containers-and-vms/index,libvirt: Add sections.

Also move `lxc` into `containers-and-vms`.

Author: flexibeast

src/SUMMARY.md

@@ -60,7 +60,9 @@
    - [TeX Live](./config/texlive.md)
    - [External Applications](./config/external-applications.md)
    - [Printing](./config/print/index.md)
-   - [LXC](./config/lxc.md)
+   - [Containers and Virtual Machines](./config/containers-and-vms/index.md)
+      - [libvirt](./config/containers-and-vms/libvirt.md)
+      - [LXC](./config/containers-and-vms/lxc.md)
 - [XBPS Package Manager](./xbps/index.md)
    - [Advanced Usage](./xbps/advanced-usage.md)
    - [Repositories](./xbps/repositories/index.md)

src/config/containers-and-vms/index.md

@@ -0,0 +1,9 @@
+# Containers and Virtual Machines
+
+This section describes how to set up some of the container and virtual machine
+software available on Void.
+
+## Section Contents
+
+- [libvirt](./libvirt.md)
+- [LXC](./lxc.md)

src/config/containers-and-vms/libvirt.md

@@ -0,0 +1,32 @@
+# libvirt
+
+[libvirt](https://libvirt.org/) is an API and daemon for managing platform
+virtualization, supporting virtualization technologies such as LXC, KVM, QEMU,
+Bhyve, Xen, VMWare, and Hyper-V.
+
+To use libvirt, install the `libvirt` package and
+[enable](../services/index.md#enabling-services) the `libvirtd`, `virtlockd` and
+`virtlogd` services. The `libvirtd` daemon can be reconfigured at runtime via
+[virt-admin(1)](https://man.voidlinux.org/virt-admin.1).
+
+The `libvirt` package provides the [virsh(1)](https://man.voidlinux.org/virsh.1)
+interface to libvirtd. `virsh` is an interactive shell and batch-scriptable tool
+for performing management tasks, including creating, configuring and running
+virtual machines, and managing networks and storage. Note that `virsh` usually
+needs to be run as root, as described in the `virsh` man page:
+
+> Most virsh commands require root privileges to run due to the communications
+> channels used to talk to the hypervisor. Running as non root will return an
+> error.
+
+However, if you have the `polkit` and `dbus` packages installed and you enable
+the `dbus` service, `libvirtd` will grant necessary privileges to any user added
+to the `libvirt` group.
+
+An alternative to `virsh` is provided by the `virt-manager` and
+`virt-manager-tools` packages.
+
+For general information on libvirt, refer to [the libvirt
+wiki](https://wiki.libvirt.org/page/Main_Page) and [the wiki's
+FAQ](https://wiki.libvirt.org/page/FAQ). For an introduction to libvirt usage,
+refer to [the "VM lifecycle" page](https://wiki.libvirt.org/page/VM_lifecycle).

src/config/lxc.md src/config/containers-and-vms/lxc.mdsrc/config/lxc.md renamed to src/config/containers-and-vms/lxc.md

@@ -119,7 +119,7 @@ wrong map is possible, but inconvenient.
 LXD provides an alternative interface to LXC's `lxc-*` utilities. However, it
 does not require the configuration described in [the previous section](#lxc).
 
-Install the `lxd` package, and [enable](./services/index.md#enabling-services)
+Install the `lxd` package, and [enable](../services/index.md#enabling-services)
 the `lxd` service.
 
 LXD users must belong to the `lxd` group.