Index: /trunk/src/VBox/Devices/Network/DevVirtioNet.cpp
===================================================================
--- /trunk/src/VBox/Devices/Network/DevVirtioNet.cpp	(revision 41819)
+++ /trunk/src/VBox/Devices/Network/DevVirtioNet.cpp	(revision 41820)
@@ -1141,11 +1141,14 @@
                                     pGso->cbHdrsTotal = Hdr.u16CSumStart +
                                         ((PRTNETTCP)(((uint8_t*)pSgBuf->aSegs[0].pvSeg) + Hdr.u16CSumStart))->th_off * 4;
+                                    pGso->cbHdrsSeg   = pGso->cbHdrsTotal;
                                     break;
                                 case PDMNETWORKGSOTYPE_IPV4_UDP:
                                     pGso->cbHdrsTotal = Hdr.u16CSumStart + sizeof(RTNETUDP);
+                                    pGso->cbHdrsSeg   = Hdr.u16CSumStart;
                                     break;
                             }
                             /* Update GSO structure embedded into the frame */
                             ((PPDMNETWORKGSO)pSgBuf->pvUser)->cbHdrsTotal = pGso->cbHdrsTotal;
+                            ((PPDMNETWORKGSO)pSgBuf->pvUser)->cbHdrsSeg   = pGso->cbHdrsTotal;
                             Log4(("%s vnetTransmitPendingPackets: adjusted HdrLen to %d.\n",
                                   INSTANCE(pState), pGso->cbHdrsTotal));