Merge branch 'virtio_net_ethtool_settings'

Nikolay Aleksandrov says:

====================
virtio_net: add ethtool get/set settings support

Patch 1 adds ethtool speed/duplex validation functions which check if the
value is defined. Patch 2 adds support for ethtool (get|set)_settings and
uses the validation functions to check the user-supplied values.

v2: split in 2 patches to allow everyone to make use of the validation
functions and allow virtio_net devices to be half duplex
v3: added a check to return error if the user tries to change anything else
besides duplex/speed as per Michael's comment
v4: Set port type to PORT_OTHER
v5: clear diff1.port (ignore port) when checking for changes since we set
it now and ethtool uses it in the set request

Sorry about the pointless iterations, should've all covered now.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/virtio_net.c

@@ -146,6 +146,10 @@ struct virtnet_info {
 	virtio_net_ctrl_ack ctrl_status;
 	u8 ctrl_promisc;
 	u8 ctrl_allmulti;
+
+	/* Ethtool settings */
+	u8 duplex;
+	u32 speed;
 };
 
 struct padded_vnet_hdr {
@@ -1376,6 +1380,58 @@ static void virtnet_get_channels(struct net_device *dev,
 	channels->other_count = 0;
 }
 
+/* Check if the user is trying to change anything besides speed/duplex */
+static bool virtnet_validate_ethtool_cmd(const struct ethtool_cmd *cmd)
+{
+	struct ethtool_cmd diff1 = *cmd;
+	struct ethtool_cmd diff2 = {};
+
+	/* advertising and cmd are usually set, ignore port because we set it */
+	ethtool_cmd_speed_set(&diff1, 0);
+	diff1.advertising = 0;
+	diff1.duplex = 0;
+	diff1.port = 0;
+	diff1.cmd = 0;
+
+	return !memcmp(&diff1, &diff2, sizeof(diff1));
+}
+
+static int virtnet_set_settings(struct net_device *dev, struct ethtool_cmd *cmd)
+{
+	struct virtnet_info *vi = netdev_priv(dev);
+	u32 speed;
+
+	speed = ethtool_cmd_speed(cmd);
+	/* don't allow custom speed and duplex */
+	if (!ethtool_validate_speed(speed) ||
+	    !ethtool_validate_duplex(cmd->duplex) ||
+	    !virtnet_validate_ethtool_cmd(cmd))
+		return -EINVAL;
+	vi->speed = speed;
+	vi->duplex = cmd->duplex;
+
+	return 0;
+}
+
+static int virtnet_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
+{
+	struct virtnet_info *vi = netdev_priv(dev);
+
+	ethtool_cmd_speed_set(cmd, vi->speed);
+	cmd->duplex = vi->duplex;
+	cmd->port = PORT_OTHER;
+
+	return 0;
+}
+
+static void virtnet_init_settings(struct net_device *dev)
+{
+	struct virtnet_info *vi = netdev_priv(dev);
+
+	vi->speed = SPEED_UNKNOWN;
+	vi->duplex = DUPLEX_UNKNOWN;
+}
+
 static const struct ethtool_ops virtnet_ethtool_ops = {
 	.get_drvinfo = virtnet_get_drvinfo,
 	.get_link = ethtool_op_get_link,
@@ -1383,6 +1439,8 @@ static const struct ethtool_ops virtnet_ethtool_ops = {
 	.set_channels = virtnet_set_channels,
 	.get_channels = virtnet_get_channels,
 	.get_ts_info = ethtool_op_get_ts_info,
+	.get_settings = virtnet_get_settings,
+	.set_settings = virtnet_set_settings,
 };
 
 #define MIN_MTU 68
@@ -1855,6 +1913,8 @@ static int virtnet_probe(struct virtio_device *vdev)
 	netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs);
 	netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs);
 
+	virtnet_init_settings(dev);
+
 	err = register_netdev(dev);
 	if (err) {
 		pr_debug("virtio_net: registering device failed\n");

include/uapi/linux/ethtool.h

@@ -1319,11 +1319,45 @@ enum ethtool_sfeatures_retval_bits {
 
 #define SPEED_UNKNOWN		-1
 
+static inline int ethtool_validate_speed(__u32 speed)
+{
+	switch (speed) {
+	case SPEED_10:
+	case SPEED_100:
+	case SPEED_1000:
+	case SPEED_2500:
+	case SPEED_5000:
+	case SPEED_10000:
+	case SPEED_20000:
+	case SPEED_25000:
+	case SPEED_40000:
+	case SPEED_50000:
+	case SPEED_56000:
+	case SPEED_100000:
+	case SPEED_UNKNOWN:
+		return 1;
+	}
+
+	return 0;
+}
+
 /* Duplex, half or full. */
 #define DUPLEX_HALF		0x00
 #define DUPLEX_FULL		0x01
 #define DUPLEX_UNKNOWN		0xff
 
+static inline int ethtool_validate_duplex(__u8 duplex)
+{
+	switch (duplex) {
+	case DUPLEX_HALF:
+	case DUPLEX_FULL:
+	case DUPLEX_UNKNOWN:
+		return 1;
+	}
+
+	return 0;
+}
+
 /* Which connector port. */
 #define PORT_TP			0x00
 #define PORT_AUI		0x01