1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885
|
.. role:: since
==============================
Domain capabilities XML format
==============================
.. contents::
Overview
--------
Sometimes, when a new domain is to be created it may come handy to know the
capabilities of the hypervisor so the correct combination of devices and drivers
is used. For example, when management application is considering the mode for a
host device's passthrough there are several options depending not only on host,
but on hypervisor in question too. If the hypervisor is qemu then it needs to be
more recent to support VFIO, while legacy KVM is achievable just fine with older
qemus.
The main difference between
`virConnectGetCapabilities <html/libvirt-libvirt-host.html#virConnectGetCapabilities>`__
and the emulator capabilities API is, the former one aims more on the host
capabilities (e.g. NUMA topology, security models in effect, etc.) while the
latter one specializes on the hypervisor capabilities.
While the `Driver Capabilities <formatcaps.html>`__ provides the host
capabilities (e.g NUMA topology, security models in effect, etc.), the Domain
Capabilities provides the hypervisor specific capabilities for Management
Applications to query and make decisions regarding what to utilize.
The Domain Capabilities can provide information such as the correct combination
of devices and drivers that are supported. Knowing which host and hypervisor
specific options are available or supported would allow the management
application to choose an appropriate mode for a pass-through host device as well
as which adapter to utilize.
Some XML elements may be entirely omitted from the domaincapabilities XML,
depending on what the libvirt driver has filled in. Applications should only act
on what is explicitly reported in the domaincapabilities XML. For example, if
<disk supported='yes'/> is present, you can safely assume the driver supports
<disk> devices. If <disk supported='no'/> is present, you can safely assume the
driver does NOT support <disk> devices. If the <disk> block is omitted entirely,
the driver is not indicating one way or the other whether it supports <disk>
devices, and applications should not interpret the missing block to mean any
thing in particular.
Element and attribute overview
------------------------------
A new query interface was added to the virConnect API's to retrieve the XML
listing of the set of domain capabilities ( :since:`Since 1.2.7` ):
``virConnectGetDomainCapabilities`` (`API docs <html/libvirt-libvirt-domain.html#virConnectGetDomainCapabilities>`__)
The root element that emulator capability XML document starts with has name
``domainCapabilities``. It contains at least four direct child elements:
::
<domainCapabilities>
<path>/usr/bin/qemu-system-x86_64</path>
<domain>kvm</domain>
<machine>pc-i440fx-2.1</machine>
<arch>x86_64</arch>
...
</domainCapabilities>
``path``
The full path to the emulator binary. Since not every hypervisor has a
notion of emulator binary this element might be omitted in such drivers.
``domain``
Describes the `virtualization type <formatdomain.html#element-and-attribute-overview>`__ (or so
called domain type).
``machine``
The domain's `machine type <formatdomain.html#bios-bootloader>`__. Since not
every hypervisor has a sense of machine types this element might be omitted
in such drivers.
``arch``
The domain's `architecture <formatdomain.html#bios-bootloader>`__.
CPU Allocation
~~~~~~~~~~~~~~
Before any devices capability occurs, there might be info on domain wide
capabilities, e.g. virtual CPUs:
::
<domainCapabilities>
...
<vcpu max='255'/>
...
</domainCapabilities>
``vcpu``
The maximum number of supported virtual CPUs
BIOS bootloader
~~~~~~~~~~~~~~~
Sometimes users might want to tweak some BIOS knobs or use UEFI. For cases like
that, `os <formatdomain.html#bios-bootloader>`__ element exposes what values can
be passed to its children.
::
<domainCapabilities>
...
<os supported='yes'>
<enum name='firmware'>
<value>bios</value>
<value>efi</value>
</enum>
<loader supported='yes'>
<value>/usr/share/OVMF/OVMF_CODE.fd</value>
<enum name='type'>
<value>rom</value>
<value>pflash</value>
</enum>
<enum name='readonly'>
<value>yes</value>
<value>no</value>
</enum>
<enum name='secure'>
<value>yes</value>
<value>no</value>
</enum>
</loader>
</os>
...
<domainCapabilities>
The ``firmware`` enum corresponds to the ``firmware`` attribute of the ``os``
element in the domain XML. The presence of this enum means libvirt is capable of
the so-called firmware auto-selection feature. And the listed firmware values
represent the accepted input in the domain XML. Note that the ``firmware`` enum
reports only those values for which a firmware "descriptor file" exists on the
host. Firmware descriptor file is a small JSON document that describes details
about a given BIOS or UEFI binary on the host, e.g. the firmware binary path,
its architecture, supported machine types, NVRAM template, etc. This ensures
that the reported values won't cause a failure on guest boot.
For the ``loader`` element, the following can occur:
``value``
List of known firmware binary paths. Currently this is used only to advertise
the known location of OVMF binaries for QEMU. OVMF binaries will only be
listed if they actually exist on host.
``type``
Whether the boot loader is a typical BIOS (``rom``) or a UEFI firmware
(``pflash``). Each ``value`` sub-element under the ``type`` enum represents a
possible value for the ``type`` attribute for the <loader/> element in the
domain XML. E.g. the presence of ``pfalsh`` under the ``type`` enum means
that a domain XML can use UEFI firmware via: <loader/> type="pflash"
...>/path/to/the/firmware/binary/</loader>.
``readonly``
Options for the ``readonly`` attribute of the <loader/> element in the domain
XML.
``secure``
Options for the ``secure`` attribute of the <loader/> element in the domain
XML. Note that the value ``yes`` is listed only if libvirt detects a firmware
descriptor file that has path to an OVMF binary that supports Secure boot,
and lists its architecture and supported machine type.
CPU configuration
~~~~~~~~~~~~~~~~~
The ``cpu`` element exposes options usable for configuring `guest
CPUs <formatdomain.html#cpu-model-and-topology>`__.
::
<domainCapabilities>
...
<cpu>
<mode name='host-passthrough' supported='yes'>
<enum name='hostPassthroughMigratable'>
<value>on</value>
<value>off</value>
</enum>
</mode>
<mode name='maximum' supported='yes'>
<enum name='maximumMigratable'>
<value>on</value>
<value>off</value>
</enum>
</mode>
<mode name='host-model' supported='yes'>
<model fallback='allow'>Broadwell</model>
<vendor>Intel</vendor>
<maxphysaddr mode="passthrough" limit="39"/>
<feature policy='disable' name='aes'/>
<feature policy='require' name='vmx'/>
</mode>
<mode name='custom' supported='yes'>
<model usable='no' deprecated='no' vendor='Intel' canonical='Broadwell-v1'>Broadwell</model>
<blockers model='Broadwell'>
<feature name='hle'/>
<feature name='rtm'/>
</blockers>
<model usable='yes' deprecated='no' vendor='Intel' canonical='Broadwell-v2'>Broadwell-noTSX</model>
<model usable='no' deprecated='no' vendor='AMD'>EPYC-Milan</model>
<blockers model='EPYC-Milan'>
<feature name='clzero'/>
<feature name='cr8legacy'/>
<feature name='fxsr_opt'/>
<feature name='misalignsse'/>
<feature name='mmxext'/>
<feature name='osvw'/>
<feature name='perfctr_core'/>
<feature name='sse4a'/>
<feature name='wbnoinvd'/>
<feature name='xsaveerptr'/>
</blockers>
<model usable='no' deprecated='yes' vendor='Intel'>Haswell</model>
<blockers model='Haswell'>
<feature name='hle'/>
<feature name='rtm'/>
</blockers>
...
</mode>
</cpu>
...
<domainCapabilities>
Each CPU mode understood by libvirt is described with a ``mode`` element which
tells whether the particular mode is supported and provides (when applicable)
more details about it:
``host-passthrough``
The ``hostPassthroughMigratable`` enum shows possible values of the
``migratable`` attribute for the <cpu> element with
``mode='host-passthrough'`` in the domain XML.
``host-model``
If ``host-model`` is supported by the hypervisor, the ``mode`` describes the
guest CPU which will be used when starting a domain with ``host-model`` CPU.
The hypervisor specifics (such as unsupported CPU models or features, machine
type, etc.) may be accounted for in this guest CPU specification and thus the
CPU can be different from the one shown in host capabilities XML. This is
indicated by the ``fallback`` attribute of the ``model`` sub element:
``allow`` means not all specifics were accounted for and thus the CPU a guest
will see may be different; ``forbid`` indicates that the CPU a guest will see
should match this CPU definition. The optional ``maxphysaddr`` element
reports physical address size of the host CPU if this value is available and
applicable for the requested domain type. This is useful for computing
baseline CPU definition which should be compatible with several hosts.
``custom``
The ``mode`` element contains a list of supported CPU models, each described
by a dedicated ``model`` element. The ``usable`` attribute specifies whether
the model can be used directly on the host. A special value ``unknown``
indicates libvirt does not have enough information to provide the usability
data. When ``usable='no'`` the corresponding model cannot be used without
disabling some features that the CPU of such model is expected to have.
:since:`Since 10.9.0` each CPU model with ``usable='no'`` is followed by
a corresponding ``blockers`` element containing a list of features blocking
usability of the CPU model. Models marked as usable (``usable='yes'``) can
be safely used in domain XMLs with ``check='none'`` as the hypervisor
guarantees the model can be used on the current host and additional checks
done by libvirt are redundant. :since:`Since 10.2.0` libvirt automatically
detects this situation and avoids the redundant checks even when
``check='partial'`` is used, with older releases disabling libvirt checks
via ``check='none'`` for such models is recommended to avoid needless issues
with starting domains when libvirt's definition of a particular model
differs from hypervisor's definition. The ``deprecated`` attribute reflects
the hypervisor's policy on usage of this model :since:`(since 7.1.0)`. The
``vendor`` attribute :since:`(since 8.9.0)` contains the vendor of the CPU
model for users who want to use CPU models with specific vendors only. CPU
models with undefined vendor will be listed with ``vendor='unkwnown'``. The
``canonical`` attribute :since:`(since 10.10.0)` contains a canonical name of
the CPU model if the model is actually an alias to another one.
I/O Threads
~~~~~~~~~~~
The ``iothread`` elements indicates whether or not `I/O
threads <formatdomain.html#iothreads-allocation>`__ are supported.
::
<domainCapabilities>
...
<iothread supported='yes'/>
...
<domainCapabilities>
Memory Backing
~~~~~~~~~~~~~~
The ``memory backing`` element indicates whether or not `memory
backing <formatdomain.html#memory-backing>`__ is supported.
::
<domainCapabilities>
...
<memoryBacking supported='yes'>
<enum name='sourceType'>
<value>anonymous</value>
<value>file</value>
<value>memfd</value>
</enum>
</memoryBacking>
...
<domainCapabilities>
``sourceType``
Options for the ``type`` attribute of the <memoryBacking><source> element.
Devices
~~~~~~~
Another set of XML elements describe the supported devices and their
capabilities. All devices occur as children of the main ``devices`` element.
::
<domainCapabilities>
...
<devices>
<disk supported='yes'>
<enum name='diskDevice'>
<value>disk</value>
<value>cdrom</value>
<value>floppy</value>
<value>lun</value>
</enum>
...
</disk>
<hostdev supported='no'/>
</devices>
</domainCapabilities>
Reported capabilities are expressed as an enumerated list of available options
for each of the element or attribute. For example, the <disk/> element has an
attribute ``device`` which can support the values ``disk``, ``cdrom``,
``floppy``, or ``lun``.
Hard drives, floppy disks, CDROMs
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Disk capabilities are exposed under the ``disk`` element. For instance:
::
<domainCapabilities>
...
<devices>
<disk supported='yes'>
<enum name='diskDevice'>
<value>disk</value>
<value>cdrom</value>
<value>floppy</value>
<value>lun</value>
</enum>
<enum name='bus'>
<value>ide</value>
<value>fdc</value>
<value>scsi</value>
<value>virtio</value>
<value>xen</value>
<value>usb</value>
<value>sata</value>
<value>sd</value>
</enum>
</disk>
...
</devices>
</domainCapabilities>
``diskDevice``
Options for the ``device`` attribute of the <disk/> element.
``bus``
Options for the ``bus`` attribute of the <target/> element for a <disk/>.
Graphical framebuffers
^^^^^^^^^^^^^^^^^^^^^^
Graphics device capabilities are exposed under the ``graphics`` element. For
instance:
::
<domainCapabilities>
...
<devices>
<graphics supported='yes'>
<enum name='type'>
<value>sdl</value>
<value>vnc</value>
<value>spice</value>
</enum>
</graphics>
...
</devices>
</domainCapabilities>
``type``
Options for the ``type`` attribute of the <graphics/> element.
Video device
^^^^^^^^^^^^
Video device capabilities are exposed under the ``video`` element. For instance:
::
<domainCapabilities>
...
<devices>
<video supported='yes'>
<enum name='modelType'>
<value>vga</value>
<value>cirrus</value>
<value>vmvga</value>
<value>qxl</value>
<value>virtio</value>
</enum>
</video>
...
</devices>
</domainCapabilities>
``modelType``
Options for the ``type`` attribute of the <video><model> element.
Host device assignment
^^^^^^^^^^^^^^^^^^^^^^
Some host devices can be passed through to a guest (e.g. USB, PCI and SCSI).
Well, only if the following is enabled:
::
<domainCapabilities>
...
<devices>
<hostdev supported='yes'>
<enum name='mode'>
<value>subsystem</value>
<value>capabilities</value>
</enum>
<enum name='startupPolicy'>
<value>default</value>
<value>mandatory</value>
<value>requisite</value>
<value>optional</value>
</enum>
<enum name='subsysType'>
<value>usb</value>
<value>pci</value>
<value>scsi</value>
</enum>
<enum name='capsType'>
<value>storage</value>
<value>misc</value>
<value>net</value>
</enum>
<enum name='pciBackend'>
<value>default</value>
<value>kvm</value>
<value>vfio</value>
<value>xen</value>
</enum>
</hostdev>
</devices>
</domainCapabilities>
``mode``
Options for the ``mode`` attribute of the <hostdev/> element.
``startupPolicy``
Options for the ``startupPolicy`` attribute of the <hostdev/> element.
``subsysType``
Options for the ``type`` attribute of the <hostdev/> element in case of
``mode="subsystem"``.
``capsType``
Options for the ``type`` attribute of the <hostdev/> element in case of
``mode="capabilities"``.
``pciBackend``
Options for the ``name`` attribute of the <driver/> element.
RNG device
^^^^^^^^^^
RNG device capabilities are exposed under the ``rng`` element. For instance:
::
<domainCapabilities>
...
<devices>
<rng supported='yes'>
<enum name='model'>
<value>virtio</value>
<value>virtio-transitional</value>
<value>virtio-non-transitional</value>
</enum>
<enum name='backendModel'>
<value>random</value>
<value>egd</value>
<value>builtin</value>
</enum>
</rng>
...
</devices>
</domainCapabilities>
``model``
Options for the ``model`` attribute of the <rng> element.
``backendModel``
Options for the ``model`` attribute of the <rng><backend> element.
Filesystem device
^^^^^^^^^^^^^^^^^
Filesystem device capabilities are exposed under the ``filesystem`` element. For
instance:
::
<domainCapabilities>
...
<devices>
<filesystem supported='yes'>
<enum name='driverType'>
<value>default</value>
<value>path</value>
<value>handle</value>
<value>virtiofs</value>
</enum>
</filesystem>
...
</devices>
</domainCapabilities>
``driverType``
Options for the ``type`` attribute of the <filesystem><driver> element.
TPM device
^^^^^^^^^^
TPM device capabilities are exposed under the ``tpm`` element. For instance:
::
<domainCapabilities>
...
<devices>
<tpm supported='yes'>
<enum name='model'>
<value>tpm-tis</value>
<value>tpm-crb</value>
</enum>
<enum name='backendModel'>
<value>passthrough</value>
<value>emulator</value>
</enum>
<enum name='backendVersion'>
<value>1.2</value>
<value>2.0</value>
</enum>
</tpm>
...
</devices>
</domainCapabilities>
``model``
Options for the ``model`` attribute of the ``<tpm/>`` element.
``backendModel``
Options for the ``type`` attribute of the ``<tpm><backend/>`` element.
``backendVersion``
Options for the ``version`` attribute of the ``<tpm><backend/>`` element.
USB redirect device
^^^^^^^^^^^^^^^^^^^
USB redirdev device capabilities are exposed under the ``redirdev`` element. For instance:
::
<domainCapabilities>
...
<devices>
<redirdev supported='yes'>
<enum name='bus'>
<value>usb</value>
</enum>
</redirdev>
...
</devices>
</domainCapabilities>
``bus``
Options for the ``bus`` attribute of the ``<redirdev/>`` element.
Channel device
^^^^^^^^^^^^^^
Channel device capabilities are exposed under the ``channel`` element. For instance:
::
<domainCapabilities>
...
<devices>
<channel supported='yes'>
<enum name='type'>
<value>pty</value>
<value>unix</value>
<value>spicevmc</value>
</enum>
</channel
...
</devices>
</domainCapabilities>
``type``
Options for the ``type`` attribute of the ``<channel/>`` element.
Crypto device
^^^^^^^^^^^^^^
Crypto device capabilities are exposed under the ``crypto`` element. For instance:
::
<domainCapabilities>
...
<devices>
<crypto supported='yes'>
<enum name='model'>
<value>virtio</value>
</enum>
<enum name='type'>
<value>qemu</value>
</enum>
<enum name='backendModel'>
<value>builtin</value>
<value>lkcf</value>
</enum>
</crypto>
...
</devices>
</domainCapabilities>
``model``
Options for the ``model`` attribute of the ``<crypto/>`` element.
``type``
Options for the ``type`` attribute of the ``<crypto/>`` element.
``backendModel``
Options for the ``backendModel`` attribute of the ``<crypto><backend/>`` element.
Interface device
^^^^^^^^^^^^^^^^
Interface device corresponds to `network interface
<formatdomain.html#network-interfaces>`__ (``<interface/>``) in domain XML.
::
<domainCapabilities>
...
<devices>
<interface supported='yes'>
<enum name='backendType'>
<value>default</value>
<value>passt</value>
</enum>
</interface>
...
</devices>
</domainCapabilities>
``backendType``
Options for the ``type`` attribute of the ``<backend/>`` element
Panic device
^^^^^^^^^^^^
Interface device corresponds to `panic device
<formatdomain.html#panic-device>`__ (``<panic/>``) in domain XML.
::
<domainCapabilities>
...
<devices>
<panic supported='yes'>
<enum name='model'>
<value>isa</value>
<value>hyperv</value>
</enum>
</panic>
...
</devices>
</domainCapabilities>
``model``
Options for the ``model`` attribute of the ``<panic/>`` element
Features
~~~~~~~~
One more set of XML elements describe the supported features and their
capabilities. All features occur as children of the main ``features`` element.
::
<domainCapabilities>
...
<features>
<gic supported='yes'>
<enum name='version'>
<value>2</value>
<value>3</value>
</enum>
</gic>
<vmcoreinfo supported='yes'/>
<genid supported='yes'/>
<backingStoreInput supported='yes'/>
<backup supported='yes'/>
<async-teardown supported='yes'/>
<tdx supported='yes'/>
<sev>
<cbitpos>47</cbitpos>
<reduced-phys-bits>1</reduced-phys-bits>
</sev>
<sgx supported='yes'>
<flc>no</flc>
<sgx1>yes</sgx1>
<sgx2>no</sgx2>
<section_size unit='KiB'>524288</section_size>
<sections>
<section node='0' size='262144' unit='KiB'/>
<section node='1' size='262144' unit='KiB'/>
</sections>
</sgx>
<hyperv supported='yes'>
<enum name='features'>
<value>relaxed</value>
<value>vapic</value>
</enum>
</hyperv>
</features>
</domainCapabilities>
Reported capabilities are expressed as an enumerated list of possible values for
each of the elements or attributes. For example, the ``gic`` element has an
attribute ``version`` which can support the values ``2`` or ``3``.
For information about the purpose of each feature, see the `relevant
section <formatdomain.html#hypervisor-features>`__ in the domain XML documentation.
GIC capabilities
^^^^^^^^^^^^^^^^
GIC capabilities are exposed under the ``gic`` element.
``version``
Options for the ``version`` attribute of the ``gic`` element.
vmcoreinfo
^^^^^^^^^^
Reports whether the vmcoreinfo feature can be enabled.
genid
^^^^^
Reports whether the genid feature can be used by the domain.
backingStoreInput
^^^^^^^^^^^^^^^^^
Reports whether the hypervisor will obey the <backingStore> elements configured
for a <disk> when booting the guest, hotplugging the disk to a running guest, or
similar. :since:`(Since 5.10)`
backup
^^^^^^
Reports whether the hypervisor supports the backup, checkpoint, and related
features. (``virDomainBackupBegin``, ``virDomainCheckpointCreateXML`` etc). The
presence of the ``backup`` element even if ``supported='no'`` implies that the
``VIR_DOMAIN_UNDEFINE_CHECKPOINTS_METADATA`` flag for ``virDomainUndefine`` is
supported.
async-teardown
^^^^^^^^^^^^^^
Reports whether the asynchronous teardown feature can be enabled.
s390-pv capability
^^^^^^^^^^^^^^^^^^
Reports whether the hypervisor supports the Protected Virtualization. In order
to use Protected Virtualization with libvirt have a look at the `launchSecurity
element in the domain XML <formatdomain.html#launch-security>`__. For more
details on the Protected Virtualization feature please see `Protected
Virtualization on s390 <kbase/s390_protected_virt.html>`__.
ps2 capability
^^^^^^^^^^^^^^
Reports whether it is possible to disable the machine's built-in PS/2
controller.
SEV capabilities
^^^^^^^^^^^^^^^^
AMD Secure Encrypted Virtualization (SEV) capabilities are exposed under the
``sev`` element. SEV is an extension to the AMD-V architecture which supports
running virtual machines (VMs) under the control of a hypervisor. When
supported, guest owner can create a VM whose memory contents will be
transparently encrypted with a key unique to that VM.
For more details on the SEV feature, please follow resources in the AMD
developer's document store. In order to use SEV with libvirt have a look at `SEV
in domain XML <formatdomain.html#launch-security>`__
``cbitpos``
When memory encryption is enabled, one of the physical address bits (aka the
C-bit) is utilized to mark if a memory page is protected. The C-bit position
is Hypervisor dependent.
``reducedPhysBits``
When memory encryption is enabled, we lose certain bits in physical address
space. The number of bits we lose is hypervisor dependent.
``maxGuests``
The maximum number of SEV guests that can be launched on the host. This value
may be configurable in the firmware for some hosts.
``maxESGuests``
The maximum number of SEV-ES guests that can be launched on the host. This
value may be configurable in the firmware for some hosts.
SGX capabilities
^^^^^^^^^^^^^^^^
Intel Software Guard Extensions (Intel SGX) capabilities are exposed under the
``sgx`` element.
Intel SGX helps protect data in use via unique application isolation technology.
Protect selected code and data from modification using hardened enclaves with
Intel SGX.
For more details on the SGX feature, please follow resources in the SGX developer's
document store. In order to use SGX with libvirt have a look at `SGX in domain XML
<formatdomain.html#memory-devices>`__
``flc``
FLC (Flexible Launch Control), not strictly part of SGX2, but was not part of
original SGX hardware either.
``sgx1``
the sgx version 1.
``sgx2``
The sgx version 2.
``section_size``
The size of the SGX enclave page cache (called EPC).
``sections``
The sections of the SGX enclave page cache (called EPC).
Hyper-V Enlightenments
^^^^^^^^^^^^^^^^^^^^^^
Report which features improving behavior of guests running Microsoft Windows
are supported. The ``features`` enum corresponds to the ``<hyperv/>`` element
(well, its children) as documented in `Hypervisor features
<formatdomain.html#hypervisor-features>`__. The ``defaults`` element then
contains child elements describing default values as reported by hypervisor,
e.g. whether direct or extended TLB flushes are available. :since:`(since
11.9.0)`
Launch security
^^^^^^^^^^^^^^^
The ``launchSecurity`` element exposes supported aspects of encrypted guests.
The ``sectype`` enum corresponds to ``type`` attribute of ``<launchSecurity/>``
element as documented in `Launch Security
<formatdomain.html#launch-security>`__. :since:`(Since 10.5.0)` For additional
information on individual types, see sections above: `s390-pv capability`_ for
S390 PV, `SEV capabilities`_ for AMD SEV and/or AMD SEV-SNP.
|