Linux Virtualization - Jan 2016 - bonding (IEEE 802.3ad) not working with qemu/virtio

On 01/29/2016 10:45 PM, Jay Vosburgh wrote:
> Nikolay Aleksandrov <nikolay at cumulusnetworks.com> wrote:
> 
>> On 01/25/2016 05:24 PM, Bj?rnar Ness wrote:
>>> As subject says, 802.3ad bonding is not working with virtio network
model.
>>>
>>> The only errors I see is:
>>>
>>> No 802.3ad response from the link partner for any adapters in the
bond.
>>>
>>> Dumping the network traffic shows that no LACP packets are sent
from the
>>> host running with virtio driver, changing to for example e1000
solves
>>> this problem
>>> with no configuration changes.
>>>
>>> Is this a known problem?
>>>
>> [Including bonding maintainers for comments]
>>
>> Hi,
>> Here's a workaround patch for virtio_net devices that
"cheats" the
>> duplex test (which is the actual problem). I've tested this locally
>> and it works for me.
>> I'd let the others comment on the implementation, there're
other signs
>> that can be used to distinguish a virtio_net device so I'm open to
suggestions.
>> Also feedback if this is at all acceptable would be appreciated.
> 
> 	Should virtio instead provide an arbitrary speed and full duplex
> to ethtool, as veth does?
> 
> 	Creating a magic whitelist of devices deep inside the 802.3ad
> implementation seems less desirable.
> 
TBH, I absolutely agree. In fact here's what we've been doing:
add set_settings which allows the user to set any speed/duplex
and get_settings of course to retrieve that. This is also useful
for testing other stuff that requires speed and duplex, not only
for the bonding case.

I'll add the virtio_net maintainers to the discussion, see if it's
okay with everyone and I'll move to send patches once net-next opens up.

Thanks!

> 	-J
> 	
> ---
> 	-Jay Vosburgh, jay.vosburgh at canonical.com
>

From: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
Date: Fri, 29 Jan 2016 22:48:26 +0100
> On 01/29/2016 10:45 PM, Jay Vosburgh wrote:
>> Nikolay Aleksandrov <nikolay at cumulusnetworks.com> wrote:
>> 
>>> On 01/25/2016 05:24 PM, Bj?rnar Ness wrote:
>>>> As subject says, 802.3ad bonding is not working with virtio
network model.
>>>>
>>>> The only errors I see is:
>>>>
>>>> No 802.3ad response from the link partner for any adapters in
the bond.
>>>>
>>>> Dumping the network traffic shows that no LACP packets are sent
from the
>>>> host running with virtio driver, changing to for example e1000
solves
>>>> this problem
>>>> with no configuration changes.
>>>>
>>>> Is this a known problem?
>>>>
>>> [Including bonding maintainers for comments]
>>>
>>> Hi,
>>> Here's a workaround patch for virtio_net devices that
"cheats" the
>>> duplex test (which is the actual problem). I've tested this
locally
>>> and it works for me.
>>> I'd let the others comment on the implementation, there're
other signs
>>> that can be used to distinguish a virtio_net device so I'm open
to suggestions.
>>> Also feedback if this is at all acceptable would be appreciated.
>> 
>> 	Should virtio instead provide an arbitrary speed and full duplex
>> to ethtool, as veth does?
>> 
>> 	Creating a magic whitelist of devices deep inside the 802.3ad
>> implementation seems less desirable.
>> 
> TBH, I absolutely agree. In fact here's what we've been doing:
> add set_settings which allows the user to set any speed/duplex
> and get_settings of course to retrieve that. This is also useful
> for testing other stuff that requires speed and duplex, not only
> for the bonding case.
I also agree.  Having a whitelist is just rediculous.

There should be a default speed/duplex setting for such devices as well.
We can pick one that will be use universally for these kinds of devices.

Sat, Jan 30, 2016 at 07:59:24AM CET, davem at davemloft.net
wrote:
>From: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
>Date: Fri, 29 Jan 2016 22:48:26 +0100
>
>> On 01/29/2016 10:45 PM, Jay Vosburgh wrote:
>>> Nikolay Aleksandrov <nikolay at cumulusnetworks.com> wrote:
>>> 
>>>> On 01/25/2016 05:24 PM, Bj?rnar Ness wrote:
>>>>> As subject says, 802.3ad bonding is not working with virtio
network model.
>>>>>
>>>>> The only errors I see is:
>>>>>
>>>>> No 802.3ad response from the link partner for any adapters
in the bond.
>>>>>
>>>>> Dumping the network traffic shows that no LACP packets are
sent from the
>>>>> host running with virtio driver, changing to for example
e1000 solves
>>>>> this problem
>>>>> with no configuration changes.
>>>>>
>>>>> Is this a known problem?
>>>>>
>>>> [Including bonding maintainers for comments]
>>>>
>>>> Hi,
>>>> Here's a workaround patch for virtio_net devices that
"cheats" the
>>>> duplex test (which is the actual problem). I've tested this
locally
>>>> and it works for me.
>>>> I'd let the others comment on the implementation,
there're other signs
>>>> that can be used to distinguish a virtio_net device so I'm
open to suggestions.
>>>> Also feedback if this is at all acceptable would be
appreciated.
>>> 
>>> 	Should virtio instead provide an arbitrary speed and full duplex
>>> to ethtool, as veth does?
>>> 
>>> 	Creating a magic whitelist of devices deep inside the 802.3ad
>>> implementation seems less desirable.
>>> 
>> TBH, I absolutely agree. In fact here's what we've been doing:
>> add set_settings which allows the user to set any speed/duplex
>> and get_settings of course to retrieve that. This is also useful
>> for testing other stuff that requires speed and duplex, not only
>> for the bonding case.
>
>I also agree.  Having a whitelist is just rediculous.
>
>There should be a default speed/duplex setting for such devices as well.
>We can pick one that will be use universally for these kinds of devices.
Exposing made up speed for veth and virtio_net sounds odd to me. User
see 10000Mb/s but it makes no sense at all. It is just confusing.

I believe this is bonding bug and should be fixed in there. Team works
fine with virtio_net device and lacp runner.

On 01/30/2016 07:59 AM, David Miller wrote:
> From: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
> Date: Fri, 29 Jan 2016 22:48:26 +0100
> 
>> On 01/29/2016 10:45 PM, Jay Vosburgh wrote:
>>> Nikolay Aleksandrov <nikolay at cumulusnetworks.com> wrote:
>>>
>>>> On 01/25/2016 05:24 PM, Bj?rnar Ness wrote:
>>>>> As subject says, 802.3ad bonding is not working with virtio
network model.
>>>>>
>>>>> The only errors I see is:
>>>>>
>>>>> No 802.3ad response from the link partner for any adapters
in the bond.
>>>>>
>>>>> Dumping the network traffic shows that no LACP packets are
sent from the
>>>>> host running with virtio driver, changing to for example
e1000 solves
>>>>> this problem
>>>>> with no configuration changes.
>>>>>
>>>>> Is this a known problem?
>>>>>
>>>> [Including bonding maintainers for comments]
>>>>
>>>> Hi,
>>>> Here's a workaround patch for virtio_net devices that
"cheats" the
>>>> duplex test (which is the actual problem). I've tested this
locally
>>>> and it works for me.
>>>> I'd let the others comment on the implementation,
there're other signs
>>>> that can be used to distinguish a virtio_net device so I'm
open to suggestions.
>>>> Also feedback if this is at all acceptable would be
appreciated.
>>>
>>> 	Should virtio instead provide an arbitrary speed and full duplex
>>> to ethtool, as veth does?
>>>
>>> 	Creating a magic whitelist of devices deep inside the 802.3ad
>>> implementation seems less desirable.
>>>
>> TBH, I absolutely agree. In fact here's what we've been doing:
>> add set_settings which allows the user to set any speed/duplex
>> and get_settings of course to retrieve that. This is also useful
>> for testing other stuff that requires speed and duplex, not only
>> for the bonding case.
> 
> I also agree.  Having a whitelist is just rediculous.
> 
> There should be a default speed/duplex setting for such devices as well.
> We can pick one that will be use universally for these kinds of devices.
> 
Yes, that's the other thing - the default setting, from a brief grepping
I see that veth uses 10Gbps, tun uses 10Mbps and batman-adv uses 10Mbps.

If we add a default get_settings that can be used by virtual devices
in ethtool that returns 10Gbps with the settings set like veth does
sounds good to me. What do you think ?

In fact they all set the same settings (apart from speed) so we can
consolidate them in a single default setting init function and for the
ones using different speed do something like:
__ethtool_init_settings(); <- sets everything like veth would with 10Mbps
speed
__ethtool_cmd_speed_set(cmd, SPEED_10000);
And we're done.

On Fri, Jan 29, 2016 at 10:48:26PM +0100, Nikolay Aleksandrov
wrote:
> On 01/29/2016 10:45 PM, Jay Vosburgh wrote:
> > Nikolay Aleksandrov <nikolay at cumulusnetworks.com> wrote:
> > 
> >> On 01/25/2016 05:24 PM, Bj?rnar Ness wrote:
> >>> As subject says, 802.3ad bonding is not working with virtio
network model.
> >>>
> >>> The only errors I see is:
> >>>
> >>> No 802.3ad response from the link partner for any adapters in
the bond.
> >>>
> >>> Dumping the network traffic shows that no LACP packets are
sent from the
> >>> host running with virtio driver, changing to for example e1000
solves
> >>> this problem
> >>> with no configuration changes.
> >>>
> >>> Is this a known problem?
> >>>
> >> [Including bonding maintainers for comments]
> >>
> >> Hi,
> >> Here's a workaround patch for virtio_net devices that
"cheats" the
> >> duplex test (which is the actual problem). I've tested this
locally
> >> and it works for me.
> >> I'd let the others comment on the implementation, there're
other signs
> >> that can be used to distinguish a virtio_net device so I'm
open to suggestions.
> >> Also feedback if this is at all acceptable would be appreciated.
> > 
> > 	Should virtio instead provide an arbitrary speed and full duplex
> > to ethtool, as veth does?
> > 
> > 	Creating a magic whitelist of devices deep inside the 802.3ad
> > implementation seems less desirable.
> > 
> TBH, I absolutely agree. In fact here's what we've been doing:
> add set_settings which allows the user to set any speed/duplex
> and get_settings of course to retrieve that. This is also useful
> for testing other stuff that requires speed and duplex, not only
> for the bonding case.
This looks like a very reasonable thing to do:
user might have knowledge of the actual speed through
some side-channel.

We might also propagate it to hypervisor in the future.

And this sound useful even if bonding is changed
to allow DUPLEX_UNKNOWN.

So please post this patch.

> I'll add the virtio_net maintainers to the discussion, see if it's
> okay with everyone and I'll move to send patches once net-next opens
up.
> 
> Thanks!
> 
> 
> > 	-J
> > 	
> > ---
> > 	-Jay Vosburgh, jay.vosburgh at canonical.com
> >

On 01/29/2016 10:59 PM, David Miller wrote:
> There should be a default speed/duplex setting for such devices as well.
> We can pick one that will be use universally for these kinds of devices.
There is at least one monitoring tool - collectl - which gets a trifle 
upset when the actual speed through an interface is significantly 
greater than the reported link speed.  I have to wonder how unique it is 
in that regard.

Doesn't mean there can't be a default, but does suggest it should be 
rather high.

rick jones