VMXNET3_TXD_NEEDED
int count = VMXNET3_TXD_NEEDED(skb_headlen(skb)) + 1;
count += VMXNET3_TXD_NEEDED(skb_frag_size(frag));
count = VMXNET3_TXD_NEEDED(skb_headlen(skb)) + 1;
count = VMXNET3_TXD_NEEDED(skb_headlen(skb)) + 1;