Wed, Mar 28, 2018 at 03:22:00AM CEST, dsa@cumulusnetworks.com wrote:

Add devlink support to netdevsim and use it to implement a simple,
profile based resource controller. Only one controller is needed
per namespace, so the first netdevsim netdevice in a namespace
registers with devlink. If that device is deleted, the resource
settings are deleted.

I don't understand why you add 1:1 fixed relationship between
netnamespace and devlink instance. That is highly misleading and reader
might think that those 2 are somehow related. They are not. You can have
multiple devlink instances for many ports in a single namespace.

Could you please clarify?

Also, to see the relationship between individual netdevsim netdevices
and the parent devlink instance, we should use devlink_port
instances, like this: 

      devlink1              devlink2
       |    |                |    |
 dl_port1_1 dlport1_2   dlport2_1 dlport2_2
       |    |                |    |
     eth0  eth1             eth2 eth3

Note that "devlink instance" reprensents one ASIC.
The address of the devlink instance is the bus address of the ASIC.
Here, you use address of some/first netdevsim netdev instance.

The way it is implemented in netdevsim by this patch is wrong on
so many levels :(

Could you please fix this? I'm more than happy to help you with this,
please say so. Thanks!


[...]

+	err = devlink_resource_register(devlink, "IPv4", (u64)-1,
+					NSIM_RESOURCE_IPV4,
+					DEVLINK_RESOURCE_ID_PARENT_TOP,
+					&params, NULL);
+	if (err) {
+		pr_err("Failed to register IPv4 top resource\n");
+		goto out;

this goto is pointless. Just return.