$> sudo virsh domcapabilities
<domainCapabilities>
  <path>/usr/bin/qemu-system-x86_64</path>
  <domain>kvm</domain>
  <machine>pc-i440fx-3.1</machine>
  <arch>x86_64</arch>
  <vcpu max='255'/>
  <iothreads supported='yes'/>
  <os supported='yes'>
    <loader supported='yes'>
      <value>/usr/share/edk2/ovmf/OVMF_CODE.fd</value>
      <value>/usr/share/edk2/aarch64/QEMU_EFI-pflash.raw</value>
      <enum name='type'>
        <value>rom</value>
        <value>pflash</value>
      </enum>
      <enum name='readonly'>
        <value>yes</value>
        <value>no</value>
      </enum>
    </loader>
  </os>
  <cpu>
    <mode name='host-passthrough' supported='yes'/>
    <mode name='host-model' supported='yes'>
      <model fallback='forbid'>Skylake-Client-IBRS</model>
      <vendor>Intel</vendor>
      <feature policy='require' name='ss'/>
      <feature policy='require' name='vmx'/>
      <feature policy='require' name='hypervisor'/>
      <feature policy='require' name='tsc_adjust'/>
      <feature policy='require' name='clflushopt'/>
      <feature policy='require' name='umip'/>
      <feature policy='require' name='arch-capabilities'/>
      <feature policy='require' name='ssbd'/>
      <feature policy='require' name='xsaves'/>
      <feature policy='require' name='pdpe1gb'/>
      <feature policy='require' name='invtsc'/>
    </mode>
    <mode name='custom' supported='yes'>
      <model usable='yes'>qemu64</model>
      <model usable='yes'>qemu32</model>
      <model usable='no'>phenom</model>
      <model usable='yes'>pentium3</model>
      <model usable='yes'>pentium2</model>
      <model usable='yes'>pentium</model>
      <model usable='yes'>n270</model>
      <model usable='yes'>kvm64</model>
      <model usable='yes'>kvm32</model>
      <model usable='yes'>coreduo</model>
      <model usable='yes'>core2duo</model>
      <model usable='no'>athlon</model>
      <model usable='yes'>Westmere-IBRS</model>
      <model usable='yes'>Westmere</model>
      <model usable='no'>Skylake-Server-IBRS</model>
      <model usable='no'>Skylake-Server</model>
      <model usable='yes'>Skylake-Client-IBRS</model>
      <model usable='yes'>Skylake-Client</model>
      <model usable='yes'>SandyBridge-IBRS</model>
      <model usable='yes'>SandyBridge</model>
      <model usable='yes'>Penryn</model>
      <model usable='no'>Opteron_G5</model>
      <model usable='no'>Opteron_G4</model>
      <model usable='no'>Opteron_G3</model>
      <model usable='yes'>Opteron_G2</model>
      <model usable='yes'>Opteron_G1</model>
      <model usable='yes'>Nehalem-IBRS</model>
      <model usable='yes'>Nehalem</model>
      <model usable='yes'>IvyBridge-IBRS</model>
      <model usable='yes'>IvyBridge</model>
      <model usable='no'>Icelake-Server</model>
      <model usable='no'>Icelake-Client</model>
      <model usable='yes'>Haswell-noTSX-IBRS</model>
      <model usable='yes'>Haswell-noTSX</model>
      <model usable='yes'>Haswell-IBRS</model>
      <model usable='yes'>Haswell</model>
      <model usable='no'>EPYC-IBPB</model>
      <model usable='no'>EPYC</model>
      <model usable='yes'>Conroe</model>
      <model usable='yes'>Broadwell-noTSX-IBRS</model>
      <model usable='yes'>Broadwell-noTSX</model>
      <model usable='yes'>Broadwell-IBRS</model>
      <model usable='yes'>Broadwell</model>
      <model usable='yes'>486</model>
    </mode>
  </cpu>
  <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>usb</value>
        <value>sata</value>
      </enum>
    </disk>
    <graphics supported='yes'>
      <enum name='type'>
        <value>sdl</value>
        <value>vnc</value>
        <value>spice</value>
      </enum>
    </graphics>
    <video supported='yes'>
      <enum name='modelType'>
        <value>vga</value>
        <value>cirrus</value>
        <value>vmvga</value>
        <value>qxl</value>
        <value>virtio</value>
      </enum>
    </video>
    <hostdev supported='yes'>
      <enum name='mode'>
        <value>subsystem</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'/>
      <enum name='pciBackend'/>
    </hostdev>
  </devices>
  <features>
    <gic supported='no'/>
    <vmcoreinfo supported='yes'/>
    <genid supported='yes'/>
    <sev supported='no'/>
  </features>
</domainCapabilities>