Re: [patch net-next RFC 00/10] introduce line card support for modular switch

[Ido Schimmel <idosch@idosch.org>]

On Wed, Jan 13, 2021 at 01:12:12PM +0100, Jiri Pirko wrote:
> # Create a new netdevsim device, with no ports and 2 line cards:
> $ echo "10 0 2" >/sys/bus/netdevsim/new_device
> $ devlink port # No ports are listed
> $ devlink lc
> netdevsim/netdevsim10:
>   lc 0 state unprovisioned
>     supported_types:
>        card1port card2ports card4ports
>   lc 1 state unprovisioned
>     supported_types:
>        card1port card2ports card4ports
> 
> # Note that driver advertizes supported line card types. In case of
> # netdevsim, these are 3.
> 
> $ devlink lc provision netdevsim/netdevsim10 lc 0 type card4ports

Why do we need a separate command for that? You actually introduced
'DEVLINK_CMD_LINECARD_SET' in patch #1, but it's never used.

I prefer:

devlink lc set netdevsim/netdevsim10 index 0 state provision type card4ports
devlink lc set netdevsim/netdevsim10 index 0 state unprovision

It is consistent with the GET/SET/NEW/DEL pattern used by other
commands.

> $ devlink lc
> netdevsim/netdevsim10:
>   lc 0 state provisioned type card4ports
>     supported_types:
>        card1port card2ports card4ports
>   lc 1 state unprovisioned
>     supported_types:
>        card1port card2ports card4ports
> $ devlink port
> netdevsim/netdevsim10/1000: type eth netdev eni10nl0p1 flavour physical lc 0 port 1 splittable false
> netdevsim/netdevsim10/1001: type eth netdev eni10nl0p2 flavour physical lc 0 port 2 splittable false
> netdevsim/netdevsim10/1002: type eth netdev eni10nl0p3 flavour physical lc 0 port 3 splittable false
> netdevsim/netdevsim10/1003: type eth netdev eni10nl0p4 flavour physical lc 0 port 4 splittable false
> #                                                 ^^                    ^^^^
> #                                     netdev name adjusted          index of a line card this port belongs to
> 
> $ ip link set eni10nl0p1 up 
> $ ip link show eni10nl0p1   
> 165: eni10nl0p1: <NO-CARRIER,BROADCAST,NOARP,UP> mtu 1500 qdisc noqueue state DOWN mode DEFAULT group default qlen 1000
>     link/ether 7e:2d:05:93:d3:d1 brd ff:ff:ff:ff:ff:ff
> 
> # Now activate the line card using debugfs. That emulates plug-in event
> # on real hardware:
> $ echo "Y"> /sys/kernel/debug/netdevsim/netdevsim10/linecards/0/active
> $ ip link show eni10nl0p1
> 165: eni10nl0p1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
>     link/ether 7e:2d:05:93:d3:d1 brd ff:ff:ff:ff:ff:ff
> # The carrier is UP now.
> 
> Jiri Pirko (10):
>   devlink: add support to create line card and expose to user
>   devlink: implement line card provisioning
>   devlink: implement line card active state
>   devlink: append split port number to the port name
>   devlink: add port to line card relationship set
>   netdevsim: introduce line card support
>   netdevsim: allow port objects to be linked with line cards
>   netdevsim: create devlink line card object and implement provisioning
>   netdevsim: implement line card activation
>   selftests: add netdevsim devlink lc test
> 
>  drivers/net/netdevsim/bus.c                   |  21 +-
>  drivers/net/netdevsim/dev.c                   | 370 ++++++++++++++-
>  drivers/net/netdevsim/netdev.c                |   2 +
>  drivers/net/netdevsim/netdevsim.h             |  23 +
>  include/net/devlink.h                         |  44 ++
>  include/uapi/linux/devlink.h                  |  25 +
>  net/core/devlink.c                            | 443 +++++++++++++++++-
>  .../drivers/net/netdevsim/devlink.sh          |  62 ++-
>  8 files changed, 964 insertions(+), 26 deletions(-)
> 
> -- 
> 2.26.2
>