Improve kvm2 documentation, mention v1.3.1 req

docs/drivers.md

@@ -16,81 +16,66 @@ the host PATH:
 
 ## KVM2 driver
 
-To install the KVM2 driver, first install and configure the prereqs:
+To install the KVM2 driver, first install and configure the prerequisites, namely libvirt 1.3.1 or higher, and qemu-kvm:
 
-* Debian or Ubuntu 18.x:
+* Debian or Ubuntu 18.x: `sudo apt install libvirt-clients libvirt-daemon-system qemu-kvm`
+* Ubuntu 16.x or older: `sudo apt install libvirt-bin libvirt-daemon-system qemu-kvm`
+* Fedora/CentOS/RHEL: `sudo yum install libvirt-daemon-kvm qemu-kvm`
 
-```shell
-sudo apt install libvirt-clients libvirt-daemon-system qemu-kvm
-```
+Check your installed virsh version:
+
+`virsh --version`
+
+If your version of virsh is newer than 1.3.1 (January 2016), you may download our pre-built driver:
 
-* Ubuntu 16.x or older:
 
 ```shell
-sudo apt install libvirt-bin libvirt-daemon-system qemu-kvm
+curl -LO https://storage.googleapis.com/minikube/releases/latest/docker-machine-driver-kvm2 \
+  && sudo install docker-machine-driver-kvm2 /usr/local/bin/
 ```
 
-* Fedora/CentOS/RHEL:
+If your version of virsh is older than 1.3.1 (Januarry 2016), you may build your own driver binary if you have go 1.12+ installed.
 
 ```shell
-sudo yum install libvirt-daemon-kvm qemu-kvm
+$ sudo apt install libvirt-dev
+$ git clone https://github.com/kubernetes/minikube.git
+$ cd minikube
+$ make out/docker-machine-driver-kvm2
+$ sudo install out/docker-machine-driver-kvm2 /usr/local/bin
 ```
 
-Enable,start, and verify the `libvirtd` service has started.
+To finish the kvm installation, start and verify the `libvirtd` service
 
 ```shell
 sudo systemctl enable libvirtd.service
 sudo systemctl start libvirtd.service
 sudo systemctl status libvirtd.service
 ```
 
-Then you will need to add yourself to `libvirt` group (older distributions may use `libvirtd` instead)
+Add your user to `libvirt` group (older distributions may use `libvirtd` instead)
 
 ```shell
 sudo usermod -a -G libvirt $(whoami)
 ```
 
-Then to join the group with your current user session:
+Join the `libvirt` group with your current shell session:
 
 ```shell
 newgrp libvirt
 ```
 
-Now install the driver:
-
-```shell
-curl -LO https://storage.googleapis.com/minikube/releases/latest/docker-machine-driver-kvm2 \
-  && sudo install docker-machine-driver-kvm2 /usr/local/bin/
-```
-
-NOTE: Ubuntu users on a release older than 18.04, or anyone experiencing [#3206: Error creating new host: dial tcp: missing address.](https://github.com/kubernetes/minikube/issues/3206) you will need to build your own driver until [#3689](https://github.com/kubernetes/minikube/issues/3689) is resolved. Building this binary will require [Go v1.12](https://golang.org/dl/) or newer to be installed.
-
-```shell
-$ sudo apt install libvirt-dev
-$ git clone https://github.com/kubernetes/minikube.git
-$ cd minikube
-$ make out/docker-machine-driver-kvm2
-$ sudo install out/docker-machine-driver-kvm2 /usr/local/bin
-```
-
 To use the kvm2 driver:
 
 ```shell
 minikube start --vm-driver kvm2
 ```
 
-or, to use kvm2 as a default driver:
+or, to use kvm2 as a default driver for `minikube start`:
 
 ```shell
 minikube config set vm-driver kvm2
 ```
 
-and run minikube as usual:
-
-```shell
-minikube start
-```
-
 ## Hyperkit driver
 
 Install the [hyperkit](http://github.com/moby/hyperkit) VM manager using [brew](https://brew.sh):