Re: [PATCH 02/15] hyperv: Add a function to detect hv_device

[Greg KH]

On Fri, Dec 02, 2016 at 03:38:51PM +0000, KY Srinivasan wrote:
> 
> 
> > -----Original Message-----
> > From: Greg KH [mailto:gregkh@xxxxxxxxxxxxxxxxxxx]
> > Sent: Thursday, December 1, 2016 11:36 PM
> > To: KY Srinivasan <kys@xxxxxxxxxxxxx>
> > Cc: linux-kernel@xxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx;
> > olaf@xxxxxxxxx; apw@xxxxxxxxxxxxx; vkuznets@xxxxxxxxxx;
> > jasowang@xxxxxxxxxx; leann.ogasawara@xxxxxxxxxxxxx; Haiyang Zhang
> > <haiyangz@xxxxxxxxxxxxx>
> > Subject: Re: [PATCH 02/15] hyperv: Add a function to detect hv_device
> > 
> > On Fri, Dec 02, 2016 at 07:14:03AM +0000, KY Srinivasan wrote:
> > > > In other words, why do you need this and PCI or USB doesn't?  Why is
> > > > hyperv "special"?
> > >
> > > On Hyper-V, each VF interface (SR-IOV interface)
> > > is paired with an instance of the
> > > synthetic interface that is managed by netvsc.
> > > When the VF interface comes up, we
> > > need to associate the VF instance with
> > > the corresponding netvsc instance. To do this
> > > without modifying the VF drivers, netvsc registers
> > > for netdev events.
> > 
> > Why not modify the VF drivers?  You have the full source to them...
> Greg,
> 
> This is even worse. On Linux, VF drivers are hypervisor agnostic
> and I want to keep it that way.

Ok, I really don't know what to suggest, other than this is probably not
the way to do this as no other bus has to.  As I don't see the code that
actually uses this anywhere, it's really impossible to have this
conversation at all :(

greg k-h