On Tue, 20 Oct 2020 16:18:04 -0500 Lijun Pan wrote: > > On Oct 19, 2020, at 7:11 PM, Jakub Kicinski <k...@kernel.org> wrote: > > > > On Thu, 15 Oct 2020 23:57:15 -0500 Lijun Pan wrote: > >> After mac address change request completes successfully, the new mac > >> address need to be saved to adapter->mac_addr as well as > >> netdev->dev_addr. Otherwise, adapter->mac_addr still holds old > >> data. > > > > Do you observe this in practice? Can you show us which path in > > particular you see this happen on? > > > > AFAICS ibmvnic_set_mac() copies the new MAC addr into adapter->mac_addr > > before making a request. > > > > If anything is wrong here is that it does so regardless if MAC addr > > is valid. > > Yes, I ran some internal test to check the mac address in adapter->mac_addr, > and > it is the old data. If you run ifconfig command to change mac addr, the > netdev->dev_addr > is changed afterwards, and if you run ifocnfig again, it will show the new > mac addr. However, > since we did not check adapter->mac_addr in this use case, this bug was not > exposed. > > This vnic driver is little bit different than other physical NIC driver. All > the control paths > are negotaited with VIOS server, and data paths are through DMA mapping. > > __ibmvnic_set_mac copies the new mac addr to crq by > ether_addr_copy(&crq.change_mac_addr.mac_addr[0], dev_addr); > and then send the change request by > rc = ibmvnic_send_crq(adapter, &crq); > Now adapter->mac_addr still has the old data. > > When the request is handled by VIOS server, an interrupt is triggered, and > handle_change_mac_rsp is called. > Now it is time to copy the new mac to netdev->dev_addr, and adatper->mac_addr. > ether_addr_copy(netdev->dev_addr, > &crq->change_mac_addr_rsp.mac_addr[0]); > It missed the copy for adapter->mac_addr, which is what I add in this patch. > + ether_addr_copy(adapter->mac_addr, > + &crq->change_mac_addr_rsp.mac_addr[0]);
Please read my reply carefully. What's the call path that leads to the address being wrong? If you set the address via ifconfig it will call ibmvnic_set_mac() of the driver. ibmvnic_set_mac() does the copy. But it doesn't validate the address, which it should.
