docs/drvxen.html.in

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   5     <h1>libxl hypervisor driver for Xen</h1>
   6
   7     <ul id="toc"></ul>
   8
   9     <p>
  10       The libvirt libxl driver provides the ability to manage virtual
  11       machines on any Xen release from 4.6.0 onwards.
  12     </p>
  13
  14     <h2><a id="project">Project Links</a></h2>
  15
  16     <ul>
  17       <li>
  18         The <a href="https://www.xenproject.org">Xen</a>
  19         hypervisor on Linux and Solaris hosts
  20       </li>
  21     </ul>
  22
  23     <h2><a id="prereq">Deployment pre-requisites</a></h2>
  24
  25     <p>
  26       The libvirt libxl driver uses Xen's libxl API, also known as
  27       libxenlight, to implement libvirt's hypervisor driver
  28       functionality. libxl provides a consolidated interface for
  29       managing a Xen host and its virtual machines, unlike old
  30       versions of Xen where applications often had to communicate
  31       with xend, xenstored, and the hypervisor itself via hypercalls.
  32       With libxl the only pre-requisit is a properly installed Xen
  33       host with the libxl toolstack running in a service domain
  34       (often Domain-0).
  35     </p>
  36
  37     <h2><a id="uri">Connections to libxl driver</a></h2>
  38
  39     <p>
  40       The libvirt libxl driver is a single-instance privileged driver,
  41       with a driver name of 'xen'. Some example connection URIs for
  42       the libxl driver are:
  43     </p>
  44
  45 <pre>
  46 xen:///system                     (local access, direct)
  47 xen+unix:///system                (local access, via daemon)
  48 xen://example.com/system          (remote access, TLS/x509)
  49 xen+tcp://example.com/system      (remote access, SASl/Kerberos)
  50 xen+ssh://root@example.com/system (remote access, SSH tunnelled)
  51 </pre>
  52
  53     <h2><a id="imex">Import and export of libvirt domain XML configs</a></h2>
  54
  55     <p>
  56       The libxl driver currently supports three native
  57       config formats. The first, known as <code>xen-xm</code>, is the
  58       original Xen virtual machine config format used by the legacy
  59       xm/xend toolstack. The second, known as <code>xen-sxpr</code>,
  60       is also one of the original formats that was used by xend's
  61       legacy HTTP RPC service (<span class='removed'>removed in 5.6.0</span>)
  62     </p>
  63
  64     <p>
  65       The third format is <code>xen-xl</code>, which is the virtual
  66       machine config format supported by modern Xen. The <code>xen-xl</code>
  67       format is described in the xl.cfg(5) man page.
  68     </p>
  69
  70     <h3><a id="xmlimport">Converting from XM config files to domain XML</a></h3>
  71
  72     <p>
  73       The <code>virsh domxml-from-native</code> provides a way to convert an
  74       existing set of xl, xm, or sxpr config files to libvirt Domain XML,
  75       which can then be used by libvirt.
  76     </p>
  77
  78     <pre>$ virsh -c xen:///system domxml-from-native xen-xm rhel5.cfg
  79 &lt;domain type='xen'&gt;
  80   &lt;name&gt;rhel5pv&lt;/name&gt;
  81   &lt;uuid&gt;8f07fe28-753f-2729-d76d-bdbd892f949a&lt;/uuid&gt;
  82   &lt;memory&gt;2560000&lt;/memory&gt;
  83   &lt;currentMemory&gt;307200&lt;/currentMemory&gt;
  84   &lt;vcpu&gt;4&lt;/vcpu&gt;
  85   &lt;bootloader&gt;/usr/bin/pygrub&lt;/bootloader&gt;
  86   &lt;os&gt;
  87     &lt;type arch='x86_64' machine='xenpv'&gt;linux&lt;/type&gt;
  88   &lt;/os&gt;
  89   &lt;clock offset='utc'/&gt;
  90   &lt;on_poweroff&gt;destroy&lt;/on_poweroff&gt;
  91   &lt;on_reboot&gt;restart&lt;/on_reboot&gt;
  92   &lt;on_crash&gt;restart&lt;/on_crash&gt;
  93   &lt;devices&gt;
  94     &lt;disk type='file' device='disk'&gt;
  95       &lt;driver name='tap' type='aio'/&gt;
  96       &lt;source file='/var/lib/xen/images/rhel5pv.img'/&gt;
  97       &lt;target dev='xvda' bus='xen'/&gt;
  98     &lt;/disk&gt;
  99     &lt;disk type='file' device='disk'&gt;
 100       &lt;driver name='tap' type='qcow'/&gt;
 101       &lt;source file='/root/qcow1-xen.img'/&gt;
 102       &lt;target dev='xvdd' bus='xen'/&gt;
 103     &lt;/disk&gt;
 104     &lt;interface type='bridge'&gt;
 105       &lt;mac address='00:16:3e:60:36:ba'/&gt;
 106       &lt;source bridge='xenbr0'/&gt;
 107     &lt;/interface&gt;
 108     &lt;console type='pty'&gt;
 109       &lt;target port='0'/&gt;
 110     &lt;/console&gt;
 111     &lt;input type='mouse' bus='xen'/&gt;
 112     &lt;graphics type='vnc' port='-1' autoport='yes' listen='0.0.0.0'/&gt;
 113   &lt;/devices&gt;
 114 &lt;/domain&gt;</pre>
 115
 116     <h3><a id="xmlexport">Converting from domain XML to XM config files</a></h3>
 117
 118     <p>
 119       The <code>virsh domxml-to-native</code> provides a way to convert a
 120       guest description using libvirt Domain XML into xl, xm, or sxpr config
 121       format.
 122     </p>
 123
 124     <pre>$ virsh -c xen:///system domxml-to-native xen-xm rhel5pv.xml
 125 name = "rhel5pv"
 126 uuid = "8f07fe28-753f-2729-d76d-bdbd892f949a"
 127 maxmem = 2500
 128 memory = 300
 129 vcpus = 4
 130 bootloader = "/usr/bin/pygrub"
 131 kernel = "/var/lib/xen/boot_kernel.0YK-cS"
 132 ramdisk = "/var/lib/xen/boot_ramdisk.vWgrxK"
 133 extra = "ro root=/dev/VolGroup00/LogVol00 rhgb quiet"
 134 on_poweroff = "destroy"
 135 on_reboot = "restart"
 136 on_crash = "restart"
 137 sdl = 0
 138 vnc = 1
 139 vncunused = 1
 140 vnclisten = "0.0.0.0"
 141 disk = [ "tap:aio:/var/lib/xen/images/rhel5pv.img,xvda,w", "tap:qcow:/root/qcow1-xen.img,xvdd,w" ]
 142 vif = [ "mac=00:16:3e:60:36:ba,bridge=virbr0,script=vif-bridge,vifname=vif5.0" ]</pre>
 143
 144     <h2><a id="xmlconfig">Example domain XML config</a></h2>
 145
 146     <p>
 147       Below are some example XML configurations for Xen guest domains.
 148       For full details of the available options, consult the <a href="formatdomain.html">domain XML format</a>
 149       guide.
 150     </p>
 151
 152     <h3>Paravirtualized guest bootloader</h3>
 153
 154     <p>
 155       Using a bootloader allows a paravirtualized guest to be booted using
 156       a kernel stored inside its virtual disk image
 157     </p>
 158
 159         <pre>&lt;domain type='xen' &gt;
 160   &lt;name&gt;fc8&lt;/name&gt;
 161   &lt;bootloader&gt;/usr/bin/pygrub&lt;/bootloader&gt;
 162   &lt;os&gt;
 163     &lt;type&gt;linux&lt;/type&gt;
 164   &lt;/os&gt;
 165   &lt;memory&gt;131072&lt;/memory&gt;
 166   &lt;vcpu&gt;1&lt;/vcpu&gt;
 167   &lt;devices&gt;
 168     &lt;disk type='file'&gt;
 169       &lt;source file='/var/lib/xen/images/fc4.img'/&gt;
 170       &lt;target dev='sda1'/&gt;
 171     &lt;/disk&gt;
 172     &lt;interface type='bridge'&gt;
 173       &lt;source bridge='xenbr0'/&gt;
 174       &lt;mac address='aa:00:00:00:00:11'/&gt;
 175       &lt;script path='/etc/xen/scripts/vif-bridge'/&gt;
 176     &lt;/interface&gt;
 177     &lt;console tty='/dev/pts/5'/&gt;
 178   &lt;/devices&gt;
 179 &lt;/domain&gt;</pre>
 180
 181     <h3>Paravirtualized guest direct kernel boot</h3>
 182
 183     <p>
 184       For installation of paravirtualized guests it is typical to boot the
 185       domain using a kernel and initrd stored in the host OS
 186     </p>
 187
 188         <pre>&lt;domain type='xen' &gt;
 189   &lt;name&gt;fc8&lt;/name&gt;
 190   &lt;os&gt;
 191     &lt;type&gt;linux&lt;/type&gt;
 192     &lt;kernel&gt;/var/lib/xen/install/vmlinuz-fedora8-x86_64&lt;/kernel&gt;
 193     &lt;initrd&gt;/var/lib/xen/install/initrd-vmlinuz-fedora8-x86_64&lt;/initrd&gt;
 194     &lt;cmdline&gt; kickstart=http://example.com/myguest.ks &lt;/cmdline&gt;
 195   &lt;/os&gt;
 196   &lt;memory&gt;131072&lt;/memory&gt;
 197   &lt;vcpu&gt;1&lt;/vcpu&gt;
 198   &lt;devices&gt;
 199     &lt;disk type='file'&gt;
 200       &lt;source file='/var/lib/xen/images/fc4.img'/&gt;
 201       &lt;target dev='sda1'/&gt;
 202     &lt;/disk&gt;
 203     &lt;interface type='bridge'&gt;
 204       &lt;source bridge='xenbr0'/&gt;
 205       &lt;mac address='aa:00:00:00:00:11'/&gt;
 206       &lt;script path='/etc/xen/scripts/vif-bridge'/&gt;
 207     &lt;/interface&gt;
 208     &lt;graphics type='vnc' port='-1'/&gt;
 209     &lt;console tty='/dev/pts/5'/&gt;
 210   &lt;/devices&gt;
 211 &lt;/domain&gt;</pre>
 212
 213     <h3>Fullyvirtualized guest BIOS boot</h3>
 214
 215     <p>
 216       Fullyvirtualized guests use the emulated BIOS to boot off the primary
 217       harddisk, CDROM or Network PXE ROM.
 218     </p>
 219
 220         <pre>&lt;domain type='xen' id='3'&gt;
 221   &lt;name&gt;fv0&lt;/name&gt;
 222   &lt;uuid&gt;4dea22b31d52d8f32516782e98ab3fa0&lt;/uuid&gt;
 223   &lt;os&gt;
 224     &lt;type&gt;hvm&lt;/type&gt;
 225     &lt;loader&gt;/usr/lib/xen/boot/hvmloader&lt;/loader&gt;
 226     &lt;boot dev='hd'/&gt;
 227   &lt;/os&gt;
 228   &lt;memory&gt;524288&lt;/memory&gt;
 229   &lt;vcpu&gt;1&lt;/vcpu&gt;
 230   &lt;on_poweroff&gt;destroy&lt;/on_poweroff&gt;
 231   &lt;on_reboot&gt;restart&lt;/on_reboot&gt;
 232   &lt;on_crash&gt;restart&lt;/on_crash&gt;
 233   &lt;features&gt;
 234     &lt;pae/&gt;
 235     &lt;acpi/&gt;
 236     &lt;apic/&gt;
 237   &lt;/features&gt;
 238   &lt;clock sync="localtime"/&gt;
 239   &lt;devices&gt;
 240     &lt;emulator&gt;/usr/lib/xen/bin/qemu-dm&lt;/emulator&gt;
 241     &lt;interface type='bridge'&gt;
 242       &lt;source bridge='xenbr0'/&gt;
 243       &lt;mac address='00:16:3e:5d:c7:9e'/&gt;
 244       &lt;script path='vif-bridge'/&gt;
 245     &lt;/interface&gt;
 246     &lt;disk type='file'&gt;
 247       &lt;source file='/var/lib/xen/images/fv0'/&gt;
 248       &lt;target dev='hda'/&gt;
 249     &lt;/disk&gt;
 250     &lt;disk type='file' device='cdrom'&gt;
 251       &lt;source file='/var/lib/xen/images/fc5-x86_64-boot.iso'/&gt;
 252       &lt;target dev='hdc'/&gt;
 253       &lt;readonly/&gt;
 254     &lt;/disk&gt;
 255     &lt;disk type='file' device='floppy'&gt;
 256       &lt;source file='/root/fd.img'/&gt;
 257       &lt;target dev='fda'/&gt;
 258     &lt;/disk&gt;
 259     &lt;graphics type='vnc' port='5904'/&gt;
 260   &lt;/devices&gt;
 261 &lt;/domain&gt;</pre>
 262
 263     <h3>Fullyvirtualized guest direct kernel boot</h3>
 264
 265     <p>
 266       With Xen 3.2.0 or later it is possible to bypass the BIOS and directly
 267       boot a Linux kernel and initrd as a fullyvirtualized domain. This allows
 268       for complete automation of OS installation, for example using the Anaconda
 269       kickstart support.
 270     </p>
 271
 272         <pre>&lt;domain type='xen' id='3'&gt;
 273   &lt;name&gt;fv0&lt;/name&gt;
 274   &lt;uuid&gt;4dea22b31d52d8f32516782e98ab3fa0&lt;/uuid&gt;
 275   &lt;os&gt;
 276     &lt;type&gt;hvm&lt;/type&gt;
 277     &lt;loader&gt;/usr/lib/xen/boot/hvmloader&lt;/loader&gt;
 278     &lt;kernel&gt;/var/lib/xen/install/vmlinuz-fedora8-x86_64&lt;/kernel&gt;
 279     &lt;initrd&gt;/var/lib/xen/install/initrd-vmlinuz-fedora8-x86_64&lt;/initrd&gt;
 280     &lt;cmdline&gt; kickstart=http://example.com/myguest.ks &lt;/cmdline&gt;
 281   &lt;/os&gt;
 282   &lt;memory&gt;524288&lt;/memory&gt;
 283   &lt;vcpu&gt;1&lt;/vcpu&gt;
 284   &lt;on_poweroff&gt;destroy&lt;/on_poweroff&gt;
 285   &lt;on_reboot&gt;restart&lt;/on_reboot&gt;
 286   &lt;on_crash&gt;restart&lt;/on_crash&gt;
 287   &lt;features&gt;
 288     &lt;pae/&gt;
 289     &lt;acpi/&gt;
 290     &lt;apic/&gt;
 291   &lt;/features&gt;
 292   &lt;clock sync="localtime"/&gt;
 293   &lt;devices&gt;
 294     &lt;emulator&gt;/usr/lib/xen/bin/qemu-dm&lt;/emulator&gt;
 295     &lt;interface type='bridge'&gt;
 296       &lt;source bridge='xenbr0'/&gt;
 297       &lt;mac address='00:16:3e:5d:c7:9e'/&gt;
 298       &lt;script path='vif-bridge'/&gt;
 299     &lt;/interface&gt;
 300     &lt;disk type='file'&gt;
 301       &lt;source file='/var/lib/xen/images/fv0'/&gt;
 302       &lt;target dev='hda'/&gt;
 303     &lt;/disk&gt;
 304     &lt;disk type='file' device='cdrom'&gt;
 305       &lt;source file='/var/lib/xen/images/fc5-x86_64-boot.iso'/&gt;
 306       &lt;target dev='hdc'/&gt;
 307       &lt;readonly/&gt;
 308     &lt;/disk&gt;
 309     &lt;disk type='file' device='floppy'&gt;
 310       &lt;source file='/root/fd.img'/&gt;
 311       &lt;target dev='fda'/&gt;
 312     &lt;/disk&gt;
 313     &lt;graphics type='vnc' port='5904'/&gt;
 314   &lt;/devices&gt;
 315 &lt;/domain&gt;</pre>
 316
 317   </body>
 318 </html>