-----Original Message-----From: Richardson, Bruce <bruce.richardson@intel.com> Sent: Thursday, February 16, 2023 9:05 AM To: Ferruh Yigit <ferruh.yigit@amd.com>; techboard@dpdk.org Cc: Huisong Li <lihuisong@huawei.com>; Chengwen Feng <fengchengwen@huawei.com> Subject: RE: MAC address set requires decision Alternative suggestions: 1. Don't allow "set" of mac address to value already in the list. The user must delete the entry manually first before adding it. Similarly, "add" fails if no default mac address is set. This ensures consistency by enforcing strict separation between the default mac address and the extra mac addresses. You can't have extra addresses without a default, and you can't have duplicates. 2. Always enforce overlap between the two lists - once default mac address is set (automatically adding it to the mac addresses list), you can only replace the default mac address by using an already-added one to the list. In this case, the default address is only really an index into the address list, and no deletion ever occurs. All the solutions below seem rather mixed to me, I'd rather see either strict overlap, or strict non-overlap. Both these cases make it that you need more calls to do certain tasks, e.g. with #2 to just replace mac address, you need to add, set, then delete, but we can always add new, clearly named APIs, to do these compound ops. On the plus side, with #2 we could make things doubly clear by changing the parameter type of "set" to be an index, rather than explicit mac, to make it clear what is happening, that you are choosing a default mac from a list of pre-configured options. Regards, /Bruce
Both of the above option seems good. The option #1 above is
safe, where
you are making the mac address set as independent of mac
filtering. Also making
sure that mac filter are not messed up. However, the application
needs to add error handling now to delete and set.
In the option #2,
I assume, it will
provide full
backward compatibility i.e. the ethernet library can take care
of the logic and
application need not to implement anything extra ? If that is
the case, it seems to be best.
Regards
Hemant
-----Original Message----- From: Ferruh Yigit <ferruh.yigit@amd.com> Sent: Thursday, February 16, 2023 2:44 PM To: techboard@dpdk.org Cc: Huisong Li <lihuisong@huawei.com>; Chengwen Feng <fengchengwen@huawei.com> Subject: MAC address set requires decision Hi Board, We need a decision on how MAC address set works in DPDK, is it possible to vote offline so we can proceed with the patch for this release? Can you please select one of: a) Keep current implementation b) Proposal 1 c) Proposal 2 Details below, @Huisong feel free to add/correct if needed. Background: DPDK supports multiple MAC address for MAC filtering. MAC addresses are kept in a list, and index 0 is default MAC address. `rte_eth_dev_default_mac_addr_set()` -> sets default MAC [ set() ] `rte_eth_dev_mac_addr_add()` -> adds MAC to list, if no default MAC set this adds to index 0 [ add() ] `rte_eth_dev_mac_addr_remove()` -> remove MAC from list [ del() ] Problem: When a MAC address is already in the list, if set() called, what will be the behavior? Like: add(MAC1) => MAC1 add(MAC2) => MAC1, MAC2 add(MAC3) => MAC1, MAC2, MAC3 set(MAC2) => ??? Current code behavior: add(MAC1) => MAC1 add(MAC2) => MAC1, MAC2 add(MAC3) => MAC1, MAC2, MAC3 set(MAC2) => MAC2, MAC2, MAC3 Problem with current behavior: - A MAC address is duplicated in list (MAC2), and this leads different implementation for different PMDs. Some removes MAC2 filter some not. - Can't delete duplicate, because del() tries to delete first MAC it finds and since it first finds default MAC address, fails to delete. (We can fix del() if desicion to keep this implementation.) Proposal 1 (in the patchwork): https://patches.dpdk.org/project/dpdk/patch/20230202123625.14975-1- lihuisong@huawei.com/ set(MAC) deletes MAC if it is in the list: add(MAC1) => MAC1 add(MAC2) => MAC1, MAC2 add(MAC3) => MAC1, MAC2, MAC3 set(MAC2) => MAC2, MAC3 set(MAC3) => MAC3 Disagreement on this proposal: - It causes implicit delete of MAC addresses in the list, so MAC list may shrink with multiple set() calls, this may be confusing Proposal 2 (suggested alternative): set(MAC) { if only_default_mac_exist replace_default_mac if MAC exists in list swap MAC and list[0] else replace_default_mac } Intention here is to prevent implicit delete, swap is just a way to keep MAC address in the list, like: add(MAC1) => MAC1 add(MAC2) => MAC1, MAC2 add(MAC3) => MAC1, MAC2, MAC3 set(MAC2) => MAC2, MAC1, MAC3 set(MAC3) => MAC3, MAC1, MAC2 Disagreement on this proposal: - It is not clear user expects to keep swapped MAC address. Thanks, Ferruh