>-----Original Message-----
>From: 仇大玉 [mailto:[email protected]]
>Sent: Tuesday, June 27, 2017 3:31 AM
>To: Kavanagh, Mark B <[email protected]>; Michael Qiu
><[email protected]>; [email protected]
>Cc: [email protected]; [email protected]
>Subject: Re: [PATCH 2/5] lib/dp-packet: copy additional packet info when do
>packet copy
>
>
>
>在 2017/6/26 23:07, Kavanagh, Mark B 写道:
>>> From: Michael Qiu [mailto:[email protected]]
>>> Sent: Monday, June 19, 2017 6:29 AM
>>> To: [email protected]
>>> Cc: Kavanagh, Mark B <[email protected]>; [email protected];
>[email protected]; Michael Qiu
>>> <[email protected]>
>>> Subject: [PATCH 2/5] lib/dp-packet: copy additional packet info when do
>packet copy
>>>
>>> From: Michael Qiu <[email protected]>
>>>
>>> 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 <[email protected]>
>>> ---
>>> 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 ee2c449..9f872a1 100644
>>> --- a/lib/dp-packet.c
>>> +++ b/lib/dp-packet.c
>>> @@ -179,6 +179,9 @@ dp_packet_clone_with_headroom(const struct dp_packet
>*buffer, size_t
>>> headroom)
>>> new_buffer->packet_type = buffer->packet_type;
>>> #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;
>> Hi Michael,
>>
>> In what use case would this information be useful?
>>
>> Mirroring, perhaps?
>
>When doing offloading, we need tx_offload flag(although upstream does
>not support yet), also when doing packet copy, we need nb_segs field.
Yes, I understand that; I guess what I was really asking is 'what is the series
of actions for which this information would be useful?'.
Looking at the code, my guess is that the info is relevant when a packet (which
is marked for some form of offload) is cloned (odp_execute_clone), and that
cloned packet is sent out to a phy port (via odp_execute_actions).
>
>>
>>> #else
>>> new_buffer->rss_hash_valid = buffer->rss_hash_valid;
>>> #endif
>>> diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
>>> index bba4de3..0485872 100644
>>> --- a/lib/netdev-dpdk.c
>>> +++ b/lib/netdev-dpdk.c
>>> @@ -1804,6 +1804,10 @@ dpdk_do_tx_copy(struct netdev *netdev, int qid,
>struct dp_packet_batch
>>> *batch)
>>> memcpy(rte_pktmbuf_mtod(pkts[newcnt], void *),
>>> dp_packet_data(batch->packets[i]), size);
>>>
>>> + pkts[newcnt]->nb_segs = batch->packets[i]->mbuf.nb_segs;
>>> + pkts[newcnt]->ol_flags = batch->packets[i]->mbuf.ol_flags;
>>> + pkts[newcnt]->packet_type = batch->packets[i]->mbuf.packet_type;
>>> + pkts[newcnt]->tx_offload = batch->packets[i]->mbuf.tx_offload;
>> Could you give an example of when it would be useful to copy info from mbufs
>which originate from non-DPDK source?
>> AFIA, non-DPDK sources don't currently update these particular fields - if
>I've missed something though, please let me know.
>
>What happens when a packet from DPDK be copied twice?
>DPDK(VM virtio)--(flooding)->non-DPDK(patch port)--(copy)->DPDK(NIC)?
Perfect - that makes sense.
>
>
>>
>>> rte_pktmbuf_data_len(pkts[newcnt]) = size;
>>> rte_pktmbuf_pkt_len(pkts[newcnt]) = size;
>>>
>>> --
>>> 1.8.3.1
>>
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