Re: [dpdk-dev] [PATCH] ethdev: fix one MAC address occupies two index in mac addrs

[Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>]

On 9/22/21 10:43 AM, Huisong Li wrote:
> 
> 在 2021/9/22 14:39, Andrew Rybchenko 写道:
>> On 9/22/21 6:36 AM, Min Hu (Connor) wrote:
>>> From: Huisong Li <lihuisong@huawei.com>
>>>
>>> Use the testpmd to perform the following operations:
>>> 1) mac_addr add 0 00:18:2D:00:00:90
>>> 2) mac_addr add 0 00:18:2D:00:00:91
>>> 3) mac_addr add 0 00:18:2D:00:00:92
>>> 4) mac_addr set 0 00:18:2D:00:00:91
>>> 5) show port 0 macs
>>> Number of MAC address added: 4
>>>    00:18:2D:00:00:91
>>>    00:18:2D:00:00:90
>>>    00:18:2D:00:00:91
>>>    00:18:2D:00:00:92
>>>
>>> This is due to the reason that if the address has been added as a
>>> non-default MAC address by rte_eth_dev_mac_addr_add API, it doesn't
>>> remove
>>> from dev->data->mac_addrs[] when set default MAC address with the same
>>> address.
>>>
>>> Fixes: 854d8ad4ef68 ("ethdev: add default mac address modifier")
>>> Cc: stable@dpdk.org
>>>
>>> Signed-off-by: Huisong Li <lihuisong@huawei.com>
>>> Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
>>> ---
>>>   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 daf5ca9242..77657a3314 100644
>>> --- a/lib/ethdev/rte_ethdev.c
>>> +++ b/lib/ethdev/rte_ethdev.c
>>> @@ -4360,6 +4360,7 @@ 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);
>>> @@ -4381,6 +4382,20 @@ 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;
>>> +    }
>>> +
>>>       /* Update default address in NIC data structure */
>>>       rte_ether_addr_copy(addr, &dev->data->mac_addrs[0]);
>>>  
>> If I change default MAC to something else later, should the old
>> default MAC be returned to some specific pools? I guess it is
> 
> Since the old default MAC address is invalid, which has been removed
> from hardware.
> 
> This MAC address does not need to be added to some specific pools, and
> occupies
> 
> one position in mac addrs.
> 
>> hard to do. If the change is accepted, the behaviour must be
>> documented in rte_eth_dev_default_mac_addr_set() description.
>> .
> 
> I think it's not necessary. Because old default MAC is no longer valid
> if we modify
> 
> default MAC with a new MAC address. This is a definition of
> rte_eth_dev_default_mac_addr_set().
> 
> The current modification does not change the definition of the interface.

Not sure that I understand:

set default MAC-A
add MAC-B to pool 1
set default MAC-B
set default MAC-C

since I've not removed MAC-B from pool 1, I'd expect it to be
there.