macvlan: allow setting LRO independently of lower device

Since commit fbe168ba91f7 ("net: generic dev_disable_lro() stacked
device handling"), dev_disable_lro() zeroes NETIF_F_LRO feature flag
first for a macvlan device and then for its lower device. As an attempt
to set NETIF_F_LRO to zero is ignored, dev_disable_lro() issues a
warning and taints kernel.

Allowing NETIF_F_LRO to be set independently of the lower device
consists of three parts:

  - add the flag to hw_features to allow toggling it
  - allow setting it to 0 even if lower device has the flag set
  - add the flag to MACVLAN_FEATURES to restore copying from lower
    device on macvlan creation

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 4 deletions

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 9538674587aa..10604db2a3a0 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -747,7 +747,7 @@ static struct lock_class_key macvlan_netdev_addr_lock_key;
 
 #define MACVLAN_FEATURES \
         (NETIF_F_SG | NETIF_F_ALL_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \
-         NETIF_F_GSO | NETIF_F_TSO | NETIF_F_UFO | \
+         NETIF_F_GSO | NETIF_F_TSO | NETIF_F_UFO | NETIF_F_LRO | \
          NETIF_F_TSO_ECN | NETIF_F_TSO6 | NETIF_F_GRO | NETIF_F_RXCSUM | \
          NETIF_F_HW_VLAN_CTAG_FILTER | NETIF_F_HW_VLAN_STAG_FILTER)
 
@@ -784,6 +784,7 @@ static int macvlan_init(struct net_device *dev)
                                   (lowerdev->state & MACVLAN_STATE_MASK);
         dev->features           = lowerdev->features & MACVLAN_FEATURES;
         dev->features           |= ALWAYS_ON_FEATURES;
+        dev->hw_features        |= NETIF_F_LRO;
         dev->vlan_features      = lowerdev->vlan_features & MACVLAN_FEATURES;
         dev->gso_max_size       = lowerdev->gso_max_size;
         dev->iflink             = lowerdev->ifindex;
@@ -936,15 +937,15 @@ static netdev_features_t macvlan_fix_features(struct net_device *dev,
                                               netdev_features_t features)
 {
         struct macvlan_dev *vlan = netdev_priv(dev);
+        netdev_features_t lowerdev_features = vlan->lowerdev->features;
         netdev_features_t mask;
 
         features |= NETIF_F_ALL_FOR_ALL;
         features &= (vlan->set_features | ~MACVLAN_FEATURES);
         mask = features;
 
-        features = netdev_increment_features(vlan->lowerdev->features,
-                                             features,
-                                             mask);
+        lowerdev_features &= (features | ~NETIF_F_LRO);
+        features = netdev_increment_features(lowerdev_features, features, mask);
         features |= ALWAYS_ON_FEATURES;
         features &= ~NETIF_F_NETNS_LOCAL;