[PATCH 2/2 net-next] net: drivers: set TSO/UFO offload option explicitly

[PATCH 2/2 net-next] net: drivers: set TSO/UFO offload option explicitly

[Shan Wei]

The device drivers should not use NETIF_F_ALL_TSO mask to set hw_features(or features),
but have to explicitly set offload option. Because, This would make drivers automatically
clain to support any new TSO feature an the moment of NETIF_F_ALL_TSO is expanded.

Some code style tuning. Just compile test. 

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
---
 drivers/net/loopback.c   |   18 ++++++++----------
 drivers/net/virtio_net.c |    9 ++++++---
 2 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index d70fb76..bfb6a4a 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -152,6 +152,9 @@ static const struct net_device_ops loopback_ops = {
 	.ndo_get_stats64 = loopback_get_stats64,
 };
 
+#define LOOPBACK_USER_FEATURES (NETIF_F_TSO | NETIF_F_TSO_ECN | \
+				NETIF_F_TSO6 | NETIF_F_UFO)
+
 /*
  * The loopback device is special. There is only one instance
  * per network namespace.
@@ -165,16 +168,11 @@ static void loopback_setup(struct net_device *dev)
 	dev->type		= ARPHRD_LOOPBACK;	/* 0x0001*/
 	dev->flags		= IFF_LOOPBACK;
 	dev->priv_flags	       &= ~IFF_XMIT_DST_RELEASE;
-	dev->hw_features	= NETIF_F_ALL_TSO | NETIF_F_UFO;
-	dev->features 		= NETIF_F_SG | NETIF_F_FRAGLIST
-		| NETIF_F_ALL_TSO
-		| NETIF_F_UFO
-		| NETIF_F_NO_CSUM
-		| NETIF_F_RXCSUM
-		| NETIF_F_HIGHDMA
-		| NETIF_F_LLTX
-		| NETIF_F_NETNS_LOCAL
-		| NETIF_F_VLAN_CHALLENGED;
+	dev->hw_features	= LOOPBACK_USER_FEATURES;
+	dev->features		= NETIF_F_SG | NETIF_F_FRAGLIST
+		| LOOPBACK_USER_FEATURES | NETIF_F_NO_CSUM | NETIF_F_RXCSUM
+		| NETIF_F_HIGHDMA | NETIF_F_LLTX
+		| NETIF_F_NETNS_LOCAL | NETIF_F_VLAN_CHALLENGED;
 	dev->ethtool_ops	= &loopback_ethtool_ops;
 	dev->header_ops		= &eth_header_ops;
 	dev->netdev_ops		= &loopback_ops;
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 0cb0b06..addde86 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -875,6 +875,9 @@ static void virtnet_config_changed(struct virtio_device *vdev)
 	virtnet_update_status(vi);
 }
 
+#define VIRTNET_USER_FEATURES (NETIF_F_TSO | NETIF_F_TSO_ECN | \
+			       NETIF_F_TSO6 | NETIF_F_UFO)
+
 static int virtnet_probe(struct virtio_device *vdev)
 {
 	int err;
@@ -904,8 +907,7 @@ static int virtnet_probe(struct virtio_device *vdev)
 			dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST;
 
 		if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) {
-			dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO
-				| NETIF_F_TSO_ECN | NETIF_F_TSO6;
+			dev->hw_features |= VIRTNET_USER_FEATURES;
 		}
 		/* Individual feature bits: what can host handle? */
 		if (virtio_has_feature(vdev, VIRTIO_NET_F_HOST_TSO4))
@@ -918,7 +920,8 @@ static int virtnet_probe(struct virtio_device *vdev)
 			dev->hw_features |= NETIF_F_UFO;
 
 		if (gso)
-			dev->features |= dev->hw_features & (NETIF_F_ALL_TSO|NETIF_F_UFO);
+			dev->features |= dev->hw_features &
+					 VIRTNET_USER_FEATURES;
 		/* (!csum && gso) case will be fixed by register_netdev() */
 	}
 
-- 
1.7.3.1

Re: [PATCH 2/2 net-next] net: drivers: set TSO/UFO offload option explicitly

[Michał Mirosław]

2011/4/29 Shan Wei <shanwei@cn.fujitsu.com>:
> The device drivers should not use NETIF_F_ALL_TSO mask to set hw_features(or features),
> but have to explicitly set offload option. Because, This would make drivers automatically
> clain to support any new TSO feature an the moment of NETIF_F_ALL_TSO is expanded.
>
> Some code style tuning. Just compile test.
>
> Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
> ---
>  drivers/net/loopback.c   |   18 ++++++++----------
>  drivers/net/virtio_net.c |    9 ++++++---
>  2 files changed, 14 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
> index d70fb76..bfb6a4a 100644
> --- a/drivers/net/loopback.c
> +++ b/drivers/net/loopback.c
> @@ -152,6 +152,9 @@ static const struct net_device_ops loopback_ops = {
>        .ndo_get_stats64 = loopback_get_stats64,
>  };
>
> +#define LOOPBACK_USER_FEATURES (NETIF_F_TSO | NETIF_F_TSO_ECN | \
> +                               NETIF_F_TSO6 | NETIF_F_UFO)
> +
>  /*
>  * The loopback device is special. There is only one instance
>  * per network namespace.
> @@ -165,16 +168,11 @@ static void loopback_setup(struct net_device *dev)
>        dev->type               = ARPHRD_LOOPBACK;      /* 0x0001*/
>        dev->flags              = IFF_LOOPBACK;
>        dev->priv_flags        &= ~IFF_XMIT_DST_RELEASE;
> -       dev->hw_features        = NETIF_F_ALL_TSO | NETIF_F_UFO;
> -       dev->features           = NETIF_F_SG | NETIF_F_FRAGLIST
> -               | NETIF_F_ALL_TSO
> -               | NETIF_F_UFO
> -               | NETIF_F_NO_CSUM
> -               | NETIF_F_RXCSUM
> -               | NETIF_F_HIGHDMA
> -               | NETIF_F_LLTX
> -               | NETIF_F_NETNS_LOCAL
> -               | NETIF_F_VLAN_CHALLENGED;
> +       dev->hw_features        = LOOPBACK_USER_FEATURES;
> +       dev->features           = NETIF_F_SG | NETIF_F_FRAGLIST
> +               | LOOPBACK_USER_FEATURES | NETIF_F_NO_CSUM | NETIF_F_RXCSUM
> +               | NETIF_F_HIGHDMA | NETIF_F_LLTX
> +               | NETIF_F_NETNS_LOCAL | NETIF_F_VLAN_CHALLENGED;
>        dev->ethtool_ops        = &loopback_ethtool_ops;
>        dev->header_ops         = &eth_header_ops;
>        dev->netdev_ops         = &loopback_ops;

You can add NETIF_F_HIGHDMA and NETIF_F_NO_CSUM to
LOOPBACK_USER_FEATURES in one go. NETIF_F_RXCSUM could match
NETIF_F_NO_CSUM state (this needs ndo_fix_features callback), but this
won't have much real functional impact.

Best Regards,
Michał Mirosław

Re: [PATCH 2/2 net-next] net: drivers: set TSO/UFO offload option explicitly

[Shan Wei]

Michał Mirosław wrote, at 05/04/2011 08:36 PM:
> 2011/4/29 Shan Wei <shanwei@cn.fujitsu.com>:
>> The device drivers should not use NETIF_F_ALL_TSO mask to set hw_features(or features),
>> but have to explicitly set offload option. Because, This would make drivers automatically
>> clain to support any new TSO feature an the moment of NETIF_F_ALL_TSO is expanded.
>>
>> Some code style tuning. Just compile test.
>>
>> Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
>> ---
>>  drivers/net/loopback.c   |   18 ++++++++----------
>>  drivers/net/virtio_net.c |    9 ++++++---
>>  2 files changed, 14 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
>> index d70fb76..bfb6a4a 100644
>> --- a/drivers/net/loopback.c
>> +++ b/drivers/net/loopback.c
>> @@ -152,6 +152,9 @@ static const struct net_device_ops loopback_ops = {
>>        .ndo_get_stats64 = loopback_get_stats64,
>>  };
>>
>> +#define LOOPBACK_USER_FEATURES (NETIF_F_TSO | NETIF_F_TSO_ECN | \
>> +                               NETIF_F_TSO6 | NETIF_F_UFO)
>> +
>>  /*
>>  * The loopback device is special. There is only one instance
>>  * per network namespace.
>> @@ -165,16 +168,11 @@ static void loopback_setup(struct net_device *dev)
>>        dev->type               = ARPHRD_LOOPBACK;      /* 0x0001*/
>>        dev->flags              = IFF_LOOPBACK;
>>        dev->priv_flags        &= ~IFF_XMIT_DST_RELEASE;
>> -       dev->hw_features        = NETIF_F_ALL_TSO | NETIF_F_UFO;
>> -       dev->features           = NETIF_F_SG | NETIF_F_FRAGLIST
>> -               | NETIF_F_ALL_TSO
>> -               | NETIF_F_UFO
>> -               | NETIF_F_NO_CSUM
>> -               | NETIF_F_RXCSUM
>> -               | NETIF_F_HIGHDMA
>> -               | NETIF_F_LLTX
>> -               | NETIF_F_NETNS_LOCAL
>> -               | NETIF_F_VLAN_CHALLENGED;
>> +       dev->hw_features        = LOOPBACK_USER_FEATURES;
>> +       dev->features           = NETIF_F_SG | NETIF_F_FRAGLIST
>> +               | LOOPBACK_USER_FEATURES | NETIF_F_NO_CSUM | NETIF_F_RXCSUM
>> +               | NETIF_F_HIGHDMA | NETIF_F_LLTX
>> +               | NETIF_F_NETNS_LOCAL | NETIF_F_VLAN_CHALLENGED;
>>        dev->ethtool_ops        = &loopback_ethtool_ops;
>>        dev->header_ops         = &eth_header_ops;
>>        dev->netdev_ops         = &loopback_ops;
> 
> You can add NETIF_F_HIGHDMA and NETIF_F_NO_CSUM to
> LOOPBACK_USER_FEATURES in one go. NETIF_F_RXCSUM could match
> NETIF_F_NO_CSUM state (this needs ndo_fix_features callback), but this
> won't have much real functional impact.

Do you mean that defining LOOPBACK_USER_FEATURES as:
#define LOOPBACK_USER_FEATURES (NETIF_F_TSO | NETIF_F_TSO_ECN | \
                               NETIF_F_TSO6 | NETIF_F_UFO | NETIF_F_HIGHDMA | NETIF_F_NO_CSUM)

Is it necessary to add NETIF_F_NO_CSUM to hw_features?
After that, user can change TX hw csum offload(NETIF_F_NO_CSUM is disabled). But, this is not surportted before.

-- 
Best Regards
-----
Shan Wei

Re: [PATCH 2/2 net-next] net: drivers: set TSO/UFO offload option explicitly

[David Miller]

From: Shan Wei <shanwei@cn.fujitsu.com>
Date: Fri, 29 Apr 2011 13:34:45 +0800

> The device drivers should not use NETIF_F_ALL_TSO mask to set hw_features(or features),
> but have to explicitly set offload option. Because, This would make drivers automatically
> clain to support any new TSO feature an the moment of NETIF_F_ALL_TSO is expanded.
> 
> Some code style tuning. Just compile test. 
> 
> Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>

But loopback is special.  It can support anything the kernel stack can emit.

So for loopback, using NETIF_F_ALL_TSO is in fact appropriate.