[dpdk-dev] [PATCH v8 10/10] app/testpmd:test VxLAN Tx checksum offload

[Liu, Jijiang]

> -----Original Message-----
> From: Olivier MATZ [mailto:olivier.matz at 6wind.com]
> Sent: Tuesday, November 11, 2014 12:17 AM
> To: Liu, Jijiang
> Cc: dev at dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v8 10/10] app/testpmd:test VxLAN Tx checksum
> offload
> 
> Hi Jijiang,
> 
> On 11/10/2014 07:03 AM, Liu, Jijiang wrote:
> >> Another thing is surprising me.
> >>
> >> - if PKT_TX_VXLAN_CKSUM is not set (legacy use case), then the
> >>    driver use l2_len and l3_len to offload inner IP/UDP/TCP checksums.
> > If the flag is not set, and imply that it is not VXLAN packet,  and do
> > TX checksum offload as regular packet.
> >
> >> - if PKT_TX_VXLAN_CKSUM is set, then the driver has to use
> >>    inner_l{23}_len instead of l{23}_len for the same operation.
> > Your understanding is not fully correct.
> > The l{23}_len is still used for TX checksum offload, please refer to
> i40e_txd_enable_checksum()  implementation.
> 
> This fields are part of public mbuf API. You cannot say to refer to i40e PMD code
> to understand how to use it.
> 
> >> Adding PKT_TX_VXLAN_CKSUM changes the semantic of l2_len and l3_len.
> >> To fix this, I suggest to remove the new fields inner_l{23}_len then
> >> add outer_l{23}_len instead. Therefore, the semantic of l2_len and
> >> l3_len would not change, and a driver would always use the same field for a
> specific offload.
> > Oh...
> 
> Does it mean you agree?

I don't agree to change inner_l{23}_len the name.
The reason is that using the "inner" word means  incoming  packet is tunneling packet or encapsulation packet.
if we add  "outer"{2,3}_len  , which will cause confusion when processing non-tunneling packet.


> >> For my TSO development, I will follow the current semantic.
> > For TSO, you still can use l{2,3} _len .
> > When I develop tunneling TSO, I will use inner_l3_len/inner_l4_len.
> 
> I've just submitted a first version, please feel free to comment it.
> 
> 
> Regards,
> Olivier