Re: [PATCH 1/2] ixgbe: add XDP support for pass and drop actions

John Fastabend
2017-04-24T04:26:37Z

On 17-04-23 09:05 PM, Jakub Kicinski wrote:
> Hi!
>
> On Sun, 23 Apr 2017 18:31:19 -0700, John Fastabend wrote:
>> +static int ixgbe_xdp_setup(struct net_device *dev, struct bpf_prog *prog)
>> +{
>> + int i, frame_size = dev->mtu + ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN;
>> + struct ixgbe_adapter *adapter = netdev_priv(dev);
>> + struct bpf_prog *old_prog;
>> +
>> + if (adapter->flags & IXGBE_FLAG_SRIOV_ENABLED)
>> + return -EINVAL;
>> +
>> + if (adapter->flags & IXGBE_FLAG_DCB_ENABLED)
>> + return -EINVAL;
>> +
>> + /* verify ixgbe ring attributes are sufficient for XDP */
>> + for (i = 0; i < adapter->num_rx_queues; i++) {
>> + struct ixgbe_ring *ring = adapter->rx_ring[i];
>> +
>> + if (ring_is_rsc_enabled(ring))
>> + return -EINVAL;
>> +
>> + if (frame_size > ixgbe_rx_bufsz(ring))
>> + return -EINVAL;
>> + }
>
> I was just looking through the drivers, working on extended ack
> reporting, trying to bring out the driver XDP error messages out
> directly to iproute2. It seems that multiple drivers are only
> checking that MTU/buffer size is appropriate in the XDP_SETUP
> function, and ignore XDP in case user tries to change MTU later.
> And I think it's the same story with LRO?
>

Agreed we need to harden the drivers to changes post XDP init. I'll submit
a few follow on patches for the ixgbe devices in the morning.

Thanks,
John