netdevsim: report stats by default, like a real device

Real devices should implement qstats. Devices which support
pause or FEC configuration should also report the relevant stats.

nsim was missing FEC stats completely, some of the qstats
and pause stats required toggling a debugfs knob.

Note that the tests which used pause always initialize the setting
so they shouldn't be affected by the different starting value.

Signed-off-by: Jakub Kicinski <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/netdevsim/ethtool.c

···
 	return 0;
 }
 
+static void
+nsim_get_fec_stats(struct net_device *dev, struct ethtool_fec_stats *fec_stats)
+{
+	fec_stats->corrected_blocks.total = 123;
+	fec_stats->uncorrectable_blocks.total = 4;
+}
+
 static int nsim_get_ts_info(struct net_device *dev,
 			    struct ethtool_ts_info *info)
 {
···
 	.set_channels			= nsim_set_channels,
 	.get_fecparam			= nsim_get_fecparam,
 	.set_fecparam			= nsim_set_fecparam,
+	.get_fec_stats			= nsim_get_fec_stats,
 	.get_ts_info			= nsim_get_ts_info,
 };
 
···
 	ns->netdev->ethtool_ops = &nsim_ethtool_ops;
 
 	nsim_ethtool_ring_init(ns);
+
+	ns->ethtool.pauseparam.report_stats_rx = true;
+	ns->ethtool.pauseparam.report_stats_tx = true;
 
 	ns->ethtool.fec.fec = ETHTOOL_FEC_NONE;
 	ns->ethtool.fec.active_fec = ETHTOOL_FEC_NONE;

drivers/net/netdevsim/netdev.c

···
 #include <linux/module.h>
 #include <linux/netdevice.h>
 #include <linux/slab.h>
+#include <net/netdev_queues.h>
 #include <net/netlink.h>
 #include <net/pkt_cls.h>
 #include <net/rtnetlink.h>
···
 	.ndo_set_features	= nsim_set_features,
 };
 
+/* We don't have true per-queue stats, yet, so do some random fakery here.
+ * Only report stuff for queue 0.
+ */
+static void nsim_get_queue_stats_rx(struct net_device *dev, int idx,
+				    struct netdev_queue_stats_rx *stats)
+{
+	struct rtnl_link_stats64 rtstats = {};
+
+	if (!idx)
+		nsim_get_stats64(dev, &rtstats);
+
+	stats->packets = rtstats.rx_packets - !!rtstats.rx_packets;
+	stats->bytes = rtstats.rx_bytes;
+}
+
+static void nsim_get_queue_stats_tx(struct net_device *dev, int idx,
+				    struct netdev_queue_stats_tx *stats)
+{
+	struct rtnl_link_stats64 rtstats = {};
+
+	if (!idx)
+		nsim_get_stats64(dev, &rtstats);
+
+	stats->packets = rtstats.tx_packets - !!rtstats.tx_packets;
+	stats->bytes = rtstats.tx_bytes;
+}
+
+static void nsim_get_base_stats(struct net_device *dev,
+				struct netdev_queue_stats_rx *rx,
+				struct netdev_queue_stats_tx *tx)
+{
+	struct rtnl_link_stats64 rtstats = {};
+
+	nsim_get_stats64(dev, &rtstats);
+
+	rx->packets = !!rtstats.rx_packets;
+	rx->bytes = 0;
+	tx->packets = !!rtstats.tx_packets;
+	tx->bytes = 0;
+}
+
+static const struct netdev_stat_ops nsim_stat_ops = {
+	.get_queue_stats_tx	= nsim_get_queue_stats_tx,
+	.get_queue_stats_rx	= nsim_get_queue_stats_rx,
+	.get_base_stats		= nsim_get_base_stats,
+};
+
 static void nsim_setup(struct net_device *dev)
 {
 	ether_setup(dev);
···
 
 	ns->phc = phc;
 	ns->netdev->netdev_ops = &nsim_netdev_ops;
+	ns->netdev->stat_ops = &nsim_stat_ops;
 
 	err = nsim_udp_tunnels_info_create(ns->nsim_dev, ns->netdev);
 	if (err)