[ovs-dev] Question about supporting the OVS out-of-tree kernel drivers

[Ilya Maximets]

On 11/12/20 6:04 PM, Gregory Rose wrote:
> 
> 
> On 11/12/2020 5:10 AM, Mark Gray wrote:
>> On 30/10/2020 18:32, Gregory Rose wrote:
>>>
>>> The question is whether there is any interest in continuing to support
>>> the OVS out-of-tree (OOT) kernel driver or should we deprecate it?  The
>>> latest kernel support for the OOT driver is up to 5.8.x  There seems to
>>> be little interest that I can tell in using the OOT driver.  The main
>>> distros all include the kernel built-in OVS driver and those drivers
>>> generally seem to support all the primary features required by user space.
>>>
>>> Most of the energy on this list seems to be directed toward DPDK and OVN
>>> and it doesn't seem to me that either of those require the OOT driver.
>>> If there's no one actually using the OOT driver I suggest we deprecate
>>> it and save time and energy on keeping it up to date.
>>>
>>> Opinions, thoughts, comments?
>>>
>>
>> I think it is good to raise this question. Thanks.
>>
>> It would certainly simplify development of kernel features and avoid the
>> type of issue that I had recently with a patch in the OOT tree but not
>> upstream. As I don't know who uses OOT, I can't comment beyond that.
> 
> I'm knee deep in some work at my day job but when I get a
> chance I'm going to send a patch for the faq, NEWS, etc. and request
> that we deprecate the OOT driver and end support for newer kernels
> at the current 5.8.  After that we'll only take bug fixes.
> 
> I don't really believe there are any consumers for the OOT driver
> on this list anymore.  Certainly the lack of response to this
> question indicates that.

CC: ovs-discuss

Thanks for raising this question.

As far as the topic goes, the only thing that might get people to use
the OOT module with kernels higher than 5.8 is SST or LISP support.
On the other hand, there were reasons to reject patches to support these
protocols in the mainline kernel.  And I have no idea if anyone is actually
using them.  I never used them and I'm not even sure if they actually work
taking into account that we have only 2 system tests for them that doesn't
really check much.

Maybe we could also raise the question during the conference to get more
attention.  I'd like to add a reference into my "community updates"
presentation.

I know that it takes a lot of time to support OOT kernel module and it
doesn't seem worth the effort.  I'd vote for deprecation and eventual
removal.  Sending patches is a good idea, with them we could move forward
if no strong objections will appear.  And thanks for all the work you did
supporting kernel module all that time!

Best regards, Ilya Maximets.