Re: [PATCH v4 1/2] ethdev: fix one address occupies two indexes in MAC addrs

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

Cc more driver maintainers

On 6/2/22 06:16, lihuisong (C) wrote:
> 
> 在 2022/6/2 1:49, Andrew Rybchenko 写道:
>> On 6/1/22 09:39, Min Hu (Connor) wrote:
>>> From: Huisong Li <lihuisong@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(). However, if the new default one has
>>> been added as a non-default MAC address by 
>>> rte_eth_dev_mac_addr_add(), the
>>> the rte_eth_dev_default_mac_addr_set() doesn't remove it from the 
>>> mac_addrs
>>> list. As a result, one MAC address occupies two indexes in the list. 
>>> Like:
>>> add(MAC1)
>>> add(MAC2)
>>> add(MAC3)
>>> add(MAC4)
>>> set_default(MAC3)
>>> default=MAC3, filters=MAC1, MAC2, MAC3, MAC4
>>>
>>> In addition, some PMDs, such as i40e, ice, hns3 and so on, do remove the
>>> old default MAC when set default MAC. If user continues to do
>>> set_default(MAC5), and the mac_addrs list is default=MAC5, 
>>> filters=(MAC1,
>>> MAC2, MAC3, MAC4). At this moment, user can still view MAC3 from the 
>>> list,
>>> but packets with MAC3 aren't actually received by the PMD.
>>
>> IMHO, the main problem is inconsistency which exists right now.
>> rte_eth_dev_mac_addr_add() checks for duplicate MAC addition
>> including the default one (index zero) and extends the entry
>> pool mask (including zero entry case).
>>
>> However, the patch above does not extend zero entry pool mask.
>> So, the result will depend on order which is bad:
>> A. Set default to A, add MAC A with pool 2 => pool mask has 2
>> B. Add MAC A with pool 2, set default to A => pool mask is empty
>>
> I don't know how this MAC pool works in which driver.

Me too

> However, the 'eth_dev_mac_restore' API show that 1) the default MAC has 
> only pool zero
> if set it by the 'mac_addr_add', 2) the default one hasn't pool 
> information if set it
> by 'default_mac_addr_set'.
> 
> Do you mean we should inherit its pool mask in this case?

I simply want to make it consistent

>> Am I missing something in the code?
>> What is the right/intended behaviour?
>>
>>>
>>> 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 <humin29@huawei.com>
>>> ---
>>>   lib/ethdev/rte_ethdev.c | 39 +++++++++++++++++++++++++++++++++++++--
>>>   1 file changed, 37 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
>>> index 46c088dc88..fc9ca8d6fd 100644
>>> --- a/lib/ethdev/rte_ethdev.c
>>> +++ b/lib/ethdev/rte_ethdev.c
>>> @@ -4260,7 +4260,10 @@ rte_eth_dev_mac_addr_remove(uint16_t port_id, 
>>> struct rte_ether_addr *addr)
>>>   int
>>>   rte_eth_dev_default_mac_addr_set(uint16_t port_id, struct 
>>> rte_ether_addr *addr)
>>>   {
>>> +    uint64_t mac_pool_sel_bk = 0;
>>>       struct rte_eth_dev *dev;
>>> +    uint32_t pool;
>>> +    int index;
>>>       int ret;
>>>         RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
>>> @@ -4278,16 +4281,48 @@ rte_eth_dev_default_mac_addr_set(uint16_t 
>>> port_id, struct rte_ether_addr *addr)
>>> RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->mac_addr_set, -ENOTSUP);
>>>   +    /*
>>> +     * 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 */
>>> +        mac_pool_sel_bk = dev->data->mac_pool_sel[index];
>>> +        ret = rte_eth_dev_mac_addr_remove(port_id, addr);
>>> +        if (ret < 0) {
>>> +            RTE_ETHDEV_LOG(ERR,
>>> +            "Delete MAC address from the MAC list of ethdev port 
>>> %u.\n",
>>> +            port_id);
>>> +            return ret;
>>> +        }
>>> +        /* reset pool bitmap */
>>> +        dev->data->mac_pool_sel[index] = 0;
>>> +    }
>>> +
>>>       ret = (*dev->dev_ops->mac_addr_set)(dev, addr);
>>>       if (ret < 0)
>>> -        return ret;
>>> +        goto back;
>>>         /* Update default address in NIC data structure */
>>>       rte_ether_addr_copy(addr, &dev->data->mac_addrs[0]);
>>>         return 0;
>>> -}
>>>   +back:
>>> +    if (index > 0) {
>>> +        pool = 0;
>>> +        do {
>>> +            if (mac_pool_sel_bk & UINT64_C(1))
>>> +                rte_eth_dev_mac_addr_add(port_id, addr, pool);
>>
>> Don't we want to have at least error logs in the case of rollback
>> failure here?
> It doesn't feel necessary. It may trigger the printing of a large number 
> of error logs
> in abnormal scenarios.

Otherwise how will user know that rollback failed and configuration
is inconsistent?

>>
>>> +            mac_pool_sel_bk >>= 1;
>>> +            pool++;
>>> +        } while (mac_pool_sel_bk);
>>
>> Please, compare vs 0 explicitly.
> Ack
>>
>>> +    }
>>> +
>>> +    return ret;
>>> +}
>>>     /*
>>>    * Returns index into MAC address array of addr. Use 
>>> 00:00:00:00:00:00 to find
>>
>> .