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Date:      Sat, 6 Jun 2020 09:52:31 +0200
From:      Vincenzo Maffione <vmaffione@freebsd.org>
To:        Anthony Arnaud <antho.arnaudisce@gmail.com>
Cc:        Luigi Rizzo <rizzo@iet.unipi.it>, "freebsd-net@freebsd.org" <freebsd-net@freebsd.org>
Subject:   Re: Netmap - Vale switch - tcp problem
Message-ID:  <CA%2B_eA9hi3FECs_u%2Bx_051HHxJqAggLx7KcbL_N5nvMXTPVc-vg@mail.gmail.com>
In-Reply-To: <CAGCUUMGJ2XSXFWMqL9TfCH7d6fTScF4s3u%2BwkbC1sqtPyFvqeA@mail.gmail.com>
References:  <CAGCUUMGxxiv8j-W3S8Gs1g=ZbDLnU8_Hv6SVMCpmnrRXPNsUTA@mail.gmail.com> <CA%2BhQ2%2BhfDvKv8q%2BjUB-mv_TaUTHfTPabx-qem-0=PW3vu8Br=A@mail.gmail.com> <CAGCUUMHwRghU3AMgKhQNrUs248y=NaGFN2Fm-f4khqhRsWn-qg@mail.gmail.com> <CA%2B_eA9iukqVoDZFyyW2qEZ2OHfE9=fUj070uUXcYmrXt67mwqw@mail.gmail.com> <CAGCUUMG7HG%2B8X89AYrhQ4dh6-equsvOLNyn_3sNU8h55PjPv9A@mail.gmail.com> <CA%2B_eA9j9zTM2JwCeMy6FmJQJmorVzXns2ijFgjuXa%2BrRQH400A@mail.gmail.com> <CAGCUUMEtuk4GW-7O%2B_XNcsh%2Bfrzu2O8ZBR_7SDQ-ir=L-dk0rw@mail.gmail.com> <CA%2B_eA9h%2B-z6mGCERK2_3fqCforqy5f8-caNsDKF0r1GF%2BkOfSQ@mail.gmail.com> <CA%2B_eA9hupv0JG7Q_LXUg7-StcEr=buLbBcJdvm1WRFy5PYqPUQ@mail.gmail.com> <CAGCUUMGJ2XSXFWMqL9TfCH7d6fTScF4s3u%2BwkbC1sqtPyFvqeA@mail.gmail.com>

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Il giorno ven 5 giu 2020 alle ore 18:16 Anthony Arnaud <
antho.arnaudisce@gmail.com> ha scritto:

> Hi Vincenzo,
> Thank you for your answers.
> I upgraded a guest machine in proxmox env to FreeBSD 13.0-CURRENT #0
> r361830.
> After that I compiled the tools as usual from /src/tools/tools/netmap
> I configured 2 NIC vtnet
>
> vtnet0 with an ip 192.168.1.x
> vtnet1 without ip and csum disabled as mirror of vtnet0 (using Open
> vSwitch)
> Tcp traffic is generated by an ssh connection from my host to guest
> machine.
>

Not clear where you run OVS. In the host or in the guest?


> "tcpdump -i vtnet1 tcp": at each keypress in ssh shell connected to
> 192.168.1.x I see few tcp packet sniffed in guest machine.
> But if I attach vtnet1 to vale switch, tcpdump no longer works as before.
> No tcp traffic is shown.
> Can I perform any other test about this?
>

First, have you tried to leave vtnet1 alone and try:

# ifconfig vtnet0 up 192.168.1.x -txcsum -rxcsum -tso4 -tso6
# vale-ctl -h vale0:vtnet0
and verified that you can ssh into 192.168.1.x from the host?

At least you verify that the vale-ctl -h works also on your enivironment.

Cheers,
  Vincenzo


> Cheers,
> Antho
>
> Il giorno mer 3 giu 2020 alle ore 19:53 Vincenzo Maffione <
> vmaffione@freebsd.org> ha scritto:
>
>> Hi Anthony,
>>   I fixed more bugs in the vtnet driver (in FreeBSD-CURRENT). As of
>> r361760, I'm now able to run the following steps in a VM with a vtnet device
>>
>> # ifconfig vtnet0 -txcsum -rxcsum -tso4 192.168.100.2/24
>> # vale-ctl -h vale:vtnet0
>> # netperf -H 192.168.100.1  # Run a netperf TCP_STREAM test to the host
>> bridge interface (br0)
>>
>> Since TCP works correctly at reasonable speed I'm confident that most of
>> the existing problems have gone.
>> Let me know if you have any questions about this.
>>
>> Cheers,
>>   Vincenzo
>>
>> Il giorno lun 1 giu 2020 alle ore 18:22 Vincenzo Maffione <
>> vmaffione@freebsd.org> ha scritto:
>>
>>> Hi Anthony,
>>>   I think there is more than a bug, drivers-related, that show up when
>>> you attach the interface to a vale switch.
>>> I've found and fixed some related to if_vtnet (see below). In any case,
>>> in my tests there is no difference between TCP traffic and other (UDP,
>>> ICMP, STP,...).
>>> The issues are not related to LRO, as I thought.
>>> There are still more bugs in vtnet and I'm trying to chase them.
>>> In the meanwhile it would help if you apply the patches below and try
>>> again with vtnet to see if the situation improves. They apply cleanly to
>>> 12.1 release.
>>>
>>> Regarding your problem with em devices, it is probably yet a different
>>> issue. It may be related to the iflib transition or not. It would help to
>>> try the same setup on stable/11 (which does not have iflib). I don't have
>>> an em device, but I will try with an emulated em in QEMU/KVM.
>>>
>>> Cheers,
>>>   Vincenzo
>>>
>>> ------------------------------------------------------------------------
>>> r361698 | vmaffione | 2020-06-01 16:14:29 +0000 (Mon, 01 Jun 2020) | 8
>>> lines
>>>
>>> netmap: if_vtnet: avoid netmap ring wraparound
>>>
>>> netmap assumes the one "slot" is left unused to distinguish
>>> the empty ring and full ring conditions. This assumption was
>>> violated by vtnet_netmap_rxq_populate().
>>>
>>> MFC after:      1 week
>>>
>>> ------------------------------------------------------------------------
>>> r361697 | vmaffione | 2020-06-01 16:12:09 +0000 (Mon, 01 Jun 2020) | 8
>>> lines
>>>
>>> netmap: if_vtnet: replace vtnet_free_used()
>>>
>>> The functionality contained in this function is duplicated,
>>> as it is already available in vtnet_txq_free_mbufs()
>>> and vtnet_rxq_free_mbufs().
>>>
>>> MFC after:      1 week
>>>
>>> ------------------------------------------------------------------------
>>> r361696 | vmaffione | 2020-06-01 16:10:44 +0000 (Mon, 01 Jun 2020) | 13
>>> lines
>>>
>>> netmap: vtnet: fix RX virtqueue initialization bug
>>>
>>> The vtnet_netmap_rxq_populate() function erroneously assumed
>>> that kring->nr_hwcur = 0, i.e. the kring was in the initial
>>> state. However, this is not always the case: for example,
>>> when a vtnet reinit is triggered by some changes in the
>>> interface flags or capenable.
>>> This patch changes the behaviour of vtnet_netmap_kring_refill()
>>> so that it always starts publishing the netmap buffers starting
>>> from the current value of kring->nr_hwcur.
>>>
>>> MFC after:      1 week
>>> ------------------------------------------------------------------------
>>> Il giorno lun 1 giu 2020 alle ore 15:19 Anthony Arnaud <
>>> antho.arnaudisce@gmail.com> ha scritto:
>>>
>>>> Hi Vincenzo,
>>>>
>>>> To simplify the scenario I have installed from scratch FBSD12.1 on a
>>>> new machine, without any virtualization env.
>>>> I have encountered the same problem, when i attach an ethernet
>>>> interface to vale switch (in this case an intel card em5) the tcp traffic
>>>> disappears and tcpdump shown only udp, icmp6 and stp packets.
>>>> If I detach the NIC from vale0 tcpdump shown all tcp traffic.
>>>> I'm using the netmap version included in FBSD 12.1, and I have compiled
>>>> vale-ctl presents in kernel sources (/src/tools/tools/netmap/)
>>>> I executed your steps.
>>>> There is something dark about that behaviour...
>>>>
>>>> Cheers
>>>> Anthon
>>>>
>>>>



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