man/systemd-detect-virt.xml

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   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
   4 <!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
   5
   6 <refentry id="systemd-detect-virt"
   7           xmlns:xi="http://www.w3.org/2001/XInclude">
   8
   9   <refentryinfo>
  10     <title>systemd-detect-virt</title>
  11     <productname>systemd</productname>
  12   </refentryinfo>
  13
  14   <refmeta>
  15     <refentrytitle>systemd-detect-virt</refentrytitle>
  16     <manvolnum>1</manvolnum>
  17   </refmeta>
  18
  19   <refnamediv>
  20     <refname>systemd-detect-virt</refname>
  21     <refpurpose>Detect execution in a virtualized environment</refpurpose>
  22   </refnamediv>
  23
  24   <refsynopsisdiv>
  25     <cmdsynopsis>
  26       <command>systemd-detect-virt</command>
  27       <arg choice="opt" rep="repeat">OPTIONS</arg>
  28     </cmdsynopsis>
  29   </refsynopsisdiv>
  30
  31   <refsect1>
  32     <title>Description</title>
  33
  34     <para><command>systemd-detect-virt</command> detects execution in
  35     a virtualized environment. It identifies the virtualization
  36     technology and can distinguish full machine virtualization from
  37     container virtualization. <filename>systemd-detect-virt</filename>
  38     exits with a return value of 0 (success) if a virtualization
  39     technology is detected, and non-zero (error) otherwise. By default,
  40     any type of virtualization is detected, and the options
  41     <option>--container</option> and <option>--vm</option> can be used
  42     to limit what types of virtualization are detected.</para>
  43
  44     <para>When executed without <option>--quiet</option> will print a
  45     short identifier for the detected virtualization technology. The
  46     following technologies are currently identified:</para>
  47
  48     <table>
  49       <title>Known virtualization technologies (both
  50       VM, i.e. full hardware virtualization,
  51       and container, i.e. shared kernel virtualization)</title>
  52       <tgroup cols='3' align='left' colsep='1' rowsep='1'>
  53         <colspec colname="type" />
  54         <colspec colname="id" />
  55         <colspec colname="product" />
  56         <thead>
  57           <row>
  58             <entry>Type</entry>
  59             <entry>ID</entry>
  60             <entry>Product</entry>
  61           </row>
  62         </thead>
  63         <tbody>
  64           <row>
  65             <entry valign="top" morerows="16">VM</entry>
  66             <entry><varname>qemu</varname></entry>
  67             <entry>QEMU software virtualization, without KVM</entry>
  68           </row>
  69
  70           <row>
  71             <entry><varname>kvm</varname></entry>
  72             <entry>Linux KVM kernel virtual machine, in combination with QEMU. Not used for other virtualizers using the KVM interfaces, such as Oracle VirtualBox or Amazon EC2 Nitro, see below.</entry>
  73           </row>
  74
  75           <row>
  76             <entry><varname>amazon</varname></entry>
  77             <entry>Amazon EC2 Nitro using Linux KVM</entry>
  78           </row>
  79
  80           <row>
  81             <entry><varname>zvm</varname></entry>
  82             <entry>s390 z/VM</entry>
  83           </row>
  84
  85           <row>
  86             <entry><varname>vmware</varname></entry>
  87             <entry>VMware Workstation or Server, and related products</entry>
  88           </row>
  89
  90           <row>
  91             <entry><varname>microsoft</varname></entry>
  92             <entry>Hyper-V, also known as Viridian or Windows Server Virtualization</entry>
  93           </row>
  94
  95           <row>
  96             <entry><varname>oracle</varname></entry>
  97             <entry>Oracle VM VirtualBox (historically marketed by innotek and Sun Microsystems), for legacy and KVM hypervisor</entry>
  98           </row>
  99
 100           <row>
 101             <entry><varname>powervm</varname></entry>
 102             <entry>IBM PowerVM hypervisor — comes as firmware with some IBM POWER servers</entry>
 103           </row>
 104
 105           <row>
 106             <entry><varname>xen</varname></entry>
 107             <entry>Xen hypervisor (only domU, not dom0)</entry>
 108           </row>
 109
 110           <row>
 111             <entry><varname>bochs</varname></entry>
 112             <entry>Bochs Emulator</entry>
 113           </row>
 114
 115           <row>
 116             <entry><varname>uml</varname></entry>
 117             <entry>User-mode Linux</entry>
 118           </row>
 119
 120           <row>
 121             <entry><varname>parallels</varname></entry>
 122             <entry>Parallels Desktop, Parallels Server</entry>
 123           </row>
 124
 125           <row>
 126             <entry><varname>bhyve</varname></entry>
 127             <entry>bhyve, FreeBSD hypervisor</entry>
 128           </row>
 129
 130           <row>
 131             <entry><varname>qnx</varname></entry>
 132             <entry>QNX hypervisor</entry>
 133           </row>
 134
 135           <row>
 136             <entry><varname>acrn</varname></entry>
 137             <entry><ulink url="https://projectacrn.org">ACRN hypervisor</ulink></entry>
 138           </row>
 139
 140           <row>
 141             <entry><varname>apple</varname></entry>
 142             <entry><ulink url="https://developer.apple.com/documentation/virtualization">Apple Virtualization.framework</ulink></entry>
 143           </row>
 144
 145           <row>
 146             <entry><varname>sre</varname></entry>
 147             <entry><ulink url="https://www.lockheedmartin.com/en-us/products/Hardened-Security-for-Intel-Processors.html">LMHS SRE hypervisor</ulink></entry>
 148           </row>
 149
 150           <row>
 151             <entry valign="top" morerows="9">Container</entry>
 152             <entry><varname>openvz</varname></entry>
 153             <entry>OpenVZ/Virtuozzo</entry>
 154           </row>
 155
 156           <row>
 157             <entry><varname>lxc</varname></entry>
 158             <entry>Linux container implementation by LXC</entry>
 159           </row>
 160
 161           <row>
 162             <entry><varname>lxc-libvirt</varname></entry>
 163             <entry>Linux container implementation by libvirt</entry>
 164           </row>
 165
 166           <row>
 167             <entry><varname>systemd-nspawn</varname></entry>
 168             <entry>systemd's minimal container implementation, see <citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>1</manvolnum></citerefentry></entry>
 169           </row>
 170
 171           <row>
 172             <entry><varname>docker</varname></entry>
 173             <entry>Docker container manager</entry>
 174           </row>
 175
 176           <row>
 177             <entry><varname>podman</varname></entry>
 178             <entry><ulink url="https://podman.io">Podman</ulink> container manager</entry>
 179           </row>
 180
 181           <row>
 182             <entry><varname>rkt</varname></entry>
 183             <entry>rkt app container runtime</entry>
 184           </row>
 185
 186           <row>
 187             <entry><varname>wsl</varname></entry>
 188             <entry><ulink url="https://docs.microsoft.com/en-us/windows/wsl/about">Windows Subsystem for Linux</ulink></entry>
 189           </row>
 190
 191           <row>
 192             <entry><varname>proot</varname></entry>
 193             <entry><ulink url="https://proot-me.github.io/">proot</ulink> userspace chroot/bind mount emulation</entry>
 194           </row>
 195
 196           <row>
 197             <entry><varname>pouch</varname></entry>
 198             <entry><ulink url="https://github.com/alibaba/pouch">Pouch</ulink> Container Engine</entry>
 199           </row>
 200         </tbody>
 201       </tgroup>
 202     </table>
 203
 204     <para>If multiple virtualization solutions are used, only the
 205     "innermost" is detected and identified. That means if both
 206     machine and container virtualization are used in
 207     conjunction, only the latter will be identified (unless
 208     <option>--vm</option> is passed).</para>
 209     <para> Windows Subsystem for Linux is not a Linux container,
 210     but an environment for running Linux userspace applications on
 211     top of the Windows kernel using a Linux-compatible interface.
 212     WSL is categorized as a container for practical purposes.
 213     Multiple WSL environments share the same kernel and services
 214     should generally behave like when being run in a container.</para>
 215   </refsect1>
 216
 217   <refsect1>
 218     <title>Options</title>
 219
 220     <para>The following options are understood:</para>
 221
 222     <variablelist>
 223       <varlistentry>
 224         <term><option>-c</option></term>
 225         <term><option>--container</option></term>
 226
 227         <listitem><para>Only detects container virtualization (i.e.
 228         shared kernel virtualization).</para></listitem>
 229       </varlistentry>
 230
 231       <varlistentry>
 232         <term><option>-v</option></term>
 233         <term><option>--vm</option></term>
 234
 235         <listitem><para>Only detects hardware virtualization.</para></listitem>
 236       </varlistentry>
 237
 238       <varlistentry>
 239         <term><option>-r</option></term>
 240         <term><option>--chroot</option></term>
 241
 242         <listitem><para>Detect whether invoked in a
 243         <citerefentry><refentrytitle>chroot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 244         environment. In this mode, no output is written, but the return
 245         value indicates whether the process was invoked in a
 246         <function>chroot()</function>
 247         environment or not.</para>
 248
 249         <xi:include href="version-info.xml" xpointer="v228"/></listitem>
 250       </varlistentry>
 251
 252       <varlistentry>
 253         <term><option>--private-users</option></term>
 254
 255         <listitem><para>Detect whether invoked in a user namespace.  In this mode, no
 256         output is written, but the return value indicates whether the process was invoked
 257         inside of a user namespace or not. See
 258         <citerefentry project='man-pages'><refentrytitle>user_namespaces</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 259         for more information.</para>
 260
 261         <xi:include href="version-info.xml" xpointer="v232"/></listitem>
 262       </varlistentry>
 263
 264       <varlistentry>
 265         <term><option>--cvm</option></term>
 266
 267         <listitem><para>Detect whether invoked in a confidential virtual machine.
 268         The result of this detection may be used to disable features that should
 269         not be used in confidential VMs. It must not be used to release security
 270         sensitive information. The latter must only be released after attestation
 271         of the confidential environment.</para>
 272
 273         <xi:include href="version-info.xml" xpointer="v254"/></listitem>
 274       </varlistentry>
 275
 276       <varlistentry>
 277         <term><option>-q</option></term>
 278         <term><option>--quiet</option></term>
 279
 280         <listitem><para>Suppress output of the virtualization
 281         technology identifier.</para></listitem>
 282       </varlistentry>
 283
 284       <varlistentry>
 285         <term><option>--list</option></term>
 286
 287         <listitem><para>Output all currently known and detectable container and VM environments.</para>
 288
 289         <xi:include href="version-info.xml" xpointer="v239"/></listitem>
 290       </varlistentry>
 291
 292       <varlistentry>
 293         <term><option>--list-cvm</option></term>
 294
 295         <listitem><para>Output all currently known and detectable confidential virtualization technologies.</para>
 296
 297         <xi:include href="version-info.xml" xpointer="v254"/></listitem>
 298       </varlistentry>
 299
 300       <xi:include href="standard-options.xml" xpointer="help" />
 301       <xi:include href="standard-options.xml" xpointer="version" />
 302     </variablelist>
 303
 304   </refsect1>
 305
 306   <refsect1>
 307     <title>Exit status</title>
 308
 309     <para>If a virtualization technology is detected, 0 is returned, a
 310     non-zero code otherwise.</para>
 311   </refsect1>
 312
 313   <refsect1>
 314     <title>See Also</title>
 315     <para><simplelist type="inline">
 316       <member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
 317       <member><citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
 318       <member><citerefentry><refentrytitle>chroot</refentrytitle><manvolnum>2</manvolnum></citerefentry></member>
 319       <member><citerefentry project='man-pages'><refentrytitle>namespaces</refentrytitle><manvolnum>7</manvolnum></citerefentry></member>
 320     </simplelist></para>
 321   </refsect1>
 322
 323 </refentry>