Re: [PATCH 0/2] Drivers: hv: vmbus: Miscellaneous improvements

[Andrea Parri]

On Mon, Oct 07, 2019 at 05:41:10PM +0000, Dexuan Cui wrote:
> > From: linux-hyperv-owner@xxxxxxxxxxxxxxx
> > <linux-hyperv-owner@xxxxxxxxxxxxxxx> On Behalf Of Andrea Parri
> > Sent: Monday, October 7, 2019 9:31 AM
> > 
> > Hi all,
> > 
> > The patchset:
> > 
> > - simplifies/refactors the VMBus negotiation code by introducing
> >   the table of VMBus protocol versions (patch 1/2),
> > 
> > - enables VMBus protocol versions 5.1 and 5.2 (patch 2/2).
> > 
> > Thanks,
> >   Andrea
> > 
> > Andrea Parri (2):
> >   Drivers: hv: vmbus: Introduce table of VMBus protocol versions
> >   Drivers: hv: vmbus: Enable VMBus protocol versions 5.1 and 5.2
> 
> Should we add a module parameter to allow the user to specify a lower
> protocol version, when the VM runs on the latest host? 
> 
> This can be useful for testing and debugging purpose: the variable
> "vmbus_proto_version" is referenced by the vmbus driver itself and
> some VSC drivers: if we always use the latest available proto version,
> some code paths can not be tested on the latest hosts. 

The idea is appealing to me (altough I made no attempt to implement/test
it yet).  What do others think about this?  Maybe can be considered as a
follow-up patch/work to this series?

Thanks,
  Andrea