During the mlx5_dev_spawn(), it tries to sync the MAC address of the Device to the internal MAC table. In case of SR-IOV VF , the mlx5_nl_mac_addr_sync() gets, 2 MAC address in the fresh start. One the unicast MAC assigned to the VF on the host and the second the multicast mac of 33:33:00:00:00:01. Currently without check the type of MAC we try to add the MAC 33:33:00:00:00:01 to the first free place in the MAC table which will be mostly index 1, as index 0 stores the unicast MAC assigned to the VF. This causes issues subsequently when we try to add multicast address list. As every IPv6 IP generates differnet multicast MAC, to support multiple IP on a single interface, we need to add a list of multicast MAC. As an example, if we try to add 3 multicast MAC as mentioned below mcast addr 0 - 33:33:00:00:00:01 mcast addr 1 - 01:00:5e:00:00:01 mcast addr 2 - 33:33:ff:68:fe:7d then, the addition of these MAC will fail with error -EADDRINUSE in mlx5_internal_mac_addr_add(), and none of the MAC address will be added to the device, which will lead of packet drop in case multicast promiscuous is not enable. To make this work, we should store the synced MAC to the proper section of the internal table, after checking the type of the MAC synced. This check will make the MAC of 33:33:00:00:00:01(synced MAC) to be stored at index 128(starting of MLX5_MAX_MC_MAC_ADDRESSES), which will be removed and added again during the mlx5_set_mc_addr_list(). This will make sure that all the multicast MACs are added properly to both the internal table and also the device, specially in case of SR-IOV VF.
Souvik Dey (1): net/mlx5:fix storing the synced MAC to internal table drivers/common/mlx5/linux/mlx5_nl.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) -- 2.9.3.windows.1
