RE: [PATCH v5 07/12] net/nfp: add flower ctrl VNIC related logics

[Chaoyong He <chaoyong.he@corigine.com>]

> On Mon, 8 Aug 2022 11:32:30 +0000
> Chaoyong He <chaoyong.he@corigine.com> wrote:
> 
> > > > +		goto done;
> > > > +
> > > > +	/* Allocate memory for the eth_dev of the vNIC */
> > > > +	hw->eth_dev = rte_zmalloc("ctrl_vnic_eth_dev",
> > >
> > > Why not rte_eth_dev_allocate()? Isn't an ethdev?
> > > Why do you bypsss ethdev layer in this case completely and do
> > > everything yourself?
> >
> > Here we created an ethdev locally to nfp PMD, we want the user totally
> won't be aware of it.
> > If we use rte_eth_dev_allocate() to create it, it will be in array
> 'rte_ethdev_devices[]', that's not we want.
> 
> Having a floating ethdev does open the code and users up to a number of
> potential bugs.
> What is the value of port_id on that ethdev? What is the mechanism to
> ensure it doesn't conflict with other ones in the system.

The 'port_id' is the 'Device [external] port identifier', which related with the
'rte_ethdev_devices[]' I think.
Here the ethdev we created is not exposed to the user and is not in the 'rte_ethdev_devices[]'
array, so it can't be invoked by the user at all.
And we invoke this ethdev through a pointer in the `struct nfp_net_hw`,
so I think there should no conflict with other ones in the system.