[ovs-dev] [PATCH 2/5] lib/dp-packet: copy additional packet info when do packet copy

[Michael Qiu]

2016/10/28 17:47, Kavanagh, Mark B :
>> Currently, when doing packet copy, lots of DPDK mbuf's info
>> will be missed, like packet type, ol_flags, etc.
>> Those information is very important for DPDK to do
>> packets processing.
>>
>> Signed-off-by: Michael Qiu <qiudayu at chinac.com>
>> Signed-off-by: Jijiang Liu <liujijiang at chinac.com>
>> ---
>> lib/dp-packet.c   | 3 +++
>> lib/netdev-dpdk.c | 4 ++++
>> 2 files changed, 7 insertions(+)
>>
>> diff --git a/lib/dp-packet.c b/lib/dp-packet.c
>> index bf8522e..619f651 100644
>> --- a/lib/dp-packet.c
>> +++ b/lib/dp-packet.c
>> @@ -175,6 +175,9 @@ dp_packet_clone_with_headroom(const struct dp_packet *buffer, size_t
>> headroom)
>>      new_buffer->cutlen = buffer->cutlen;
>> #ifdef DPDK_NETDEV
>>      new_buffer->mbuf.ol_flags = buffer->mbuf.ol_flags;
>> +    new_buffer->mbuf.tx_offload = buffer->mbuf.tx_offload;
>> +    new_buffer->mbuf.packet_type = buffer->mbuf.packet_type;
>> +    new_buffer->mbuf.nb_segs = buffer->mbuf.nb_segs;
>> #else
>>      new_buffer->rss_hash_valid = buffer->rss_hash_valid;
>> #endif
>> diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
> This doesn't apply cleanly for me - apply change described below to resolve.

Hi, Mark

Sorry, my patchset is based on version tag 2.6, I will make V2 patch 
which based on the latest code.

>> index 27b4ee2..ad92504 100644
>> --- a/lib/netdev-dpdk.c
>> +++ b/lib/netdev-dpdk.c
>> @@ -1589,6 +1589,10 @@ dpdk_do_tx_copy(struct netdev *netdev, int qid, struct dp_packet_batch
>> *batch)
>>          memcpy(rte_pktmbuf_mtod(mbufs[newcnt], void *),
>>                 dp_packet_data(batch->packets[i]), size);
>>
>> +        mbufs[newcnt]->nb_segs = batch->packets[i]->mbuf.nb_segs;
>> +        mbufs[newcnt]->ol_flags = batch->packets[i]->mbuf.ol_flags;
>> +        mbufs[newcnt]->packet_type = batch->packets[i]->mbuf.packet_type;
> I'm not sure if this change is needed; mbuf->packet_type is only useful on the NIC Rx path, right? Please let me know if I've missed something.

Yes, you are right.  There are two reasons:

First, it does no harm when we copy it in tx path, at least, I haven't 
found any, if I'm wrong, show me please.

Second, we could reuse this field to carry tunnel info(tun_type) when do 
header push, thus in dpdk tx path, we could easily get the packet's 
tunnel info like vxlan, IPIP, GRE, etc. and do the tunnel offloads settings.

>
>> +        mbufs[newcnt]->tx_offload = batch->packets[i]->mbuf.tx_offload;
>>          rte_pktmbuf_data_len(mbufs[newcnt]) = size;
>>          rte_pktmbuf_pkt_len(mbufs[newcnt]) = size;
> The mbuf array is named 'pkts' as opposed to 'mbufs' in the latest upstream codebase; renaming the array allows the patch to apply cleanly.

OK, I will post the newest code to fix this.

>> --
>> 1.8.3.1
>