[PATCH net-next] net: hyperv: Add attributes to show RX/TX indirection table

[Chi Song <Song.Chi@microsoft.com>]

The network is observed with low performance, if TX indirection table is imbalance.
But the table is in memory and set in runtime, it's hard to know. Add them to attributes can help on troubleshooting.
---
 drivers/net/hyperv/netvsc_drv.c | 46 +++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 6267f706e8ee..cd6fe96e10c1 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2370,6 +2370,51 @@ static int netvsc_unregister_vf(struct net_device *vf_netdev)
 	return NOTIFY_OK;
 }
 
+static ssize_t tx_indirection_table_show(struct device *dev,
+					 struct device_attribute *dev_attr,
+					 char *buf)
+{
+	struct net_device *ndev = to_net_dev(dev);
+	struct net_device_context *ndc = netdev_priv(ndev);
+	int i = 0;
+	ssize_t offset = 0;
+
+	for (i = 0; i < VRSS_SEND_TAB_SIZE; i++)
+		offset += sprintf(buf + offset, "%u ", ndc->tx_table[i]);
+	buf[offset - 1] = '\n';
+
+	return offset;
+}
+static DEVICE_ATTR_RO(tx_indirection_table);
+
+static ssize_t rx_indirection_table_show(struct device *dev,
+					 struct device_attribute *dev_attr,
+					 char *buf)
+{
+	struct net_device *ndev = to_net_dev(dev);
+	struct net_device_context *ndc = netdev_priv(ndev);
+	int i = 0;
+	ssize_t offset = 0;
+
+	for (i = 0; i < ITAB_NUM; i++)
+		offset += sprintf(buf + offset, "%u ", ndc->rx_table[i]);
+	buf[offset - 1] = '\n';
+
+	return offset;
+}
+static DEVICE_ATTR_RO(rx_indirection_table);
+
+static struct attribute *netvsc_dev_attrs[] = {
+	&dev_attr_tx_indirection_table.attr,
+	&dev_attr_rx_indirection_table.attr,
+	NULL
+};
+
+const struct attribute_group netvsc_dev_group = {
+	.name = NULL,
+	.attrs = netvsc_dev_attrs,
+};
+
 static int netvsc_probe(struct hv_device *dev,
 			const struct hv_vmbus_device_id *dev_id)
 {
@@ -2410,6 +2455,7 @@ static int netvsc_probe(struct hv_device *dev,
 
 	net->netdev_ops = &device_ops;
 	net->ethtool_ops = &ethtool_ops;
+	net->sysfs_groups[0] = &netvsc_dev_group;
 	SET_NETDEV_DEV(net, &dev->device);
 
 	/* We always need headroom for rndis header */
-- 
2.25.1