Linux Virtualization - Feb 2016 - [PATCH net-next] virtio_net: add ethtool support for set and get of settings

From: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>

This patch allows the user to set and retrieve speed and duplex of the
virtio_net device via ethtool. Having this functionality is very helpful
for simulating different environments and also enables the virtio_net
device to participate in operations where proper speed and duplex are
required (e.g. currently bonding lacp mode requires full duplex). Custom
speed and duplex are not allowed, the user-supplied settings are validated
before applying. Only full and unknown duplex are allowed to be set.

Example:
$ ethtool eth1
Settings for eth1:
...
	Speed: Unknown!
	Duplex: Unknown! (255)
$ ethtool -s eth1 speed 1000 duplex full
$ ethtool eth1
Settings for eth1:
...
	Speed: 1000Mb/s
	Duplex: Full

Based on a patch by Roopa Prabhu.

CC: Roopa Prabhu <roopa at cumulusnetworks.com>
CC: Michael S. Tsirkin <mst at redhat.com>
CC: virtualization at lists.linux-foundation.org
Signed-off-by: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
---
Allowed to set unknown speed/duplex if the user wants to reset them, though
the user-space ethtool tool currently doesn't allow setting them.

 drivers/net/virtio_net.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 767ab11a6e9f..722ade567ee5 100644
--- a/drivers/net/virtio_net.c
+++ b/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 +1380,72 @@ static void virtnet_get_channels(struct net_device *dev,
 	channels->other_count = 0;
 }
 
+static bool virtnet_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 true;
+	}
+
+	return false;
+}
+
+static bool virtnet_validate_duplex(u8 duplex)
+{
+	switch (duplex) {
+	case DUPLEX_FULL:
+	case DUPLEX_UNKNOWN:
+		return true;
+	}
+
+	return false;
+}
+
+static int virtnet_set_settings(struct net_device *dev, struct ethtool_cmd
*cmd)
+{
+	struct virtnet_info *vi = netdev_priv(dev);
+	u32 speed = ethtool_cmd_speed(cmd);
+
+	/* don't allow custom speed and duplex */
+	if (!virtnet_validate_speed(speed) ||
+	    !virtnet_validate_duplex(cmd->duplex))
+		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;
+
+	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 +1453,8 @@ 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 +1927,8 @@ 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");
-- 
2.4.3

On 02/02/2016 01:51 PM, Nikolay Aleksandrov wrote:
> From: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
> 
> This patch allows the user to set and retrieve speed and duplex of the
> virtio_net device via ethtool. Having this functionality is very helpful
> for simulating different environments and also enables the virtio_net
> device to participate in operations where proper speed and duplex are
> required (e.g. currently bonding lacp mode requires full duplex). Custom
> speed and duplex are not allowed, the user-supplied settings are validated
> before applying. Only full and unknown duplex are allowed to be set.
> 
> Example:
> $ ethtool eth1
> Settings for eth1:
> ...
> 	Speed: Unknown!
> 	Duplex: Unknown! (255)
> $ ethtool -s eth1 speed 1000 duplex full
> $ ethtool eth1
> Settings for eth1:
> ...
> 	Speed: 1000Mb/s
> 	Duplex: Full
> 
> Based on a patch by Roopa Prabhu.
> 
> CC: Roopa Prabhu <roopa at cumulusnetworks.com>
> CC: Michael S. Tsirkin <mst at redhat.com>
> CC: virtualization at lists.linux-foundation.org
> Signed-off-by: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
> ---
> Allowed to set unknown speed/duplex if the user wants to reset them, though
> the user-space ethtool tool currently doesn't allow setting them.
> 
Since the speed can be anything maybe we should allow custom speeds after all ?
I wasn't sure about that so I added the validation.

Thanks,
 Nik

On Tue, Feb 02, 2016 at 01:51:20PM +0100, Nikolay Aleksandrov
wrote:
> From: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
> 
> This patch allows the user to set and retrieve speed and duplex of the
> virtio_net device via ethtool. Having this functionality is very helpful
> for simulating different environments and also enables the virtio_net
> device to participate in operations where proper speed and duplex are
> required (e.g. currently bonding lacp mode requires full duplex). Custom
> speed and duplex are not allowed, the user-supplied settings are validated
> before applying. Only full and unknown duplex are allowed to be set.
Why isn't half duplex legal?
> 
> Example:
> $ ethtool eth1
> Settings for eth1:
> ...
> 	Speed: Unknown!
> 	Duplex: Unknown! (255)
> $ ethtool -s eth1 speed 1000 duplex full
> $ ethtool eth1
> Settings for eth1:
> ...
> 	Speed: 1000Mb/s
> 	Duplex: Full
> 
> Based on a patch by Roopa Prabhu.
> 
> CC: Roopa Prabhu <roopa at cumulusnetworks.com>
> CC: Michael S. Tsirkin <mst at redhat.com>
> CC: virtualization at lists.linux-foundation.org
> Signed-off-by: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
Thanks!
Looks ok with one comment, see below.
> ---
> Allowed to set unknown speed/duplex if the user wants to reset them, though
> the user-space ethtool tool currently doesn't allow setting them.
> 
>  drivers/net/virtio_net.c | 74
++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 74 insertions(+)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 767ab11a6e9f..722ade567ee5 100644
> --- a/drivers/net/virtio_net.c
> +++ b/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 +1380,72 @@ static void virtnet_get_channels(struct net_device
*dev,
>  	channels->other_count = 0;
>  }
>  
> +static bool virtnet_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 true;
> +	}
> +
> +	return false;
> +}
> +
> +static bool virtnet_validate_duplex(u8 duplex)
> +{
> +	switch (duplex) {
> +	case DUPLEX_FULL:
> +	case DUPLEX_UNKNOWN:
> +		return true;
> +	}
> +
> +	return false;
> +}
Let's put the validating functions near where the
enums are defined so people remember to extend these
when adding new speeds?
Will help e.g. tun reuse this, too.
> +
> +static int virtnet_set_settings(struct net_device *dev, struct ethtool_cmd
*cmd)
> +{
> +	struct virtnet_info *vi = netdev_priv(dev);
> +	u32 speed = ethtool_cmd_speed(cmd);
> +
> +	/* don't allow custom speed and duplex */
> +	if (!virtnet_validate_speed(speed) ||
> +	    !virtnet_validate_duplex(cmd->duplex))
> +		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;
> +
> +	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 +1453,8 @@ 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 +1927,8 @@ 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");
> -- 
> 2.4.3

On 02/02/2016 02:23 PM, Michael S. Tsirkin wrote:
> On Tue, Feb 02, 2016 at 01:51:20PM +0100, Nikolay Aleksandrov wrote:
>> From: Nikolay Aleksandrov <nikolay at cumulusnetworks.com>
>>
>> This patch allows the user to set and retrieve speed and duplex of the
>> virtio_net device via ethtool. Having this functionality is very
helpful
>> for simulating different environments and also enables the virtio_net
>> device to participate in operations where proper speed and duplex are
>> required (e.g. currently bonding lacp mode requires full duplex).
Custom
>> speed and duplex are not allowed, the user-supplied settings are
validated
>> before applying. Only full and unknown duplex are allowed to be set.
> 
> Why isn't half duplex legal?
> 
It is legal, I'm just not sure it makes sense. Isn't the virtual channel
always "full duplex" ?
At first I had allowed it, but then I decided against and removed it. I
don't mind adding it back though, the argument against is not strong.
>>
>> Example:
>> $ ethtool eth1
>> Settings for eth1:
>> ...
>> 	Speed: Unknown!
>> 	Duplex: Unknown! (255)
>> $ ethtool -s eth1 speed 1000 duplex full
>> $ ethtool eth1
>> Settings for eth1:
>> ...
>> 	Speed: 1000Mb/s
>> 	Duplex: Full
>>
>> Based on a patch by Roopa Prabhu.
>>
>> CC: Roopa Prabhu <roopa at cumulusnetworks.com>
>> CC: Michael S. Tsirkin <mst at redhat.com>
>> CC: virtualization at lists.linux-foundation.org
>> Signed-off-by: Nikolay Aleksandrov <nikolay at
cumulusnetworks.com>
> 
> Thanks!
> Looks ok with one comment, see below.
> 
>> ---
>> Allowed to set unknown speed/duplex if the user wants to reset them,
though
>> the user-space ethtool tool currently doesn't allow setting them.
>>
>>  drivers/net/virtio_net.c | 74
++++++++++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 74 insertions(+)
>>
>> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
>> index 767ab11a6e9f..722ade567ee5 100644
>> --- a/drivers/net/virtio_net.c
>> +++ b/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 +1380,72 @@ static void virtnet_get_channels(struct
net_device *dev,
>>  	channels->other_count = 0;
>>  }
>>  
>> +static bool virtnet_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 true;
>> +	}
>> +
>> +	return false;
>> +}
>> +
>> +static bool virtnet_validate_duplex(u8 duplex)
>> +{
>> +	switch (duplex) {
>> +	case DUPLEX_FULL:
>> +	case DUPLEX_UNKNOWN:
>> +		return true;
>> +	}
>> +
>> +	return false;
>> +}
> 
> Let's put the validating functions near where the
> enums are defined so people remember to extend these
> when adding new speeds?
> Will help e.g. tun reuse this, too.
> 
Right, very good suggestion. I'll split this patch in two and will
add them for everyone to use.

Thank you,
 Nik
>> +
>> +static int virtnet_set_settings(struct net_device *dev, struct
ethtool_cmd *cmd)
>> +{
>> +	struct virtnet_info *vi = netdev_priv(dev);
>> +	u32 speed = ethtool_cmd_speed(cmd);
>> +
>> +	/* don't allow custom speed and duplex */
>> +	if (!virtnet_validate_speed(speed) ||
>> +	    !virtnet_validate_duplex(cmd->duplex))
>> +		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;
>> +
>> +	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 +1453,8 @@ 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 +1927,8 @@ 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");
>> -- 
>> 2.4.3

On Tue,  2 Feb 2016 13:51:20 +0100
Nikolay Aleksandrov <razor at blackwall.org> wrote:
> +static bool virtnet_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 true;
> +	}
> +
> +	return false;
> +}
Why limit to only known values. This switch() will get out of
date when some vendor introduces 64G or some other weird value.