Re: [dpdk-dev] standardize device identification

[Thomas Monjalon <thomas@monjalon.net>]

Changing the title and adding more comments inline:

19/12/2017 00:05, Thomas Monjalon:
> 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)

The key/value pair describing the category scope is mandatory
and must be the first pair in the category properties.
Example: bus=pci, must be placed before id=0000:01:00.0

> 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?

Yuanhan is proposing to use this syntax in OVS option dpdk-devargs:
https://mail.openvswitch.org/pipermail/ovs-dev/2017-December/342273.html

Please, any feedback or approval that this syntax is good?