Re: [dpdk-dev] [PATCH] doc: announce ABI change for rte_eth_dev structure

[Thomas Monjalon <thomas.monjalon@6wind.com>]

2016-07-20 15:13, Ananyev, Konstantin:
> Hi Thomas,
> 
> > Hi,
> > 
> > This patch announces an interesting change in the DPDK design.
> > 
> > 2016-07-20 16:24, Tomasz Kulasek:
> > > This is an ABI deprecation notice for DPDK 16.11 in librte_ether about
> > > changes in rte_eth_dev and rte_eth_desc_lim structures.
> > >
> > > In 16.11, we plan to introduce rte_eth_tx_prep() function to do
> > > necessary preparations of packet burst to be safely transmitted on
> > > device for desired HW offloads (set/reset checksum field according to
> > > the hardware requirements) and check HW constraints (number of
> > > segments per packet, etc).
> > >
> > > While the limitations and requirements may differ for devices, it
> > > requires to extend rte_eth_dev structure with new function pointer
> > > "tx_pkt_prep" which can be implemented in the driver to prepare and
> > > verify packets, in devices specific way, before burst, what should to
> > > prevent application to send malformed packets.
> > >
> > > Also new fields will be introduced in rte_eth_desc_lim: nb_seg_max and
> > > nb_mtu_seg_max, providing an information about max segments in TSO and
> > > non TSO packets acceptable by device.
> > 
> > We cannot acknowledge such notice without a prior design discussion.
> > Please explain why you plan to work on this change and give a draft of the new structures (a RFC patch would be ideal).
> 
> I think it is not really a deprecation note, but announce ABI change for rte_ethdev.h structures.

An ABI break requires a deprecation notice. So it is :)

> The plan is to implement what was proposed & discussed the following thread:
> http://dpdk.org/ml/archives/dev/2015-September/023603.html

Please could you summarize it here?