[PATCH] ibmveth: Add function to enable live MAC address changes

[PATCH] ibmveth: Add function to enable live MAC address changes

[Thomas Falcon]

Add a function that will enable changing the MAC address
of an ibmveth interface while it is still running.

Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
---
 drivers/net/ethernet/ibm/ibmveth.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c
index 21978cc..6e44357 100644
--- a/drivers/net/ethernet/ibm/ibmveth.c
+++ b/drivers/net/ethernet/ibm/ibmveth.c
@@ -1327,6 +1327,24 @@ static unsigned long ibmveth_get_desired_dma(struct vio_dev *vdev)
 	return ret;
 }
 
+static int ibmveth_set_mac_addr(struct net_device *dev, void *p)
+{
+	struct ibmveth_adapter *adapter = netdev_priv(dev);
+	struct sockaddr *addr = p;
+	u64 mac_address;
+	int rc;
+
+	if (!is_valid_ether_addr(addr->sa_data))
+		return -EADDRNOTAVAIL;
+
+	ether_addr_copy(dev->dev_addr, addr->sa_data);
+
+	mac_address = ibmveth_encode_mac_addr(dev->dev_addr);
+	rc = h_change_logical_lan_mac(adapter->vdev->unit_address, mac_address);
+
+	return rc;
+}
+
 static const struct net_device_ops ibmveth_netdev_ops = {
 	.ndo_open		= ibmveth_open,
 	.ndo_stop		= ibmveth_close,
@@ -1337,7 +1355,7 @@ static const struct net_device_ops ibmveth_netdev_ops = {
 	.ndo_fix_features	= ibmveth_fix_features,
 	.ndo_set_features	= ibmveth_set_features,
 	.ndo_validate_addr	= eth_validate_addr,
-	.ndo_set_mac_address	= eth_mac_addr,
+	.ndo_set_mac_address    = ibmveth_set_mac_addr,
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	.ndo_poll_controller	= ibmveth_poll_controller,
 #endif
-- 
1.9.3

Re: [PATCH] ibmveth: Add function to enable live MAC address changes

[Brian King]

On 02/25/2015 06:34 PM, Thomas Falcon wrote:
> @@ -1327,6 +1327,24 @@ static unsigned long ibmveth_get_desired_dma(struct vio_dev *vdev)
>  	return ret;
>  }
> 
> +static int ibmveth_set_mac_addr(struct net_device *dev, void *p)
> +{
> +	struct ibmveth_adapter *adapter = netdev_priv(dev);
> +	struct sockaddr *addr = p;
> +	u64 mac_address;
> +	int rc;
> +
> +	if (!is_valid_ether_addr(addr->sa_data))
> +		return -EADDRNOTAVAIL;
> +
> +	ether_addr_copy(dev->dev_addr, addr->sa_data);
> +
> +	mac_address = ibmveth_encode_mac_addr(dev->dev_addr);
> +	rc = h_change_logical_lan_mac(adapter->vdev->unit_address, mac_address);
> +
> +	return rc;

Do you still want to be changing dev->dev_addr if h_change_logical_lan_mac
returns a failure?

-Brian

-- 
Brian King
Power Linux I/O
IBM Linux Technology Center

Re: [PATCH] ibmveth: Add function to enable live MAC address changes

[Jiri Pirko]

Thu, Feb 26, 2015 at 02:08:06PM CET, brking@linux.vnet.ibm.com wrote:
>On 02/25/2015 06:34 PM, Thomas Falcon wrote:
>> @@ -1327,6 +1327,24 @@ static unsigned long ibmveth_get_desired_dma(struct vio_dev *vdev)
>>  	return ret;
>>  }
>> 
>> +static int ibmveth_set_mac_addr(struct net_device *dev, void *p)
>> +{
>> +	struct ibmveth_adapter *adapter = netdev_priv(dev);
>> +	struct sockaddr *addr = p;
>> +	u64 mac_address;
>> +	int rc;
>> +
>> +	if (!is_valid_ether_addr(addr->sa_data))
>> +		return -EADDRNOTAVAIL;
>> +
>> +	ether_addr_copy(dev->dev_addr, addr->sa_data);
>> +
>> +	mac_address = ibmveth_encode_mac_addr(dev->dev_addr);
>> +	rc = h_change_logical_lan_mac(adapter->vdev->unit_address, mac_address);
>> +
>> +	return rc;
>
>Do you still want to be changing dev->dev_addr if h_change_logical_lan_mac
>returns a failure?

That should not be done. dev_addr should be in sync with real hw addr.

Re: [PATCH] ibmveth: Add function to enable live MAC address changes

[David Miller]

From: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
Date: Wed, 25 Feb 2015 18:34:24 -0600

> Add a function that will enable changing the MAC address
> of an ibmveth interface while it is still running.
> 
> Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
> ---
>  drivers/net/ethernet/ibm/ibmveth.c | 20 +++++++++++++++++++-
>  1 file changed, 19 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c
> index 21978cc..6e44357 100644
> --- a/drivers/net/ethernet/ibm/ibmveth.c
> +++ b/drivers/net/ethernet/ibm/ibmveth.c
> @@ -1327,6 +1327,24 @@ static unsigned long ibmveth_get_desired_dma(struct vio_dev *vdev)
>  	return ret;
>  }
>  
> +static int ibmveth_set_mac_addr(struct net_device *dev, void *p)
> +{
> +	struct ibmveth_adapter *adapter = netdev_priv(dev);
> +	struct sockaddr *addr = p;
> +	u64 mac_address;
> +	int rc;
> +
> +	if (!is_valid_ether_addr(addr->sa_data))
> +		return -EADDRNOTAVAIL;
> +
> +	ether_addr_copy(dev->dev_addr, addr->sa_data);
> +
> +	mac_address = ibmveth_encode_mac_addr(dev->dev_addr);
> +	rc = h_change_logical_lan_mac(adapter->vdev->unit_address, mac_address);

As others have said, if this hypervisor call fails you must not change
dev->dev_addr.  It must always be in sync with "the hardware."