Re: [PATCH V5] ethdev: fix one address occupies two indexes in MAC addrs

[Thomas Monjalon <thomas@monjalon.net>]

Hi,

You missed some questions and comments below.

19/01/2023 10:57, lihuisong (C):
> 在 2023/1/18 16:26, Thomas Monjalon 写道:
> > 20/10/2022 11:31, Huisong Li:
> >> The dev->data->mac_addrs[0] will be changed to a new MAC address when
> >> applications modify the default MAC address by .mac_addr_set(). However,
> >> if the new default one has been added as a non-default MAC address by
> >> .mac_addr_add(), the .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
> > I agree it would be simpler to ensure that the addresses are uniques.
> >
> >> 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 see MAC3 from the list,
> >> but packets with MAC3 aren't actually received by the PMD.
> > If MAC3 is not removed with rte_eth_dev_mac_addr_remove() by the app,
> > MAC3 packets should be received.
> > The MAC address should not be removed by the PMD.
> >
> >> So this patch adds a remove operation in set default MAC API documents
> >> this behavior.
> > Let's be clear here: only the new default address is removed from the rest of the list.
> >
> >> Fixes: 854d8ad4ef68 ("ethdev: add default mac address modifier")
> >> Cc: stable@dpdk.org
> >> --- a/lib/ethdev/ethdev_driver.h
> >> +++ b/lib/ethdev/ethdev_driver.h
> >> @@ -116,7 +116,12 @@ struct rte_eth_dev_data {
> >>   
> >>   	uint64_t rx_mbuf_alloc_failed; /**< Rx ring mbuf allocation failures */
> >>   
> >> -	/** Device Ethernet link address. @see rte_eth_dev_release_port() */
> >> +	/**
> >> +	 * Device Ethernet link address. The index zero of the array is as the
> > It should be "addresses" as there can be multiple.
> >
> > What means "as" above?
> > Can we say the first entry (index zero) is the default address?
> >
> >> +	 * index of the default address, and other indexes can't be the same
> > You can split the sentence in 2 instead of ", and".
> > indexes -> entries
> > can't -> cannot
> >
> >> +	 * as the address corresponding to index 0.
> > simpler: as the default address.
> >
> >> +	 * @see rte_eth_dev_release_port()
> > Why referencing this function here?
> >
> >> +	 */
> >> --- a/lib/ethdev/rte_ethdev.c
> >> +++ b/lib/ethdev/rte_ethdev.c
> >> @@ -4498,7 +4498,10 @@ 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);
> >> @@ -4517,16 +4520,50 @@ rte_eth_dev_default_mac_addr_set(uint16_t port_id, struct rte_ether_addr *addr)
> >>   	if (*dev->dev_ops->mac_addr_set == NULL)
> >>   		return -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[].
> >> +	 */
> > Make is simpler:
> > "Keep address unique in dev->data->mac_addrs[]."
> Ack
> >
> >> +	index = eth_dev_get_mac_addr_index(port_id, addr);
> >> +	if (index > 0) {
> >> +		/* Remove address in dev 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);
> > It is not clear with this log that it failed.
> Adjust as follows?
> "Delete old address entry from the MAC list of ethdev port %u.\n"
> >
> >> +			return ret;
> >> +		}
> >> +		/* Reset pool bitmap */
> >> +		dev->data->mac_pool_sel[index] = 0;
> > mac_pool_sel[index] is already reset in rte_eth_dev_mac_addr_remove().
> Yes, this can be deleted.
> >
> >> +	}
> >>   	ret = (*dev->dev_ops->mac_addr_set)(dev, addr);
> >>   	if (ret < 0)
> >> -		return ret;
> >> +		goto out;
> >>   
> >>   	/* Update default address in NIC data structure */
> >>   	rte_ether_addr_copy(addr, &dev->data->mac_addrs[0]);
> >>   
> >>   	return 0;
> >> -}
> >>   
> >> +out:
> >> +	if (index > 0) {
> >> +		pool = 0;
> >> +		do {
> >> +			if (mac_pool_sel_bk & UINT64_C(1)) {
> >> +				if (rte_eth_dev_mac_addr_add(port_id, addr,
> >> +							     pool) != 0)
> >> +					RTE_ETHDEV_LOG(ERR, "failed to restore MAC pool id(%u) in port %u.\n",
> >> +						       pool, port_id);
> >> +			}
> >> +			mac_pool_sel_bk >>= 1;
> >> +			pool++;
> >> +		} while (mac_pool_sel_bk != 0);
> >> +	}
> >> +
> >> +	return ret;
> >> +}
> > Can we avoid this rollback by removing the address after mac_addr_set() succeed?
> No, the new default address will be removed if we do that.
> we need to remove it first if the new default address has been added as a
> non-default MAC address to the MAC list.

OK yes.