Subject: Re: [Intel-wired-lan] [next-queue v6 PATCH 5/7] i40e: Add TX and RX support over port netdev's in switchdev mode

From: "Samudrala, Sridhar" <[email-masked]>
Date: Fri, 14 Apr 2017 11:26:25 -0700

On 4/14/2017 9:47 AM, Alexander Duyck wrote:
> On Wed, Mar 29, 2017 at 5:22 PM, Sridhar Samudrala
> <[email-masked]> wrote:
>> In switchdev mode, broadcasts from VFs are received by the PF and passed
>> to corresponding port representor netdev.
>> Any frames sent via port netdevs are sent as directed transmits to the
>> corresponding VFs. To enable directed transmit, skb metadata dst is used
>> to pass the port id and the frame is requeued to call the PFs transmit
>> routine. VF id is used as port id for VFs and PF port id is defined as
>> I40_MAIN_VSI_PORT_ID.
>>
>> Small script to demonstrate inter VF and PF to VF pings in switchdev mode.
>> PF: p4p1, VFs: p4p1_0,p4p1_1 VF Port Reps:p4p1-vf0, p4p1-vf1
>> PF Port rep: p4p1-pf
>>
>> # rmmod i40e; modprobe i40e
>> # devlink dev eswitch set pci/0000:05:00.0 mode switchdev
>> # echo 2 > /sys/class/net/p4p1/device/sriov_numvfs
>> # ip link set p4p1 vf 0 mac 00:11:22:33:44:55
>> # ip link set p4p1 vf 1 mac 00:11:22:33:44:56
>> # rmmod i40evf; modprobe i40evf
>>
>> /* Create 2 namespaces and move the VFs to the corresponding ns */
>> # ip netns add ns0
>> # ip link set p4p1_0 netns ns0
>> # ip netns exec ns0 ip addr add 192.168.1.10/24 dev p4p1_0
>> # ip netns exec ns0 ip link set p4p1_0 up
>> # ip netns add ns1
>> # ip link set p4p1_1 netns ns1
>> # ip netns exec ns1 ip addr add 192.168.1.11/24 dev p4p1_1
>> # ip netns exec ns1 ip link set p4p1_1 up
>>
>> /* bring up pf and port netdevs */
>> # ip addr add 192.168.1.1/24 dev p4p1
>> # ip link set p4p1 up
>> # ip link set p4p1-vf0 up
>> # ip link set p4p1-vf1 up
>> # ip link set p4p1-pf up
>>
>> # ip netns exec ns0 ping -c3 192.168.1.11  /* VF0 -> VF1 */
>> # ip netns exec ns1 ping -c3 192.168.1.10  /* VF1 -> VF0 */
>> # ping -c3 192.168.1.10   /* PF -> VF0 */
>> # ping -c3 192.168.1.11   /* PF -> VF1 */
>>
>> /* VF0 -> IP in same subnet - broadcasts will be seen on p4p1-vf0 & p4p1 */
>> # ip netns exec ns0 ping -c1 -W1 192.168.1.200
>> /* VF1 -> IP in same subnet -  broadcasts will be seen on p4p1-vf1 & p4p1*/
>> # ip netns exec ns0 ping -c1 -W1 192.168.1.200
>> /* port rep VF0 -> IP in same subnet - broadcasts will be seen on p4p1_0 */
>> # ping -I p4p1-vf0 -c1 -W1 192.168.1.200
>> /* port rep VF1 -> IP in same subnet  - broadcasts will be seen on p4p1_1 */
>> # ping -I p4p1-vf1 -c1 -W1 192.168.1.200
>>
>> Signed-off-by: Sridhar Samudrala <[email-masked]>
>> ---
>>   drivers/net/ethernet/intel/i40e/i40e.h             |   4 +
>>   drivers/net/ethernet/intel/i40e/i40e_main.c        |  27 +++-
>>   drivers/net/ethernet/intel/i40e/i40e_txrx.c        | 148 ++++++++++++++++++++-
>>   drivers/net/ethernet/intel/i40e/i40e_txrx.h        |   2 +
>>   drivers/net/ethernet/intel/i40e/i40e_type.h        |   3 +
>>   drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c |   8 +-
>>   6 files changed, 184 insertions(+), 8 deletions(-)
>>
> <snip>
>
>> diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
>> index ebffca0..86d2510 100644
>> --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
>> +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
>> @@ -1302,20 +1302,64 @@ static bool i40e_alloc_mapped_page(struct i40e_ring *rx_ring,
>>   }
>>
>>   /**
>> + * i40e_handle_lpbk_skb - Update skb->dev of a loopback frame
>> + * @rx_ring: rx ring in play
>> + * @skb: packet to send up
>> + **/
>> +static void i40e_handle_lpbk_skb(struct i40e_ring *rx_ring, struct sk_buff *skb)
>> +{
>> +       struct i40e_q_vector *q_vector = rx_ring->q_vector;
>> +       struct i40e_pf *pf = rx_ring->vsi->back;
>> +       struct sk_buff *nskb;
>> +       struct i40e_vf *vf;
>> +       struct ethhdr *eth;
>> +       int vf_id;
>> +
>> +       if ((skb->pkt_type != PACKET_BROADCAST) &&
>> +           (skb->pkt_type != PACKET_MULTICAST) &&
>> +           (skb->pkt_type != PACKET_OTHERHOST))
>> +               return;
>> +
>> +       eth = (struct ethhdr *)skb_mac_header(skb);
>> +
>> +       /* If a loopback packet is received in switchdev mode, clone the skb
>> +        * and pass it to the corresponding port netdev based on the source MAC.
>> +        */
>> +       for (vf_id = 0; vf_id < pf->num_alloc_vfs; vf_id++) {
>> +               vf = &pf->vf[vf_id];
>> +               if (ether_addr_equal(eth->h_source,
>> +                                    vf->default_lan_addr.addr)) {
>> +                       nskb = skb_clone(skb, GFP_ATOMIC);
>> +                       if (!nskb)
>> +                               break;
>> +                       nskb->offload_fwd_mark = 1;
> So this line is causing build errors when switchdev is not enabled.
> This whole function should probably be wrapped in a check to see if
> switchdev support is enabled or not.
Yes. will fix it in the next revision.

Thanks
Sridhar