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>

1 files changed, 18 insertions, 0 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 4b43f5dcabcd..c7db39926769 100644
--- 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;