On 10/11/2021 10:28 AM, Min Hu (Connor) wrote:
From: Huisong Li <lihuis...@huawei.com>

The dev->data->mac_addrs[0] will be changed to a new MAC address when
applications modify the default MAC address by
rte_eth_dev_default_mac_addr_set() API. However, If the new default
MAC address has been added as a non-default MAC address by
rte_eth_dev_mac_addr_add() API, the rte_eth_dev_default_mac_addr_set()
API doesn't remove it from dev->data->mac_addrs[]. As a result, one MAC
address occupies two index capacities in dev->data->mac_addrs[].


Hi Connor,

I see the problem, but can you please clarify what is the impact to the end 
user?

If application does as following:
  rte_eth_dev_mac_addr_add(MAC1);
  rte_eth_dev_mac_addr_add(MAC2);
  rte_eth_dev_mac_addr_add(MAC3);
  rte_eth_dev_default_mac_addr_set(MAC2);

The 'dev->data->mac_addrs[]' will have: "MAC2,MAC2,MAC3" which has 'MAC2' 
duplicated.

Will this cause any problem for the application to receive the packets
with 'MAC2' address?

Or is the only problem one extra space used in 'dev->data->mac_addrs[]'
without any other impact to the application?

This patch adds the logic of removing MAC addresses for this scenario.

Fixes: 854d8ad4ef68 ("ethdev: add default mac address modifier")
Cc: sta...@dpdk.org

Signed-off-by: Huisong Li <lihuis...@huawei.com>
Signed-off-by: Min Hu (Connor) <humi...@huawei.com>
---
v2:
* fixed commit log.
---
  lib/ethdev/rte_ethdev.c | 15 +++++++++++++++
  1 file changed, 15 insertions(+)

diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
index 028907bc4b..7faff17d9a 100644
--- a/lib/ethdev/rte_ethdev.c
+++ b/lib/ethdev/rte_ethdev.c
@@ -4340,6 +4340,7 @@ int
  rte_eth_dev_default_mac_addr_set(uint16_t port_id, struct rte_ether_addr 
*addr)
  {
        struct rte_eth_dev *dev;
+       int index;
        int ret;
RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
@@ -4361,6 +4362,20 @@ rte_eth_dev_default_mac_addr_set(uint16_t port_id, 
struct rte_ether_addr *addr)
        if (ret < 0)
                return ret;
+ /*
+        * If the address has been added as a non-default MAC address by
+        * rte_eth_dev_mac_addr_add API, it should be removed from
+        * dev->data->mac_addrs[].
+        */
+       index = eth_dev_get_mac_addr_index(port_id, addr);
+       if (index > 0) {
+               /* remove address in NIC data structure */
+               rte_ether_addr_copy(&null_mac_addr,
+                                   &dev->data->mac_addrs[index]);
+               /* reset pool bitmap */
+               dev->data->mac_pool_sel[index] = 0;
+       }
+

Here only 'dev->data->mac_addrs[]' array is updated and it assumes
driver removes similar duplication itself, but I am not sure if this is
valid for all drivers.

If driver is not removing the duplicate in the HW configuration, the driver
config and 'dev->data->mac_addrs[]' will diverge, which is not good.

What about following logic to be sure HW configuration and
'dev->data->mac_addrs[]' is same:

  index = eth_dev_get_mac_addr_index(port_id, addr);
  if (index > 0)
      rte_eth_dev_mac_addr_remove(port_id, addr);
  (*dev->dev_ops->mac_addr_set)(dev, addr);

        /* Update default address in NIC data structure */
        rte_ether_addr_copy(addr, &dev->data->mac_addrs[0]);

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