@@ -589,6 +589,7 @@ struct nvsp_message {
#define NETVSC_MTU 65536
+#define NETVSC_MTU_MIN 68
#define NETVSC_RECEIVE_BUFFER_SIZE (1024*1024*16) /* 16MB */
#define NETVSC_RECEIVE_BUFFER_SIZE_LEGACY (1024*1024*15) /* 15MB */
@@ -714,8 +714,7 @@ static int netvsc_change_mtu(struct net_device *ndev, int mtu)
if (nvdev->nvsp_version >= NVSP_PROTOCOL_VERSION_2)
limit = NETVSC_MTU - ETH_HLEN;
- /* Hyper-V hosts don't support MTU < ETH_DATA_LEN (1500) */
- if (mtu < ETH_DATA_LEN || mtu > limit)
+ if (mtu < NETVSC_MTU_MIN || mtu > limit)
return -EINVAL;
nvdev->start_remove = true;
@@ -1046,7 +1046,7 @@ int rndis_filter_device_add(struct hv_device *dev,
ret = rndis_filter_query_device(rndis_device,
RNDIS_OID_GEN_MAXIMUM_FRAME_SIZE,
&mtu, &size);
- if (ret == 0 && size == sizeof(u32))
+ if (ret == 0 && size == sizeof(u32) && mtu < net_device->ndev->mtu)
net_device->ndev->mtu = mtu;
/* Get the mac address */