Re: [PATCH RFC 0/2] ethtool: Add actual port speed reporting

[Gal Pressman <galp.dev@gmail.com>]

On 02/11/2016 17:50, Mintz, Yuval wrote:
>> Sending RFC to get feedback for the following ethtool proposal:
>>
>> In some cases such as virtual machines and multi functions (SR-IOV), the actual
>> bandwidth exposed for each machine is not accurately shown in ethtool.
>> Currently ethtool shows only physical port link speed.
>> In our case we would like to show the virtual port operational link speed which
>> in some cases is less than the physical port speed.
>>
>> This will give users better visibility for the actual speed running on their device.
>>
>> $ ethtool ens6
>> ...
>> Speed: 50000Mb/s
>> Actual speed: 25000Mb/s
> 
> Not saying this is a bad thing, but where exactly is it listed that ethtool has
> to show the physical port speed?
> E.g., bnx2x shows the logical speed instead, and has been doing that for years.
> [Perhaps that's a past wrongness, but that's how it goes].
> 
> And besides, one can argue that in the SR-IOV scenario the VF has no business
> knowing the physical port speed.
> 

Good point, but there are more use-cases we should consider.
For example, when using Multi-Host/Flex-10/Multi-PF each PF should
be able to query both physical port speed and actual speed.