Re: [dpdk-dev] [dpdk-stable] [PATCH 0/2] support MAC changes when no live changes allowed

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 7/9/2018 6:14 PM, Alejandro Lucero wrote:
> This is a patched to fix a functionality coming with the first public
> release: changing/setting MAC address.
> 
> The original patch assumes all NICs can safely change or set the MAC
> in any case. However, this is not always true. NFP depends on the firmware
> capabilities and this is not always supported. There are other NICs with
> this same limitation, although, as far as I know, not in DPDK. Linux kernel
> has a IFF_LIVE_ADDR_CHANGE flag and two NICs are checking this flag for
> allowing or not live MAC changes.
> 
> The flag proposed in this patch is just the opposite: advertise if live
> change not supported and assuming it is supported other way.
> 
> Although most NICs support rte_eth_dev_default_mac_addr_set and this
> function returns and error when live change is not supported, note that
> this function is invoked during port start but the value returned is not
> checked. It is likely this is good enough for most of the cases, but
> bonding is relying on this start then mac set/change, and a PMD ports is
> not properly configured for being used as an slave port in some bonding
> modes.

Hi Alejandro,

Overall looks good to me, only it can be good to update "rte_eth_dev_start" API
doc to mention about affect of new flag and perhaps update release notes "API
Changes" section to document behavior change of the "rte_eth_dev_start" API
based on flag.

But, the ethdev library patch was late for this release, I suggest considering
the patch for next release, meanwhile it can get more reviews.

Thanks,
ferruh