Re: [PATCH net-next 1/2] netdevsim: add link speed support

+static int nsim_get_link_ksettings(struct net_device *dev,
+				   struct ethtool_link_ksettings *cmd)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	cmd->base.speed		= ns->ethtool.speed;
+	cmd->base.duplex	= ns->ethtool.duplex;
+	cmd->base.port		= PORT_OTHER;
+	cmd->base.autoneg	= AUTONEG_DISABLE;

Here you hard code autoneg as disabled.

+static int nsim_set_link_ksettings(struct net_device *dev,
+				   const struct ethtool_link_ksettings *cmd)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+
+	if (cmd->base.speed > NSIM_LINK_SPEED_MAX)
+		return -EINVAL;
+
+	return ethtool_virtdev_set_link_ksettings(dev, cmd, &ns->ethtool.speed,
+						  &ns->ethtool.duplex);

but here you don't appear to block enabling autoneg. I would expect a
test and EOPNOTSUPP.

     Andrew