v1: http://patchwork.ozlabs.org/patch/296062/ v2: http://patchwork.ozlabs.org/patch/296144/

0001-macvlan-Support-creating-macvtaps-from-macvlans.patch

From ecbfba5bfd8f84511793901a2f82210c8db08213 Mon Sep 17 00:00:00 2001
From: Kevin Wallace <kevin@pentabarf.net>
Date: Tue, 3 Dec 2013 01:45:13 -0800
Subject: [PATCH] macvlan: Support creating macvtaps from macvlans

When running in a network namespace whose only link to the outside
world is a macvlan device, not being able to create a macvtap off of
it is a real pain.

So modify macvtap creation to automatically forward a creation of a
macvtap on a macvlan to become a creation of a macvtap on the
underlying network device, just like is currently done with
macvlan-on-macvlan devices.

v2: Use netif_is_macvlan and macvlan_dev_real_dev helpers to make it
    more clear what we're doing.

Signed-off-by: Kevin Wallace <kevin@pentabarf.net>
---
 drivers/net/macvlan.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index acf9379..cfb9157 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -820,13 +820,11 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
 	if (lowerdev == NULL)
 		return -ENODEV;
 
-	/* When creating macvlans on top of other macvlans - use
+	/* When creating macvlans or macvtaps on top of other macvlans - use
 	 * the real device as the lowerdev.
 	 */
-	if (lowerdev->rtnl_link_ops == dev->rtnl_link_ops) {
-		struct macvlan_dev *lowervlan = netdev_priv(lowerdev);
-		lowerdev = lowervlan->lowerdev;
-	}
+	if (netif_is_macvlan(lowerdev))
+		lowerdev = macvlan_dev_real_dev(lowerdev);
 
 	if (!tb[IFLA_MTU])
 		dev->mtu = lowerdev->mtu;
-- 
1.8.3.2