[ovs-dev] [PATCH v2] datapath-windows: Improved offloading on STT tunnel

[Alin Serdean]

> >-    UINT32 encapMss = OvsGetExternalMtu(switchContext) - sizeof(IPHdr) -
> >sizeof(TCPHdr);
> >+    UINT32 encapMss = OvsGetExternalMtu(switchContext)
> >+                      - sizeof(IPHdr)
> >+                      - sizeof(TCPHdr);
> >     if (ipTotalLen > encapMss) {
> >-        lsoInfo.Value = 0;
> >-        lsoInfo.LsoV2Transmit.TcpHeaderOffset = tcpHeaderOffset;
> >-        lsoInfo.LsoV2Transmit.MSS = encapMss;
> >-        lsoInfo.LsoV2Transmit.Type =
> NDIS_TCP_LARGE_SEND_OFFLOAD_V2_TYPE;
> >-        lsoInfo.LsoV2Transmit.IPVersion =
> >NDIS_TCP_LARGE_SEND_OFFLOAD_IPv4;
> >+        outerIpHdr->check = IPChecksum((UINT8 *)outerIpHdr,
> >+                                       sizeof *outerIpHdr, 0);
> >+        outerTcpHdr->check = IPPseudoChecksum(&fwdInfo->srcIpAddr,
> >+                                              (uint32 *) &tunKey->dst,
> >+                                              IPPROTO_TCP, (uint16)
> >+ 0);
> >+
> 
> Sai: We discussed about this in the Hyper-V IRC meeting. You can get rid of
> the V1 type since we can¹t enforce the type of an inner VM on outer host.
> 
[Alin Gabriel Serdean: ] My question would be the following. What happens if the miniport (the actual host adapter) does not support LSO V2.

Alin.