net: Disable GRO_HW when generic XDP is installed on a device.

Hardware should not aggregate any packets when generic XDP is installed.

Cc: Ariel Elior <Ariel.Elior@cavium.com>
Cc: everest-linux-l2@cavium.com
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/dev.c b/net/core/dev.c
index 4b43f5dcabcd6640d35d430e5fb364bf693a2fdc..c7db399267693fbea29fb19710b2be0c7e8c0e77 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1542,6 +1542,23 @@ void dev_disable_lro(struct net_device *dev)
 }
 EXPORT_SYMBOL(dev_disable_lro);
 
+/**
+ *     dev_disable_gro_hw - disable HW Generic Receive Offload on a device
+ *     @dev: device
+ *
+ *     Disable HW Generic Receive Offload (GRO_HW) on a net device.  Must be
+ *     called under RTNL.  This is needed if Generic XDP is installed on
+ *     the device.
+ */
+static void dev_disable_gro_hw(struct net_device *dev)
+{
+       dev->wanted_features &= ~NETIF_F_GRO_HW;
+       netdev_update_features(dev);
+
+       if (unlikely(dev->features & NETIF_F_GRO_HW))
+               netdev_WARN(dev, "failed to disable GRO_HW!\n");
+}
+
 static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
                                   struct net_device *dev)
 {
@@ -4564,6 +4581,7 @@ static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
                } else if (new && !old) {
                        static_key_slow_inc(&generic_xdp_needed);
                        dev_disable_lro(dev);
+                       dev_disable_gro_hw(dev);
                }
                break;