e1000e: Perform software segmentation for loopback

e1000e didn't perform software segmentation for loopback if virtio-net
header is enabled, which is wrong.

To fix the problem, introduce net_tx_pkt_send_custom(), which allows the
caller to specify whether offloading should be assumed or not.

net_tx_pkt_send_custom() also allows the caller to provide a custom
sending function. Packets with virtio-net headers and ones without
virtio-net headers will be provided at the same time so the function
can choose the preferred version. In case of e1000e loopback, it prefers
to have virtio-net headers as they allows to skip the checksum
verification if VIRTIO_NET_HDR_F_DATA_VALID is set.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

1 files changed, 12 insertions, 9 deletions

diff --git a/hw/net/net_tx_pkt.h b/hw/net/net_tx_pkt.h
index 8d3faa42fb..f57b4e034b 100644
--- a/hw/net/net_tx_pkt.h
+++ b/hw/net/net_tx_pkt.h
@@ -26,6 +26,8 @@
 
 struct NetTxPkt;
 
+typedef void (* NetTxPktCallback)(void *, const struct iovec *, int, const struct iovec *, int);
+
 /**
  * Init function for tx packet functionality
  *
@@ -161,15 +163,16 @@ void net_tx_pkt_reset(struct NetTxPkt *pkt);
 bool net_tx_pkt_send(struct NetTxPkt *pkt, NetClientState *nc);
 
 /**
-* Redirect packet directly to receive path (emulate loopback phy).
-* Handles sw offloads if vhdr is not supported.
-*
-* @pkt:            packet
-* @nc:             NetClientState
-* @ret:            operation result
-*
-*/
-bool net_tx_pkt_send_loopback(struct NetTxPkt *pkt, NetClientState *nc);
+ * Send packet with a custom function.
+ *
+ * @pkt:            packet
+ * @offload:        whether the callback implements offloading
+ * @callback:       a function to be called back for each transformed packet
+ * @context:        a pointer to be passed to the callback.
+ * @ret:            operation result
+ */
+bool net_tx_pkt_send_custom(struct NetTxPkt *pkt, bool offload,
+                            NetTxPktCallback callback, void *context);
 
 /**
  * parse raw packet data and analyze offload requirements.