Subject: Re: [PATCH net-next v9 7/7] ixgbevf: Add the appropriate ethtool ops to query RSS indirection table and key

From: Vlad Zolotarov <[email-masked]>
Date: Mon, 30 Mar 2015 17:00:04 +0300

On 03/30/15 01:19, Alexander Duyck wrote:
> On 03/29/2015 09:11 AM, Vlad Zolotarov wrote:
>> Added get_rxfh_indir_size, get_rxfh_key_size and get_rxfh ethtool_ops callbacks
>> implementations.
>>
>> This enables the ethtool's "-x" and "--show-rxfh[-indir]" options for VF devices.
>>
>> This patch adds the support for 82599 and x540 devices only. Support for other
>> devices will be added later.
>>
>> Signed-off-by: Vlad Zolotarov <[email-masked]>
>> ---
>> New in v9:
>>     - Use IXGBEVF_RSS_HASH_KEY_SIZE macro.
>>
>> New in v6:
>>     - Added a required get_rxnfc callback to ixgbevf_ethtool_ops.
>>
>> New in v4:
>>     - Removed not needed braces in if-statement in ixgbevf_get_rxfh_indir_size().
>>
>> New in v3:
>>     - Added a proper support for x550 devices: return the correct redirection table size.
>>
>> New in v2:
>>     - Added a detailed description to the patch.
>> ---
>>   drivers/net/ethernet/intel/ixgbevf/ethtool.c | 58 ++++++++++++++++++++++++++++
>>   1 file changed, 58 insertions(+)
>>
>> diff --git a/drivers/net/ethernet/intel/ixgbevf/ethtool.c b/drivers/net/ethernet/intel/ixgbevf/ethtool.c
>> index e83c85b..4d2f59f 100644
>> --- a/drivers/net/ethernet/intel/ixgbevf/ethtool.c
>> +++ b/drivers/net/ethernet/intel/ixgbevf/ethtool.c
>> @@ -794,6 +794,60 @@ static int ixgbevf_set_coalesce(struct net_device *netdev,
>>   	return 0;
>>   }
>>   
>> +static int ixgbevf_get_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info,
>> +			     u32 *rules __always_unused)
>> +{
>> +	struct ixgbevf_adapter *adapter = netdev_priv(dev);
>> +
>> +	switch (info->cmd) {
>> +	case ETHTOOL_GRXRINGS:
>> +		info->data = adapter->num_rx_queues;
>> +		return 0;
>> +	default:
>> +		hw_dbg(&adapter->hw, "Command parameters not supported\n");
>> +		return -EOPNOTSUPP;
>> +	}
>> +}
>> +
>> +static u32 ixgbevf_get_rxfh_indir_size(struct net_device *netdev)
>> +{
>> +	struct ixgbevf_adapter *adapter = netdev_priv(netdev);
>> +
>> +	if (adapter->hw.mac.type >= ixgbe_mac_X550_vf)
>> +		return 64;
>> +	else
>> +		return 128;
>> +}
>> +
> You should return 0 for x550, not 64 since it isn't supported.
>
> My suggestion would be to alter the code so that you return 128 for
> everything <= x540_vf, and place a return 0 as the default return
> without a need for the if statement.
ok
>
>> +static u32 ixgbevf_get_rxfh_key_size(struct net_device *netdev)
>> +{
>> +	return IXGBEVF_RSS_HASH_KEY_SIZE;
>> +}
>> +
> Same thing here.  If you don't support this on x550 you should probably
> return 0 instead of returning a value.
ok
>
>> +static int ixgbevf_get_rxfh(struct net_device *netdev, u32 *indir, u8 *key,
>> +			    u8 *hfunc)
>> +{
>> +	struct ixgbevf_adapter *adapter = netdev_priv(netdev);
>> +	int err;
>> +
>> +	if (hfunc)
>> +		*hfunc = ETH_RSS_HASH_TOP;
>> +
>> +	if (indir) {
>> +		err = ixgbevf_get_reta(adapter, indir);
>> +		if (err)
>> +			return err;
>> +	}
>> +
>> +	if (key) {
>> +		err = ixgbevf_get_rss_key(adapter, key);
>> +		if (err)
>> +			return err;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
> My advice here would be to just wrap these two functions in one mailbox
> lock and update the second check so that it is if (!err && key) so that
> you can simplify the path and just return err at the end.

Yeah, something like that. U see - no need to unite them... ;)

>
>>   static const struct ethtool_ops ixgbevf_ethtool_ops = {
>>   	.get_settings		= ixgbevf_get_settings,
>>   	.get_drvinfo		= ixgbevf_get_drvinfo,
>> @@ -811,6 +865,10 @@ static const struct ethtool_ops ixgbevf_ethtool_ops = {
>>   	.get_ethtool_stats	= ixgbevf_get_ethtool_stats,
>>   	.get_coalesce		= ixgbevf_get_coalesce,
>>   	.set_coalesce		= ixgbevf_set_coalesce,
>> +	.get_rxnfc		= ixgbevf_get_rxnfc,
>> +	.get_rxfh_indir_size	= ixgbevf_get_rxfh_indir_size,
>> +	.get_rxfh_key_size	= ixgbevf_get_rxfh_key_size,
>> +	.get_rxfh		= ixgbevf_get_rxfh,
>>   };
>>   
>>   void ixgbevf_set_ethtool_ops(struct net_device *netdev)
>>