VirtualBox driver uses virtio network driver

Kernel has CONFIG_VIRTIO_NET=y.

Read more at https://www.virtualbox.org/manual/ch06.html

pkg/minikube/cluster/cluster.go

@@ -46,6 +46,10 @@ import (
 	"k8s.io/minikube/pkg/util"
 )
 
+const (
+	defaultVirtualboxNicType = "virtio"
+)
+
 //This init function is used to set the logtostderr variable to false so that INFO level log info does not clutter the CLI
 //INFO lvl logging is displayed due to the kubernetes api calling flag.Set("logtostderr", "true") in its init()
 //see: https://github.com/kubernetes/kubernetes/blob/master/pkg/kubectl/util/logs/logs.go#L32-L34
@@ -183,6 +187,8 @@ func createVirtualboxHost(config MachineConfig) drivers.Driver {
 	d.DiskSize = int(config.DiskSize)
 	d.HostOnlyCIDR = config.HostOnlyCIDR
 	d.NoShare = config.DisableDriverMounts
+	d.NatNicType = defaultVirtualboxNicType
+	d.HostOnlyNicType = defaultVirtualboxNicType
 	return d
 }