[ovs-dev] OVS to set Virtual Function MAC address

[Ilya Maximets]

On 23.06.2019 17:37, Hamdy Khader wrote:
> We are working on adding the ability to create VM with DPDK Representor port in OpenStack environment,
> that means as part of port plugging flow, the port's MAC address will be generated on VM spawning,
> and need to be set to the VF.
> 
> Usually we use python libraries like os-vif or pyroute2 to set the VF's MAC address for bifurcated drivers (e.g. Mellanox NIC) but we are facing a problem setting the MAC for non-bifurcated drivers (e.g. I40E).

In usual SRIOV configurations with OpenStack Nova sets the VF mac into
libvirt XML and Libvirt administratively sets VF mac while VM launching.
So, in usual cases, libvirt is responsible for setting VF mac.
I understand your issue with DPDK controlled PF. Libvirt might not be able
to set VF mac while PF is attached to DPDK. But, IIRC, libvirt will fail
to pass VF to VM if it will not find the PF linux network device on host.
So, you, probably, have much worse issues than just setting the MAC.

BTW, setting the MAC to dpdk devices could be implemented by something
like this (not tested):

diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
index 4856c56aa..228d943be 100644
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -2507,11 +2507,24 @@ static int
 netdev_dpdk_set_etheraddr(struct netdev *netdev, const struct eth_addr mac)
 {
     struct netdev_dpdk *dev = netdev_dpdk_cast(netdev);
+    int err = 0;
 
     ovs_mutex_lock(&dev->mutex);
     if (!eth_addr_equals(dev->hwaddr, mac)) {
-        dev->hwaddr = mac;
-        netdev_change_seq_changed(netdev);
+        if (dev->type == DPDK_DEV_ETH) {
+            struct ether_addr ea;
+
+            memcpy(ea.addr_bytes, mac.ea, ETH_ADDR_LEN);
+            err = rte_eth_dev_default_mac_addr_set(dev->port_id, &ea);
+        }
+        if (!err) {
+            dev->hwaddr = mac;
+            netdev_change_seq_changed(netdev);
+        } else {
+            VLOG_WARN("%s: Failed to set requested mac("ETH_ADDR_FMT"): %s",
+                      netdev_get_name(netdev), ETH_ADDR_ARGS(mac),
+                      rte_strerror(-err));
+        }
     }
     ovs_mutex_unlock(&dev->mutex);
 
---

I'm not sure if it will work (if we able to change default MAC while port is
started? Or we should request the reconfiguration for this?) and why we didn't
set the mac to HW previously.

Best regards, Ilya Maximets.

> 
> OVS-DPDK supports both types of drivers for DPDK representor ports and I think OVS should set the MAC (if provided) as part of DPDK port addition.
> 
> Below you can find DPDK representor port info, "attached-mac" is the desired value to be used as VF MAC.
> 
> # ovs-vsctl list Interface vfrff9715cc-ee
> _uuid               : c4b5aa06-3a3c-4ff4-a5a0-eeac028ac2f4
> admin_state         : up
> bfd                 : {}
> bfd_status          : {}
> cfm_fault           : []
> cfm_fault_status    : []
> cfm_flap_count      : []
> cfm_health          : []
> cfm_mpid            : []
> cfm_remote_mpids    : []
> cfm_remote_opstate  : []
> duplex              : full
> error               : []
> external_ids        : {attached-mac="fa:16:3e:65:3d:0c", iface-id="ff9715cc-ee22-4f02-b57b-ac2a1707248a", iface-status=active, vm-uuid="e9a2ac9d-663b-4bdb-907a-b50aa3a238a9"}
> ifindex             : 1277170
> ingress_policing_burst: 0
> ingress_policing_rate: 0
> lacp_current        : []
> link_resets         : 0
> link_speed          : 10000000000
> link_state          : up
> lldp                : {}
> mac                 : []
> mac_in_use          : "a2:e4:6e:d6:ff:86"
> mtu                 : 1500
> mtu_request         : []
> name                : "vfrff9715cc-ee"
> ofport              : 15
> ofport_request      : []
> options             : {dpdk-devargs="0000:02:00.1,representor=[15]"}
> other_config        : {}
> statistics          : {rx_bytes=8638, rx_dropped=0, rx_errors=0, rx_mbuf_allocation_errors=0, rx_missed_errors=0, rx_packets=31, tx_bytes=10010, tx_dropped=0, tx_errors=0, tx_packets=143}
> status              : {driver_name="net_mlx5", if_descr="DPDK 18.11.0 net_mlx5", if_type="6", link_speed="10Gbps", max_hash_mac_addrs="0", max_mac_addrs="128", max_rx_pktlen="1518", max_rx_queues="65535", max_tx_queues="65535", max_vfs="0", max_vmdq_pools="0", min_rx_bufsize="32", numa_id="0", pci-device_id="0x1015", pci-vendor_id="0x15b3", port_no="1"}
> type                : dpdk
> 
> ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
> *From:* Stokes, Ian <ian.stokes at intel.com>
> *Sent:* Sunday, June 23, 2019 4:06 PM
> *To:* Hamdy Khader; dev at openvswitch.org
> *Cc:* Ilya Maximets; Ophir Munk
> *Subject:* RE: OVS to set Virtual Function MAC address
>  
>> Hi,
>> 
>> I'm working with DPDK representor ports to integrate it with OpenStack and
>> I have to assign the MAC for the VF using "ip" command.
>> 
>> Are there plans to make OVS to set the VFs MAC when we add dpdk
>> representor port?
> 
> Not that I'm aware of, I would think setting MACs etc. would be an administrator task during deployment carried out by something like IP (as you have done already). Is there a reason why you feel OVS should do this task?
> 
> Regards
> Ian