i40evf: Change a VF mac without reloading the VF driver

Add possibility to change a VF mac address from host side
without reloading the VF driver on the guest side. Without
this patch it is not possible to change the VF mac because
executing i40evf_virtchnl_completion function with
VIRTCHNL_OP_GET_VF_RESOURCES opcode resets the VF mac
address to previous value.

Signed-off-by: Paweł Jabłoński <pawel.jablonski@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c

@@ -2458,7 +2458,7 @@ static inline int i40e_check_vf_permission(struct i40e_vf *vf,
 		    !is_multicast_ether_addr(addr) && vf->pf_set_mac &&
 		    !ether_addr_equal(addr, vf->default_lan_addr.addr)) {
 			dev_err(&pf->pdev->dev,
-				"VF attempting to override administratively set MAC address, reload the VF driver to resume normal operation\n");
+				"VF attempting to override administratively set MAC address, bring down and up the VF interface to resume normal operation\n");
 			return -EPERM;
 		}
 	}
@@ -3873,9 +3873,11 @@ int i40e_ndo_set_vf_mac(struct net_device *netdev, int vf_id, u8 *mac)
 			 mac, vf_id);
 	}
 
-	/* Force the VF driver stop so it has to reload with new MAC address */
+	/* Force the VF interface down so it has to bring up with new MAC
+	 * address
+	 */
 	i40e_vc_disable_vf(vf);
-	dev_info(&pf->pdev->dev, "Reload the VF driver to make this change effective.\n");
+	dev_info(&pf->pdev->dev, "Bring down and up the VF interface to make this change effective.\n");
 
 error_param:
 	return ret;

drivers/net/ethernet/intel/i40evf/i40evf_virtchnl.c

@@ -1330,8 +1330,15 @@ void i40evf_virtchnl_completion(struct i40evf_adapter *adapter,
 			  sizeof(struct virtchnl_vsi_resource);
 		memcpy(adapter->vf_res, msg, min(msglen, len));
 		i40e_vf_parse_hw_config(&adapter->hw, adapter->vf_res);
-		/* restore current mac address */
-		ether_addr_copy(adapter->hw.mac.addr, netdev->dev_addr);
+		if (is_zero_ether_addr(adapter->hw.mac.addr)) {
+			/* restore current mac address */
+			ether_addr_copy(adapter->hw.mac.addr, netdev->dev_addr);
+		} else {
+			/* refresh current mac address if changed */
+			ether_addr_copy(netdev->dev_addr, adapter->hw.mac.addr);
+			ether_addr_copy(netdev->perm_addr,
+					adapter->hw.mac.addr);
+		}
 		i40evf_process_config(adapter);
 		}
 		break;