On 01/05/2014 07:21 PM, Jason Wang wrote:
L2 fowarding offload will bypass the rx handler of real device. This will make
the packet could not be forwarded to macvtap device. Another problem is the
dev_hard_start_xmit() called for macvtap does not have any synchronization.
Fix this by forbidding L2 forwarding for macvtap.
Cc: John Fastabend <john.r.fastab...@intel.com>
Cc: Neil Horman <nhor...@tuxdriver.com>
Signed-off-by: Jason Wang <jasow...@redhat.com>
---
drivers/net/macvlan.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)
I must be missing something.
The lower layer device should set skb->dev to the correct macvtap
device on receive so that in netif_receive_skb_core() the macvtap
handler is hit. Skipping the macvlan receive handler should be OK
because the switching was done by the hardware. If I read macvtap.c
correctly macvlan_common_newlink() is called with 'dev' where 'dev'
is the macvtap device. Any idea what I'm missing? I guess I'll need
to setup a macvtap test case.
And what synchronization are you worried about on dev_hard_start_xmit()?
In the L2 forwarding offload case macvlan_open() clears the NETIF_F_LLTX
flag so HARD_TX_LOCK protects the driver txq. We might hit this warning
in dev_queue_xmit() though,
net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
Perhaps we can remove it.
diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 60406b0..5360f73 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -338,6 +338,8 @@ static const struct header_ops macvlan_hard_header_ops = {
.cache_update = eth_header_cache_update,
};
+static struct rtnl_link_ops macvlan_link_ops;
+
static int macvlan_open(struct net_device *dev)
{
struct macvlan_dev *vlan = netdev_priv(dev);
@@ -353,7 +355,8 @@ static int macvlan_open(struct net_device *dev)
goto hash_add;
}
- if (lowerdev->features & NETIF_F_HW_L2FW_DOFFLOAD) {
+ if (lowerdev->features & NETIF_F_HW_L2FW_DOFFLOAD &&
+ dev->rtnl_link_ops == &macvlan_link_ops) {
vlan->fwd_priv =
lowerdev->netdev_ops->ndo_dfwd_add_station(lowerdev, dev);
--
John Fastabend Intel Corporation
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