stats = percpu_ptr(dp->stats_percpu, smp_processor_id());
@@ -625,8 +624,7 @@ out:
  *     be computed if it is sent off box.  Unfortunately on earlier kernels,
  *     this case is impossible to distinguish from #2, despite having opposite
  *     meanings.  Xen adds an extra field on earlier kernels (see #4) in order
- *     to distinguish the different states.  The only real user of this type
- *     with bridging is Xen (on later kernels).
+ *     to distinguish the different states.
  * 4. CHECKSUM_UNNECESSARY (with proto_csum_blank true): This packet was
  *     generated locally by a Xen DomU and has a partial checksum.  If it is
  *     handled on this machine (Dom0 or DomU), then the checksum will not be
@@ -650,12 +648,7 @@ out:
  * packet is processed by the local IP stack, in which case it will need to
  * be reverified).  If we receive a packet with CHECKSUM_HW that really means
  * CHECKSUM_PARTIAL, it will be sent with the wrong checksum.  However, there
- * shouldn't be any devices that do this with bridging.
- *
- * The bridge has similar behavior and this function closely resembles
- * skb_forward_csum().  It is slightly different because we are only concerned
- * with bridging and not other types of forwarding and can get away with
- * slightly more optimal behavior.*/
+ * shouldn't be any devices that do this with bridging. */
 void
 compute_ip_summed(struct sk_buff *skb, bool xmit)
 {
@@ -670,14 +663,14 @@ compute_ip_summed(struct sk_buff *skb, bool xmit)
                break;
 #ifdef CHECKSUM_HW
        /* In theory this could be either CHECKSUM_PARTIAL or CHECKSUM_COMPLETE.
-        * However, we should only get CHECKSUM_PARTIAL packets from Xen, which
-        * uses some special fields to represent this (see below).  Since we
-        * can only make one type work, pick the one that actually happens in
-        * practice.
+        * However, on the receive side we should only get CHECKSUM_PARTIAL
+        * packets from Xen, which uses some special fields to represent this
+        * (see below).  Since we can only make one type work, pick the one
+        * that actually happens in practice.
         *
-        * The one exception to this is if we are on the transmit path
-        * (basically after skb_checksum_setup() has been run) the type has
-        * already been converted, so we should stay with that. */
+        * On the transmit side (basically after skb_checksum_setup()
+        * has been run or on internal dev transmit), packets with
+        * CHECKSUM_COMPLETE aren't generated, so assume CHECKSUM_PARTIAL. */
        case CHECKSUM_HW:
                if (!xmit)
                        OVS_CB(skb)->ip_summed = OVS_CSUM_COMPLETE;
@@ -710,6 +703,10 @@ compute_ip_summed(struct sk_buff *skb, bool xmit)
 #endif
 }
 
+/* This function closely resembles skb_forward_csum() used by the bridge.  It
+ * is slightly different because we are only concerned with bridging and not
+ * other types of forwarding and can get away with slightly more optimal
+ * behavior.*/
 void
 forward_ip_summed(struct sk_buff *skb)
 {
@@ -741,9 +738,7 @@ queue_control_packets(struct sk_buff *skb, struct sk_buff_head *queue,
                skb->next = NULL;
 
                /* If a checksum-deferred packet is forwarded to the
-                * controller, correct the pointers and checksum.  This happens
-                * on a regular basis only on Xen, on which VMs can pass up
-                * packets that do not have their checksum computed.
+                * controller, correct the pointers and checksum.
                 */
                err = vswitch_skb_checksum_setup(skb);
                if (err)