Re: [PATCH v2] devargs: add blacklisting by linux interface name

["Charles (Chas) Williams" <3chas3@gmail.com>]

On Thu, 2015-11-05 at 11:23 -0800, Stephen Hemminger wrote:
> On Thu, 05 Nov 2015 11:39:04 -0500
> "Charles (Chas) Williams" <3chas3@gmail.com> wrote:
> 
> > On Wed, 2015-11-04 at 23:40 +0100, Thomas Monjalon wrote:
> > > 2015-10-14 09:41, Charles  Williams:  
> > > > On Tue, 2015-10-13 at 14:49 +0200, Olivier MATZ wrote:  
> > > > > For PCI devices that have several interfaces (I think it's the case for
> > > > > some Mellanox boards), maybe we should not store the interface name?  
> > > > 
> > > > I am not sure what you mean here.  If a device has multiple ethernet
> > > > interfaces, then it should a have seperate PCI device address space for
> > > > each interface (I dont know of any DPDK drivers that don't make this
> > > > assumption as well).  
> > > 
> > > mlx4 and cxgbe?  
> > 
> > OK, I see now.  I don't know of a way to tell if a device has multiple
> > ports just from the pci vendor/device id without maintaining some
> > sort of table.
> > 
> > Do these devices have multiple interfaces listed in their
> > /sys/devices/.../net diretory?  If so, matching one of the listed
> > interfaces can just blacklist the whole device similar to blacklisting
> > by the device id.
> 
> Devices with multiple ports are supposed to report the port via /sys/class/net/xxx/portid

But I want to find the ports associated by the PCI devices.


> But you aren't going to be able to blacklist only one port of these devices.
> The two drivers would be fighting over registers and IRQ management.
> Plus kernel bind/unbind is by PCI id.

I understand that.  Blacklisting an interface on a multiple port device
would be essentially the same as blacklist by the PCI device id.  You
can't split the PCI device.  I just need to find the list of ports
associated with a single PCI device.