Enable Hyper-V on a Windows 2016 Guest VM

Question

I have a Windows 2016 installation in a virtual machine that I'd like to use Hyper-V with. The host is XUbuntu. However, every time I attempt to enable it I am told that I have not enabled virtualization in the BIOS. Indeed, when using the Intel Processor Identification utility I am told that while my virtualized processor can handle virtualization VT-D is not enabled.

For the VM I am using UEFI as the bios type. I am starting to think that this is the entire problem. Because when I enter the menu there is not one singular option related to virtualization.

Here is the XML for the Windows guest:

<domain type='kvm'>
  <name>Gaming_Server</name>
  <uuid>ef50c993-194f-4090-9e07-917402fd5ae9</uuid>
  <memory unit='KiB'>10485760</memory>
  <currentMemory unit='KiB'>10485760</currentMemory>
  <vcpu placement='static'>10</vcpu>
  <os>
    <type arch='x86_64' machine='pc-q35-2.5'>hvm</type>
    <loader readonly='yes' type='pflash'>/usr/share/OVMF/OVMF_CODE.fd</loader>
    <nvram>/var/lib/libvirt/qemu/nvram/Gaming_Server_VARS.fd</nvram>
    <boot dev='hd'/>
    <bootmenu enable='yes'/>
  </os>
  <features>
    <acpi/>
    <apic/>
    <hyperv>
      <relaxed state='on'/>
      <vapic state='on'/>
      <spinlocks state='on' retries='8191'/>
    </hyperv>
  </features>
  <cpu mode='host-model'>
    <model fallback='allow'/>
    <topology sockets='1' cores='5' threads='2'/>
  </cpu>
  <clock offset='localtime'>
    <timer name='rtc' tickpolicy='catchup'/>
    <timer name='pit' tickpolicy='delay'/>
    <timer name='hpet' present='no'/>
    <timer name='hypervclock' present='yes'/>
  </clock>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>restart</on_crash>
  <pm>
    <suspend-to-mem enabled='no'/>
    <suspend-to-disk enabled='no'/>
  </pm>
  <devices>
    <emulator>/usr/bin/kvm-spice</emulator>
    <disk type='file' device='disk'>
      <driver name='qemu' type='qcow2'/>
      <source file='xxxx/Windows_Gaming_Server.qcow2'/>
      <target dev='vda' bus='virtio'/>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x05' function='0x0'/>
    </disk>
    <disk type='file' device='disk'>
      <driver name='qemu' type='raw' cache='writeback'/>
      <source file='xxxx/Games.img'/>
      <target dev='vdb' bus='virtio'/>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x06' function='0x0'/>
    </disk>
    <disk type='file' device='cdrom'>
      <driver name='qemu' type='raw'/>
      <target dev='sda' bus='sata'/>
      <readonly/>
      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
    </disk>
    <disk type='file' device='cdrom'>
      <driver name='qemu' type='raw'/>
      <source file='xxxx/virtio-win-0.1.126.iso'/>
      <target dev='sdb' bus='sata'/>
      <readonly/>
      <address type='drive' controller='0' bus='0' target='0' unit='1'/>
    </disk>
    <controller type='usb' index='0' model='nec-xhci'>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x03' function='0x0'/>
    </controller>
    <controller type='sata' index='0'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x1f' function='0x2'/>
    </controller>
    <controller type='pci' index='0' model='pcie-root'/>
    <controller type='pci' index='1' model='dmi-to-pci-bridge'>
      <model name='i82801b11-bridge'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x1e' function='0x0'/>
    </controller>
    <controller type='pci' index='2' model='pci-bridge'>
      <model name='pci-bridge'/>
      <target chassisNr='2'/>
      <address type='pci' domain='0x0000' bus='0x01' slot='0x01' function='0x0'/>
    </controller>
    <controller type='virtio-serial' index='0'>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x04' function='0x0'/>
    </controller>
    <interface type='direct'>
      <mac address='52:54:00:ed:2a:69'/>
      <source dev='eno1' mode='bridge'/>
      <model type='rtl8139'/>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x01' function='0x0'/>
    </interface>
    <serial type='pty'>
      <target port='0'/>
    </serial>
    <console type='pty'>
      <target type='serial' port='0'/>
    </console>
    <channel type='spicevmc'>
      <target type='virtio' name='com.redhat.spice.0'/>
      <address type='virtio-serial' controller='0' bus='0' port='1'/>
    </channel>
    <input type='tablet' bus='usb'/>
    <input type='mouse' bus='ps2'/>
    <input type='keyboard' bus='ps2'/>
    <graphics type='spice' autoport='yes'>
      <image compression='off'/>
    </graphics>
    <sound model='ich6'>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x02' function='0x0'/>
    </sound>
    <video>
      <model type='qxl' ram='65536' vram='65536' vgamem='16384' heads='1'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x0'/>
    </video>
    <hostdev mode='subsystem' type='pci' managed='yes'>
      <source>
        <address domain='0x0000' bus='0x03' slot='0x00' function='0x0'/>
      </source>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x07' function='0x0'/>
    </hostdev>
    <hostdev mode='subsystem' type='pci' managed='yes'>
      <source>
        <address domain='0x0000' bus='0x03' slot='0x00' function='0x1'/>
      </source>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x08' function='0x0'/>
    </hostdev>
    <redirdev bus='usb' type='spicevmc'>
    </redirdev>
    <redirdev bus='usb' type='spicevmc'>
    </redirdev>
    <memballoon model='virtio'>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x09' function='0x0'/>
    </memballoon>
  </devices>
</domain>

To prove I have nested virtualization:

$ cat /sys/module/kvm_intel/parameters/nested
Y

So I really just am at a loss as to what the problem is and how to fix it....

Answer 1

In order to use virtualization options within Windows you need to use the latest QEMU and Libvirt versions. As well, for UEFI you'll also need the latest version of OVMF (Titanocore). Once you've compiled and/or installed the above mentioned software (as needed), you then need the following lines in your XML configuration file for that VM:

<features>
 ...
  <hyperv>
    ...
    <vendor_id state='on' value='something'/>
  </hyperv>
  <kvm>
    <hidden state='on'/>
  </kvm>
 ...
</features>


<cpu mode='host-passthrough' check='none'>
  ...
  <feature policy='disable' name='hypervisor'/>
</cpu>

Now, I am less sure about the vendor_id and kvm hidden state values than I am about the cpu hypervisor feature tag value, but better safe than sorry. This will ensure that:

• Windows doesn't know it's in a hypervisor by being told by the cpu
• Windows won't be able to tell it's within KVM.
• If somehow it manages to figure out it's in a hypervisor, it won't know from what program or company and I believe will simply assume it's in a Windows VM instead of something else.

My technical knowledge on this subject is rather limited, so see the relevant documentation and learn more if you need to.

Answer 2

Try change cpu mode to "host-passthrough". It should work, but afraid you will run into other errors, like "Microsoft Hyper-V Virtual Machine Bus Provider" errors.