Re: [dpdk-dev] [PATCH 2/2] hyperv: VMBUS support infrastucture

[Thomas Monjalon <thomas.monjalon@6wind.com>]

2016-12-16 12:15, Stephen Hemminger:
> On Fri, 16 Dec 2016 19:09:02 +0100
> Thomas Monjalon <thomas.monjalon@6wind.com> wrote:
> 
> > 2016-12-15 09:26, Stephen Hemminger:
> > > On Thu, 15 Dec 2016 12:19:44 +0530
> > > Shreyansh Jain <shreyansh.jain@nxp.com> wrote:  
> > > > It is not a scale-able model where we have to change eth_driver/eth_dev 
> > > > for every new device type, other than PCI. Maybe VMBus is _very_ close 
> > > > to PCI so no changes are required in PCI layer (common, linuxapp, 
> > > > bsdapp) - but, for others it won't stop there.
> > > > 
> > > > At the least, rte_pci_driver/rte_pci_device should be removed from 
> > > > eth_driver & rte_eth_dev, respectively - relying on rte_driver and 
> > > > rte_device.
> > > > 
> > > > This is the primary reason work on the SoC patchset and now the new Bus 
> > > > model is being done.  
> > > 
> > > Agreed. the better long term model is to use C style inheritance where
> > > rte_pci_driver has eth_driver inside. 
> > > The other alternative is to make the second element an opaque pointer.
> > > 
> > > But that was too big a change, and not necessary to get VMBUS to work.
> > > Longer term refactoring will take more effort. Go ahead and address it
> > > with a better bus model, but that probably isn't going to be ready for
> > > a couple of releases.  
> > 
> > We'll consider only the approach of generalizing the bus model for integr	ation.
> > Stephen, you are welcome to help make it happen and rebase your work
> > on top of this new model.
> > Thanks
> 
> I will generalize it to PCI and VMBUS only. I am not inventing a generic SOC
> model since that is something that I don't have sufficient knowledge. This
> fits the YAGNI principle. 

There is already a work in progress to generalize bus handling. It is not
specific to SoC design. It is just a better design to add new buses.