net: use core MTU range checking in virt drivers

hyperv_net:
- set min/max_mtu, per Haiyang, after rndis_filter_device_add

virtio_net:
- set min/max_mtu
- remove virtnet_change_mtu

vmxnet3:
- set min/max_mtu

xen-netback:
- min_mtu = 0, max_mtu = 65517

xen-netfront:
- min_mtu = 0, max_mtu = 65535

unisys/visor:
- clean up defines a little to not clash with network core or add
  redundat definitions

CC: netdev@vger.kernel.org
CC: virtualization@lists.linux-foundation.org
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: "Michael S. Tsirkin" <mst@redhat.com>
CC: Shrikrishna Khare <skhare@vmware.com>
CC: "VMware, Inc." <pv-drivers@vmware.com>
CC: Wei Liu <wei.liu2@citrix.com>
CC: Paul Durrant <paul.durrant@citrix.com>
CC: David Kershner <david.kershner@unisys.com>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 9 insertions, 9 deletions

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index f4fbcb5..3958ada 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -606,8 +606,8 @@ struct nvsp_message {
 } __packed;
 
 
-#define NETVSC_MTU 65536
-#define NETVSC_MTU_MIN 68
+#define NETVSC_MTU 65535
+#define NETVSC_MTU_MIN ETH_MIN_MTU
 
 #define NETVSC_RECEIVE_BUFFER_SIZE		(1024*1024*16)	/* 16MB */
 #define NETVSC_RECEIVE_BUFFER_SIZE_LEGACY	(1024*1024*15)  /* 15MB */
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index f0919bd..3b28cf1 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -872,19 +872,12 @@ static int netvsc_change_mtu(struct net_device *ndev, int mtu)
 	struct netvsc_device *nvdev = ndevctx->nvdev;
 	struct hv_device *hdev = ndevctx->device_ctx;
 	struct netvsc_device_info device_info;
-	int limit = ETH_DATA_LEN;
 	u32 num_chn;
 	int ret = 0;
 
 	if (ndevctx->start_remove || !nvdev || nvdev->destroy)
 		return -ENODEV;
 
-	if (nvdev->nvsp_version >= NVSP_PROTOCOL_VERSION_2)
-		limit = NETVSC_MTU - ETH_HLEN;
-
-	if (mtu < NETVSC_MTU_MIN || mtu > limit)
-		return -EINVAL;
-
 	ret = netvsc_close(ndev);
 	if (ret)
 		goto out;
@@ -1402,6 +1395,13 @@ static int netvsc_probe(struct hv_device *dev,
 	netif_set_real_num_tx_queues(net, nvdev->num_chn);
 	netif_set_real_num_rx_queues(net, nvdev->num_chn);
 
+	/* MTU range: 68 - 1500 or 65521 */
+	net->min_mtu = NETVSC_MTU_MIN;
+	if (nvdev->nvsp_version >= NVSP_PROTOCOL_VERSION_2)
+		net->max_mtu = NETVSC_MTU - ETH_HLEN;
+	else
+		net->max_mtu = ETH_DATA_LEN;
+
 	ret = register_netdev(net);
 	if (ret != 0) {
 		pr_err("Unable to register netdev.\n");