Re: [dpdk-dev] [PATCH] [RFC] ether: standardize getting the port by name

[Thomas Monjalon <thomas@monjalon.net>]

Let's summarize and resume this thread.

We need a generic syntax to describe a device.
This syntax can be used
	- before initializing the device (i.e. whitelist/blacklist)
	- or after the initialization (e.g. user config)

We need to answer 4 questions:
1/ what are the separators (comma, colon, etc)?
2/ how to distinguish a device identification from a configuration?
3/ what are the mandatory parts?
4/ what can be the optional properties?

30/11/2017 08:35, Yuanhan Liu:
> What this patch proposes is to use "name[,mac]" syntax. "name" is the
> PCI id for pci device. For vdev, it's the vdev name given by user. The
> reason "mac" is needed is for some devices (say ConnectX-3), 2 ports
> (in a single NIC) have the same PCI id.

Based on the feedbacks we had, I suggest a syntax where everything is
optional key/value pairs, and split in 3 categories:
	- bus (pci, vdev, vmbus, fslmc, etc)
	- class (eth, crypto)
	- driver (i40e, mlx5, virtio, etc)

Between categories, the separator is a slash.
Inside a category, the separator is a comma.
Inside a key/value pair, the separator is an equal sign.

It may look like this:
bus=BUS_NAME,id=BUS_ID/class=CLASS_NAME,dev_port=PORT_NUM,mac=MAC_ADDRESS/driver=DRIVER_NAME,driverspecificproperty=VALUE

A device is identified when every properties are matched.
Before device is probed, only the bus category is relevant.
For the simple PCI whitelist, it means moving from
	-w 0000:01:00.0
to
	-w bus=pci,id=0000:01:00.0

It is possible to mix some settings in these devargs syntax if the keys
are differents. Example: mac= is for identification by MAC, whereas
newmac= would be for specifying a MAC address to set.

Agreement?