hv_netvsc: Make netvsc/VF binding check both MAC and serial number

Currently the netvsc/VF binding logic only checks the PCI serial number.

The Microsoft Azure Network Adapter (MANA) supports multiple net_device
interfaces (each such interface is called a "vPort", and has its unique
MAC address) which are backed by the same VF PCI device, so the binding
logic should check both the MAC address and the PCI serial number.

The change should not break any other existing VF drivers, because
Hyper-V NIC SR-IOV implementation requires the netvsc network
interface and the VF network interface have the same MAC address.
Co-developed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Co-developed-by: Shachar Raindel <shacharr@microsoft.com>
Signed-off-by: Shachar Raindel <shacharr@microsoft.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/hyperv/netvsc_drv.c

@@ -2297,6 +2297,7 @@ static struct net_device *get_netvsc_byslot(const struct net_device *vf_netdev)
 {
 	struct device *parent = vf_netdev->dev.parent;
 	struct net_device_context *ndev_ctx;
+	struct net_device *ndev;
 	struct pci_dev *pdev;
 	u32 serial;
 
@@ -2319,8 +2320,17 @@ static struct net_device *get_netvsc_byslot(const struct net_device *vf_netdev)
 		if (!ndev_ctx->vf_alloc)
 			continue;
 
-		if (ndev_ctx->vf_serial == serial)
-			return hv_get_drvdata(ndev_ctx->device_ctx);
+		if (ndev_ctx->vf_serial != serial)
+			continue;
+
+		ndev = hv_get_drvdata(ndev_ctx->device_ctx);
+		if (ndev->addr_len != vf_netdev->addr_len ||
+		    memcmp(ndev->perm_addr, vf_netdev->perm_addr,
+			   ndev->addr_len) != 0)
+			continue;
+
+		return ndev;
+
 	}
 
 	netdev_notice(vf_netdev,