[Qemu-devel] Windows2012R2 virtio-win drivers and IPv6

[Qemu-devel] Windows2012R2 virtio-win drivers and IPv6

[Peter Lieven]

Hi,

we observed problems with Windows Update Services and Uploading Files from a Windows System to other systems.
We tracked this down to IPv6 connections only. IPv4 and IPv6 in Receive direction seems to be not a problem.
It turned out that setting TCP/UDP Checksum Offloading for IPv6 from "RX/TX enabled" to RX "enabled" in the
Network Driver settings solved the issue. I remember similar problems existed with Linux some time ago.
Linux guests on the same host are also not an issue.

Is this a known issue? I tried latest and stable drivers from the Fedora Website.

Thanks,
Peter

Re: [Qemu-devel] Windows2012R2 virtio-win drivers and IPv6

[Vadim Rozenfeld]

On Thu, 2015-05-28 at 16:07 +0200, Peter Lieven wrote:
> Hi,
> 
> we observed problems with Windows Update Services and Uploading Files from a Windows System to other systems.
> We tracked this down to IPv6 connections only. IPv4 and IPv6 in Receive direction seems to be not a problem.
> It turned out that setting TCP/UDP Checksum Offloading for IPv6 from "RX/TX enabled" to RX "enabled" in the
> Network Driver settings solved the issue. I remember similar problems existed with Linux some time ago.
> Linux guests on the same host are also not an issue.
> 
> Is this a known issue? I tried latest and stable drivers from the Fedora Website.
> 

Adding Yan.

Best regards,
Vadim.
 
> Thanks,
> Peter
> 

Re: [Qemu-devel] Windows2012R2 virtio-win drivers and IPv6

[Peter Lieven]

Am 28.05.2015 um 16:24 schrieb Vadim Rozenfeld:
> On Thu, 2015-05-28 at 16:07 +0200, Peter Lieven wrote:
>> Hi,
>>
>> we observed problems with Windows Update Services and Uploading Files from a Windows System to other systems.
>> We tracked this down to IPv6 connections only. IPv4 and IPv6 in Receive direction seems to be not a problem.
>> It turned out that setting TCP/UDP Checksum Offloading for IPv6 from "RX/TX enabled" to RX "enabled" in the
>> Network Driver settings solved the issue. I remember similar problems existed with Linux some time ago.
>> Linux guests on the same host are also not an issue.
>>
>> Is this a known issue? I tried latest and stable drivers from the Fedora Website.
>>
> Adding Yan.

Hi Yan,

have you had a chance to look at this or a hint where to start?

Thanks,
Peter

Re: [Qemu-devel] Windows2012R2 virtio-win drivers and IPv6

[Yan Vugenfirer]

> On Jun 8, 2015, at 11:12 AM, Peter Lieven <pl@kamp.de> wrote:
> 
> Am 28.05.2015 um 16:24 schrieb Vadim Rozenfeld:
>> On Thu, 2015-05-28 at 16:07 +0200, Peter Lieven wrote:
>>> Hi,
>>> 
>>> we observed problems with Windows Update Services and Uploading Files from a Windows System to other systems.
>>> We tracked this down to IPv6 connections only. IPv4 and IPv6 in Receive direction seems to be not a problem.
>>> It turned out that setting TCP/UDP Checksum Offloading for IPv6 from "RX/TX enabled" to RX "enabled" in the
>>> Network Driver settings solved the issue. I remember similar problems existed with Linux some time ago.
>>> Linux guests on the same host are also not an issue.
>>> 
>>> Is this a known issue? I tried latest and stable drivers from the Fedora Website.
>>> 
>> Adding Yan.
> 
> Hi Yan,
> 
> have you had a chance to look at this or a hint where to start?
> 

Sorry Peter, somehow I missed the email and saw it only now.

* When you experience the issues is it between VMs on the same host? 

* Can you describe your host network configuration? 

* Can provide the output for "ethtool -k” for every NIC (including tap devices) in the host that is involved with the VM that has a problem?

 * What are the host kernel version, QEMU version and guest driver version you are using?

Thanks,
Yan.

> Thanks,
> Peter
> 
> 

Re: [Qemu-devel] Windows2012R2 virtio-win drivers and IPv6

[Peter Lieven]

Hi Yan,

thanks for the reply.

>
> * When you experience the issues is it between VMs on the same host?

I can reproduce it between a Windows VM on Host A and a Linux VM on Host B.
Linux and Windows are not on the same host systems due to licensing.

Between Linux VMs and/or if I download to the Windows VM there is no issue.
Only outbound TCP traffic from the Windows vServer is affected and it only affects IPv6 traffic.

>
> * Can you describe your host network configuration?

Windows VM on Qemu -> tap -> Linux Bridge -> eth (tagged) -> Network -> eth(tagged) -> Linux Bridge -> tap -> Linux VM on Qemu.

>
> * Can provide the output for "ethtool -k” for every NIC (including tap devices) in the host that is involved with the VM that has a problem?

Offload parameters for tap4:
rx-checksumming: off
tx-checksumming: on
scatter-gather: on
tcp-segmentation-offload: off
udp-fragmentation-offload: off
generic-segmentation-offload: on
generic-receive-offload: on
large-receive-offload: off
rx-vlan-offload: off
tx-vlan-offload: on
ntuple-filters: off
receive-hashing: off

Offload parameters for br136:
rx-checksumming: off
tx-checksumming: on
scatter-gather: on
tcp-segmentation-offload: off
udp-fragmentation-offload: off
generic-segmentation-offload: on
generic-receive-offload: on
large-receive-offload: off
rx-vlan-offload: off
tx-vlan-offload: on
ntuple-filters: off
receive-hashing: off

Offload parameters for eth2:
rx-checksumming: on
tx-checksumming: on
scatter-gather: on
tcp-segmentation-offload: on
udp-fragmentation-offload: off
generic-segmentation-offload: on
generic-receive-offload: off
large-receive-offload: off
rx-vlan-offload: on
tx-vlan-offload: on
ntuple-filters: off
receive-hashing: off



>
>   * What are the host kernel version, QEMU version and guest driver version you are using?

host: 3.13.0-53-generic
qemu: 2.2.1
guest dirver: 0.1.100

Thank You,
Peter