[ovs-discuss] For help about ssh between vms through ovs-dkdp

[Daniele Di Proietto]

On 20/05/2015 15:21, "Traynor, Kevin" <kevin.traynor at intel.com> wrote:

>
>
>> -----Original Message-----
>
>> From: Daniele Di Proietto [mailto:diproiettod at vmware.com]
>
>> Sent: Wednesday, May 20, 2015 1:47 PM
>
>> To: 钢锁0310
>
>> Cc: 通天晓0280; discuss; Traynor, Kevin
>
>> Subject: Re: [ovs-discuss] For help about ssh between vms through
>>ovs-dkdp
>
>> 
>
>> This might be related to offloading features.
>
>> 
>
>> Could you try again with this qemu "-device" option and let us know?
>
>> -device
>
>> 
>>virtio-net-pci,netdev=net1,csum=off,gso=off,guest_tso4=off,guest_tso6=off
>>,g
>
>> uest_ecn=off
>
>
>
>I checked this previously and the DPDK vhost lib will report those
>features
>
>as not available during negotiation so you should be ok with not
>specifying
>
>them explicitly in the qemu cmd line. I haven't tested with qemu 2.3.
>
>
>
>> 
>
>> 
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>> Kevin, do you this we should mention this in INSTALL.DPDk.md?
>
>
>
>I had changed the original patch to make it optional in 3a based on
>feedback
>
>from Michael Tsirkin and testing. So unless we find an issue, I'd prefer
>to
>
>leave optional. 
>
>https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_openvswitc
>h_ovs_blob_master_INSTALL.DPDK.md-23dpdk-2Dvhost-2Dvm-2Dconfiguration&d=Aw
>IGoQ&c=Sqcl0Ez6M0X8aeM67LKIiDJAXVeAw-YihVMNtXt-uEs&r=SmB5nZacmXNq0gKCC1s_C
>w5yUNjxgD4v5kJqZ2uWLlE&m=iM-aCjDqF2zfP98Zeafj9Z78WnCYvkzPSyZeV1kVGWg&s=SOm
>_egKoAfzUwWioueTrQ9W2sa_WSUwKC74LO5SNvWs&e=
>

If I don't add the extra options, my guests (Debian wheezy kernel 3.2 and
Ubuntu 14.04 kernel 3.13, running on QEMU 2.1.3) see these features

# ethtool -k eth0

Features for eth0:
                                                rx-checksumming: off
[fixed]
                                                tx-checksumming: on
        tx-checksum-ipv4: off [fixed]
        tx-checksum-unneeded: off [fixed]
        tx-checksum-ip-generic: on
        tx-checksum-ipv6: off [fixed]
        tx-checksum-fcoe-crc: off [fixed]
        tx-checksum-sctp: off [fixed]
                                                scatter-gather: on
        tx-scatter-gather: on
        tx-scatter-gather-fraglist: on
                                                tcp-segmentation-offload:
on
        tx-tcp-segmentation: on
        tx-tcp-ecn-segmentation: on
        tx-tcp6-segmentation: on
                                                udp-fragmentation-offload:
on
                   
generic-segmentation-offload: on
                                                generic-receive-offload: on
                                                large-receive-offload: off
[fixed]
[...]


Pings work, but everything else (e.g. DNS lookups) doesn't.
To fix the setup I have either to add the extra options or to disable the
offloads (inside the guest) with

  ethtool -K eth0 tx off