Re: [dpdk-dev] [PATCH 2/2] net/bonding: fix MAC address when one port resets

[Chas Williams <3chas3@gmail.com>]

The behavior is probably going to be inconsistent. Only one of the calls
to mac_address_slaves_update() is checked for failure. The two calls
are in bond_ethdev_lsc_event_callback()

                 if (internals->active_slave_count < 1) {
                         mac_address_slaves_update(bonded_eth_dev);

and in bond_ethdev_start():

         /* Update all slave devices MACs*/
         if (mac_address_slaves_update(eth_dev) != 0)
                 goto out_err;

So if the bond device is running, you safely fail to the backup device.
But if you stop and start the bond device, it will then fail to start?

What devices are you bonding together that aren't able to support
changing their MAC addresses reliably? ixgbe VF devices by any chance?
One solution is to always assume success or ignore the error from devices
that you know are not an issue. I agree that we shouldn't early exit
from mac_address_slaves_update(). I am not sure how to handle the error.

We probably shouldn't allow you to bond devices that don't support setting
MAC address. I don't think this check exists currently. That's possibly
one reason for this check.

On 2/25/20 4:29 AM, Wei Hu (Xavier) wrote:
 > From: "Wei Hu (Xavier)" <xavier.huwei@huawei.com>
 >
 > Currently, based on a active-backup bond device, in the following 2 
cases:
 > 1) The primary port resets. The link status of the primary port changes
 >     from up to down.
 > 2) When switching the active port, one slave port resets at the same 
time.
 > one slave port changes to the primary port, but the new primary 
port's MAC
 > address probably cannot change to the bond device's MAC address. And we
 > can't continue receive packets whose destination MAC addresses are 
the same
 > as the bond devices's MAC address.
 >
 > The current bonding PMD driver call mac_address_slaves_update function to
 > modify the MAC address of all slaves devices. In 
mac_address_slaves_update
 > function, the rte_eth_dev_default_mac_addr_set API function is called to
 > set the MAC address of the slave devices in turn in the for loop 
statement.
 >
 > When one port reset, calling rte_eth_dev_default_mac_addr_set API fails
 > because the firmware will not respond to the commands from the driver,
 > and exit the loop, so other slave devices cannot continue to update the
 > MAC address.
 >
 > This patch fixes the issue by avoid exiting the loop when calling
 > rte_eth_dev_default_mac_addr_set fails.
 >
 > Fixes: 2efb58cbab6e ("bond: new link bonding library")
 > Cc: stable@dpdk.org
 >
 > Signed-off-by: Hongbo Zheng <zhenghongbo3@huawei.com>
 > Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
 > Signed-off-by: Chunsong Feng <fengchunsong@huawei.com>
 > Signed-off-by: Xuan Li <lixuan47@hisilicon.com>
 > ---
 >   drivers/net/bonding/rte_eth_bond_pmd.c | 8 ++++++--
 >   1 file changed, 6 insertions(+), 2 deletions(-)
 >
 > diff --git a/drivers/net/bonding/rte_eth_bond_pmd.c 
b/drivers/net/bonding/rte_eth_bond_pmd.c
 > index ddae3518c..ba3f342e7 100644
 > --- a/drivers/net/bonding/rte_eth_bond_pmd.c
 > +++ b/drivers/net/bonding/rte_eth_bond_pmd.c
 > @@ -1502,6 +1502,7 @@ int
 >   mac_address_slaves_update(struct rte_eth_dev *bonded_eth_dev)
 >   {
 >   	struct bond_dev_private *internals = 
bonded_eth_dev->data->dev_private;
 > +	bool setted;
 >   	int i;
 >
 >   	/* Update slave devices MAC addresses */
 > @@ -1529,6 +1530,7 @@ mac_address_slaves_update(struct rte_eth_dev 
*bonded_eth_dev)
 >   	case BONDING_MODE_TLB:
 >   	case BONDING_MODE_ALB:
 >   	default:
 > +		setted = true;
 >   		for (i = 0; i < internals->slave_count; i++) {
 >   			if (internals->slaves[i].port_id ==
 >   					internals->current_primary_port) {
 > @@ -1537,7 +1539,7 @@ mac_address_slaves_update(struct rte_eth_dev 
*bonded_eth_dev)
 >   						bonded_eth_dev->data->mac_addrs)) {
 >   					RTE_BOND_LOG(ERR, "Failed to update port Id %d MAC address",
 >   							internals->current_primary_port);
 > -					return -1;
 > +					setted = false;
 >   				}
 >   			} else {
 >   				if (rte_eth_dev_default_mac_addr_set(
 > @@ -1545,10 +1547,12 @@ mac_address_slaves_update(struct rte_eth_dev 
*bonded_eth_dev)
 >   						&internals->slaves[i].persisted_mac_addr)) {
 >   					RTE_BOND_LOG(ERR, "Failed to update port Id %d MAC address",
 >   							internals->slaves[i].port_id);
 > -					return -1;
 > +					setted = false;
 >   				}
 >   			}
 >   		}
 > +		if (!setted)
 > +			return -1;
 >   	}
 >
 >   	return 0;
 >