net: xen: use eth_hw_addr_set()

Commit 406f42fa ("net-next: When a bond have a massive amount
of VLANs...") introduced a rbtree for faster Ethernet address look
up. To maintain netdev->dev_addr in this tree we need to make all
the writes to it got through appropriate helpers.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/xen-netback/interface.c

@@ -494,6 +494,9 @@ static const struct net_device_ops xenvif_netdev_ops = {
 struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
 			    unsigned int handle)
 {
+	static const u8 dummy_addr[ETH_ALEN] = {
+		0xfe, 0xff, 0xff, 0xff, 0xff, 0xff,
+	};
 	int err;
 	struct net_device *dev;
 	struct xenvif *vif;
@@ -551,8 +554,7 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
 	 * stolen by an Ethernet bridge for STP purposes.
 	 * (FE:FF:FF:FF:FF:FF)
 	 */
-	eth_broadcast_addr(dev->dev_addr);
-	dev->dev_addr[0] &= ~0x01;
+	eth_hw_addr_set(dev, dummy_addr);
 
 	netif_carrier_off(dev);
 

drivers/net/xen-netfront.c

@@ -2157,6 +2157,7 @@ static int talk_to_netback(struct xenbus_device *dev,
 	unsigned int max_queues = 0;
 	struct netfront_queue *queue = NULL;
 	unsigned int num_queues = 1;
+	u8 addr[ETH_ALEN];
 
 	info->netdev->irq = 0;
 
@@ -2170,11 +2171,12 @@ static int talk_to_netback(struct xenbus_device *dev,
 					"feature-split-event-channels", 0);
 
 	/* Read mac addr. */
-	err = xen_net_read_mac(dev, info->netdev->dev_addr);
+	err = xen_net_read_mac(dev, addr);
 	if (err) {
 		xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
 		goto out_unlocked;
 	}
+	eth_hw_addr_set(info->netdev, addr);
 
 	info->netback_has_xdp_headroom = xenbus_read_unsigned(info->xbdev->otherend,
 							      "feature-xdp-headroom", 0);