Re: [dpdk-dev] [PATCH] net/tap: remove queue specific offload support

[Ophir Munk <ophirmu@mellanox.com>]

Hi Ferruh,
A quick feedback to your patch on top of next-net/master: the IP and TCP offloaded checksums are turned incorrect.

Detailed description
================
A traffic generator is sending to a dpdk device one TCP packet and expects to receive it back after the IP and TCP checksums have been calculated by TAP.

Testpmd parameters
=================
testpmd -c 0x0f -n 4 --vdev="net_tap0,iface=net_vsc0,remote=ens2" -w 0000:00:00.0 -- --burst=64 --mbcache=512 --portmask 0x1 -i --txd=256 --rxd=256 --rxq=1 --txq=1 --coremask 0x008  --forward-mode=csum  --eth-peer=0,00:15:5d:10:66:02

Testpmd CLI commands
===================
testpmd> port stop all
testpmd> csum set ip hw 0
testpmd> csum set tcp hw 0
testpmd> port start all
testpmd> start

On Traffic generator side
=====================
A traffic generator (scapy) is sending 1261 bytes of a TCP packet

Monitoring the traffic:

tcpdump -i <interface name> -envvv &

The tcpdump output shows the sent packet followed by the received packet. 
Please note the received packet has incorrect IP & TCP checksums (both are 0)

11:51:03.058623 00:15:5d:10:66:02 > f4:52:14:7a:59:81, ethertype IPv4 (0x0800), length 1261: (tos 0x0, ttl 64, id 1, offset 0, flags [none], proto TCP (6), length 1247)
    127.0.0.1.1 > 127.0.0.1.1: Flags [S], cksum 0xdba5 (correct), seq 0:1207, win 8192, length 1207

11:51:03.058836 f4:52:14:7a:59:81 > 00:15:5d:10:66:02, ethertype IPv4 (0x0800), length 1261: (tos 0x0, ttl 64, id 1, offset 0, flags [none], proto TCP (6), length 1247, bad cksum 0 (->7816)!)
    127.0.0.1.1 > 127.0.0.1.1: Flags [S], cksum 0x0000 (incorrect -> 0xdba5), seq 0:1207, win 8192, length 1207

Regards,
Ophir

> -----Original Message-----
> From: Ophir Munk
> Sent: Monday, April 23, 2018 11:39 AM
> To: 'Ferruh Yigit' <ferruh.yigit@intel.com>; Thomas Monjalon
> <thomas@monjalon.net>; Pascal Mazon <pascal.mazon@6wind.com>;
> Mordechay Haimovsky <motih@mellanox.com>
> Cc: 'dev@dpdk.org' <dev@dpdk.org>; Shahaf Shuler
> <shahafs@mellanox.com>; Olga Shern <olgas@mellanox.com>; Raslan
> Darawsheh <rasland@mellanox.com>
> Subject: RE: [dpdk-dev] [PATCH] net/tap: remove queue specific offload
> support
> 
> Hi Ferruh,
> I was able to apply your patch with Thomas help:
> 1. git am --reject
> 2. <Fix code manually using *.rej file>
> 3. git am --continue
> 
> Regards,
> Ophir
> 
> > -----Original Message-----
> > From: Ophir Munk
> > Sent: Sunday, April 22, 2018 7:05 PM
> > To: Ferruh Yigit <ferruh.yigit@intel.com>; Thomas Monjalon
> > <thomas@monjalon.net>; Pascal Mazon <pascal.mazon@6wind.com>;
> > Mordechay Haimovsky <motih@mellanox.com>
> > Cc: dev@dpdk.org; Shahaf Shuler <shahafs@mellanox.com>; Olga Shern
> > <olgas@mellanox.com>; Raslan Darawsheh <rasland@mellanox.com>
> > Subject: RE: [dpdk-dev] [PATCH] net/tap: remove queue specific offload
> > support
> >
> > Hi Ferruh,
> > I am not able to apply your patch on next-net/master branch.
> > I am failing to apply it both on latest commit or just before
> > 22-Mar-18 (commit's date).
> >
> > $ git am dpdk-dev-net-tap-remove-queue-specific-offload-support.patch
> > Applying: net/tap: remove queue specific offload support
> > error: patch failed: drivers/net/tap/rte_eth_tap.c:269
> > error: drivers/net/tap/rte_eth_tap.c: patch does not apply Patch
> > failed at
> > 0001 net/tap: remove queue specific offload support
> >
> > Please advise.
> >
> > Once this error is fixed I can verify your patch with high priority
> > and send you my feedback.
> >
> > Regards,
> > Ophir
> >
> > > -----Original Message-----
> > > From: Ferruh Yigit [mailto:ferruh.yigit@intel.com]
> > > Sent: Wednesday, April 18, 2018 1:55 PM
> > > To: Ophir Munk <ophirmu@mellanox.com>; Thomas Monjalon
> > > <thomas@monjalon.net>; Pascal Mazon <pascal.mazon@6wind.com>;
> > > Mordechay Haimovsky <motih@mellanox.com>
> > > Cc: dev@dpdk.org; Shahaf Shuler <shahafs@mellanox.com>; Olga Shern
> > > <olgas@mellanox.com>
> > > Subject: Re: [dpdk-dev] [PATCH] net/tap: remove queue specific
> > > offload support
> > >
> > > On 4/18/2018 10:40 AM, Ophir Munk wrote:
> > > > Hi Ferruh,
> > > > Sorry for the delayed response.
> > > >
> > > > I would like to verify the correctness of this patch by running
> > > > several
> > > internal tests.
> > > > Is a reply by Monday OK with you?
> > >
> > > Monday can be late to include patch into rc1, any chance to do earlier?
> > >
> > > >
> > > > Regards,
> > > > Ophir
> > > >
> > > >> -----Original Message-----
> > > >> From: Ferruh Yigit [mailto:ferruh.yigit@intel.com]
> > > >> Sent: Wednesday, April 18, 2018 11:59 AM
> > > >> To: Thomas Monjalon <thomas@monjalon.net>; Pascal Mazon
> > > >> <pascal.mazon@6wind.com>; Mordechay Haimovsky
> > > <motih@mellanox.com>;
> > > >> Ophir Munk <ophirmu@mellanox.com>
> > > >> Cc: dev@dpdk.org; Shahaf Shuler <shahafs@mellanox.com>; Olga
> > > >> Shern <olgas@mellanox.com>
> > > >> Subject: Re: [dpdk-dev] [PATCH] net/tap: remove queue specific
> > > >> offload support
> > > >>
> > > >> On 4/12/2018 5:23 PM, Ferruh Yigit wrote:
> > > >>> On 4/5/2018 6:49 PM, Thomas Monjalon wrote:
> > > >>>> Pascal, Moti, Ophir,
> > > >>>> please comment.
> > > >>>
> > > >>> Hi Moti,
> > > >>>
> > > >>> Any comment? This has been asked many times now.
> > > >>
> > > >> Hi Moti, Ophir,
> > > >>
> > > >> You have not responded why queue specific offload added in other
> > > thread.
> > > >> And you are not responding to this patch...
> > > >>
> > > >> Hi Pascal,
> > > >>
> > > >> If you also have no objection, this patch is going in.
> > > >>
> > > >> Thanks,
> > > >> ferruh
> > > >>
> > > >>
> > > >>>
> > > >>>>
> > > >>>> 22/03/2018 19:28, Ferruh Yigit:
> > > >>>>> It is not clear if tap PMD supports queue specific offloads,
> > > >>>>> removing the related code.
> > > >>>>>
> > > >>>>> Fixes: 95ae196ae10b ("net/tap: use new Rx offloads API")
> > > >>>>> Fixes: 818fe14a9891 ("net/tap: use new Tx offloads API")
> > > >>>>> Cc: motih@mellanox.com
> > > >>>>>
> > > >>>>> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
> > > >>>>
> > > >>>>
> > > >>>>
> > > >>>
> > > >