[dpdk-dev] [PATCH] doc: announce KNI ethtool removal

Ferruh Yigit ferruh.yigit at intel.com
Tue Jul 26 15:18:04 CEST 2016


On 7/22/2016 6:20 PM, Andriy Berestovskyy wrote:
> Hi folks,
> Just to clarify. Thomas is talking about removing just the KNI ethtool
> (i.e. lib/librte_eal/linuxapp/kni/ethtool/*). The major functionality
> of those 45K lines of code is to get the same MAC address on the KNI
> interface and the underlying igb/ixgbe NIC.

Yes what we talk here is "KNI ethtool" but its major functionality is
NOT getting MAC address from device. Basically it lets issuing ethtool
commands to the device via virtual interface.
Like for a device that controlled by DPDK, it is possible to read device
registers, or read/write eeprom of the device via this feature.
So as name suggests, it enables ethtool support for device.

> 
> At the moment the rest of the DPDK eth devices work fine without the
> KNI ethtool. 

Of course, this is an optional feature, drivers doesn't support this
feature will work fine.
So keeping this feature, doesn't cost any to drivers that doesn't
support this feature.

> The workaround is very simple: use ifconfig or ip tool to
> set the same MAC you have on your NIC. Put it into your network
> configuration to make it permanent.
> 
> Examples:
> ifconfig vEth0_0 hw ether <your NIC's MAC>
> or
> ip link set vEth0_0 address <your NIC's MAC>
> or
> in /etc/network/interfaces under the "iface vEth0_0" section add the following:
>     hwaddress <your NIC's MAC>
> 
> 
> Andriy
> 
> On Thu, Jul 21, 2016 at 10:54 PM, Jay Rolette <rolette at infinite.io> wrote:
>> On Thu, Jul 21, 2016 at 3:32 PM, Thomas Monjalon <thomas.monjalon at 6wind.com>
>> wrote:
>>
>>> 2016-07-21 13:20, Jay Rolette:
>>>> On Thu, Jul 21, 2016 at 10:33 AM, Ferruh Yigit <ferruh.yigit at intel.com>
>>>> wrote:
>>>>> KNI ethtool is functional and maintained, and it may have users!
>>>>>
>>>>> Why just removing it, specially without providing an alternative?
>>>>> Is is good time to discuss KCP again?
>>>>
>>>> Yes, my product uses it.
>>>
>>> Your product uses what? KCP? KNI? KNI ethtool?
>>>
>>
>> Sorry, that wasn't very clear. It uses KNI + ifconfig to configure the
>> device/interface in Linux. I'm assuming the "ethtool" bits under discussion
>> are the same things that make ifconfig work with KNI to the limited extent
>> it does.
>>
>>> Seems like we are back to the same discussion we
>>>> had a few months ago about the KNI situation...
>>>>
>>>> It shouldn't be removed unless there is a replacement, ideally one that
>>>> works with the normal Linux tools like every other network device.
>>>
>>> This ethtool module works only for igb and ixgbe!
>>> There is already no replacement for other drivers.
>>> Who works on a replacement?
>>>
>>
>> Ferruh submitted KCP previously, but you guys didn't like the fact that it
>> was a kernel module. IIRC, one of the gains from that was simplified
>> maintenance because you didn't need driver specific support for KNI.
>> Assuming he's still willing to beat it into shape, we have something that
>> is already most of the way there.
>>
>> If people are going to continue to block it because it is a kernel module,
>> then IMO, it's better to leave the existing support on igx / ixgbe in place
>> instead of stepping backwards to zero support for ethtool.
>>
>>> While the code wasn't ready at the time, it was a definite improvement
>>> over what
>>>> we have with KNI today.
>>>
> 
> 
> 



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