Author: Jesús E.
Category: Tutorial
Date: 2020-05-03 03:12
Image: 2020/05/virt-manager.jpg
Lang: en
Save_as: install-a-virtual-machine-manager-on-hyperbola-gnulinux-libre/index.html
URL: install-a-virtual-machine-manager-on-hyperbola-gnulinux-libre/
Slug: instalar-un-gestor-de-maquinas-virtuales-en-hyperbola-gnulinux-libre
Tags: virtual machine, tutorial
Title: Install a virtual machine manager in Hyperbola GNU/Linux-libre

Your host may be Hyperbola GNU/Linux-libre x86_64 architecture, for example,
but with enough memory and processing power you could run
[Trisquel][trisquel]{:target="_blank" rel="noopener noreferrer"} and
[Dragora][dragora]{:target="_blank" rel="noopener noreferrer"}
at the same time, on the same machine.

## What is a virtual machine?

A virtual machine is software that simulates a computer system and can
execute programs as if it were a real computer. This software was
originally defined as "an efficient and isolated duplicate of a
physical machine".

## What programs allow me to run a virtual machine?

In totally free operating systems there is a program
called `qemu` that allows us to virtualize.

[Qemu][qemu]{:target="_blank" rel="noopener noreferrer"}
works through the command line, but there are
also GUIs.

In this guide we explain how to install
[Virtual Machine Manager][vm]{:target="_blank" rel="noopener noreferrer"}
which is very complete when virtualizing operating systems.

## Virtual Machine Manager installation

### Check if your PC supports virtualization

    :::console
    $ LC_ALL=C lscpu | grep Virtualization

or run the command:

    :::console
    $ lsmod | grep kvm

If your computer supports virtualization, you should see the
output as `Virtualization: VT-x` or `Virtualization: AMD-V`,
otherwise your computer is not capable of virtualizing.

### Virtual Machine Manager Installing

    :::console
    # pacman -Sy

    # pacman -S virt-manager qemu vde2 dnsmasq bridge-utils openbsd-netcat libvirt firewalld

    # gpasswd -a <tu-usuario> kvm

    # gpasswd -a <tu-usuario> libvirt

### Check kvm group

    :::console
    # grep -E 'group="kvm"|group="78"' /etc/libvirt/qemu.conf

Check if there is `group="kvm"` or `group="78"`

### Enable kernel modules for virtualization

- kvm_intel module (Intel processors)

        :::console
        # modprobe kvm_intel

- kvm_amd module (AMD processors)

        :::console
        # modprobe kvm_amd

### Verify that the virtual machine is configured correctly

    :::console
    $ virt-host-validate

### Services

Virt-Manager relies on the `libvirtd` and
`firewalld` services to function.

Here we explain how to start these services:

#### Start libvirtd

    :::console
    # rc-service libvirtd start

#### Add libvirtd for default

    :::console
    # rc-update add libvirtd default

#### Start firewalld

    :::console
    # rc-service firewalld start

#### Add firewalld for default

    :::console
    # rc-update add firewalld default

#### Remove Services

If you want to remove the services and start
only when you want, run:

    :::console
    # rc-update del libvirtd default

    # rc-update del firewalld default

### Enable nested virtualization in KVM

Nested virtualization allows you to run a virtual machine (VM)
within another VM while still using host hardware acceleration.

#### Checking if nested virtualization is supported

For Intel processors, check the
`/sys/module/kvm_intel/parameters/nested` file.
For AMD processors, check the
`/sys/module/kvm_amd/parameters/nested`.
If you see `1` or `Y`, nested virtualization is supported;
if you see `0` or `N`, nested virtualization is not supported.

For example:

    :::console
    $ cat /sys/module/kvm_intel/parameters/nested
    Y

#### Enable nested virtualization for Intel processors:

1. Turn off all running virtual machines and reload `kvm_intel` module:

        :::console
        # modprobe -r kvm_intel

2. Activate the nesting function

        :::console
        # modprobe kvm_intel nested=1

3. Nested virtualization is enabled until the host is restarted.
   To enable it permanently, add the following line to
   `/etc/modprobe.d/kvm.conf` file:

        :::console
        # nano -w /etc/modprobe.d/kvm.conf
        ----------------------------------
        options kvm_intel nested=1

#### Enable nested virtualization for AMD processors:

1. Turn off all running virtual machines and reload `kvm_amd` module:

        :::console
        # modprobe -r kvm_amd

2. Activate the nesting function

        :::console
        # modprobe kvm_amd nested=1

3. Nested virtualization is enabled until the host is restarted.
   To enable it permanently, add the following line to
   `/etc/modprobe.d/kvm.conf` file:

        :::console
        # nano -w /etc/modprobe.d/kvm.conf
        ----------------------------------
        options kvm_intel nested=1

### Virtual Machine Manager screenshots

<figure>
    <a href="{filename}/wp-content/uploads/article/images/2020/05/vm-dragora.png">
        <img src="{filename}/wp-content/uploads/article/images/2020/05/vm-dragora.png" alt="Dragora in Virtual Machine Manager">
    </a>
    <figcaption>Screenshot of Dragora GNU/Linux in Virtual Machine Manager</figcaption>
</figure>

<figure>
    <a href="{filename}/wp-content/uploads/article/images/2020/05/vm-trisquel.png">
        <img src="{filename}/wp-content/uploads/article/images/2020/05/vm-trisquel.png" alt="Trisquel in Virtual Machine Manager">
    </a>
    <figcaption>Screenshot of Trisquel GNU/Linux in Virtual Machine Manager</figcaption>
</figure>

### Modules with security issues

The `vhost_net` module has
[CVE-2018-3646][spectre]{:target="_blank" rel="noopener noreferrer"}
security issues which is L1TF and SMT CPU error
with possible data leak.
It's recommended to disable it as follows:

    :::console
    # modprobe -r vhost_net

If you are in Hyperbola GNU/Linux-libre
this module comes disabled.

[dragora]: https://dragora.org
[trisquel]: https://trisquel.info
[qemu]: https://wiki.qemu.org/Main_Page
[spectre]: https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html
[vm]: https://virt-manager.org/
*[GUI]: Graphical user interface
