[vfio-users] No HDMI audio from AMD RX480 when passed through to Windows 8.1 VM.

[Luke Yelavich]

Greetings.
I'm writing with a rather annoying problem. I am unable to get audio output through HDMI on an AMD RX480 card that is being passed through to a Windows 8.1 VM.

I am running Fedora 25 with all updates applied as of today, 18 January 2017. I am using libvirt with qemu/KVM, and I am using virt-manager to set things up. The graphics card itself works fine once the AMD drivers are installed.

I was reading through the list archives, and noticed that someone else had a similar suggestion. One suggestion I remember trying in that thread was to configure the HDMI audio device as a sub-device of the main graphics card, but that doesn't seem to have helped. You will notice that change in the XML pasted below.

One other thing that was asked in that thread was to provide the output of the domxml-to-native command from virsh. In attempting to run that command, I get
error: internal error: invalid PCI passthrough type 'default'

Any help is much appreciated, XML is below.

Thanks in advance.

Luke

<domain type='kvm'>
  <name>Win8.1-Pro-64</name>
  <uuid>fc91d936-dbfb-4ddc-a535-752680b969e0</uuid>
  <title>Windows 8.1 Professional 64-bit</title>
  <memory unit='KiB'>16777216</memory>
  <currentMemory unit='KiB'>16777216</currentMemory>
  <vcpu placement='static'>2</vcpu>
  <os>
    <type arch='x86_64' machine='pc-i440fx-2.7'>hvm</type>
    <loader readonly='yes' type='pflash'>/usr/share/edk2/ovmf/OVMF_CODE.fd</loader>
    <nvram>/var/lib/libvirt/qemu/nvram/Win8.1-Pro-64_VARS.fd</nvram>
  </os>
  <features>
    <acpi/>
    <apic/>
    <hyperv>
      <relaxed state='on'/>
      <vapic state='on'/>
      <spinlocks state='on' retries='8191'/>
    </hyperv>
    <vmport state='off'/>
  </features>
  <cpu mode='host-passthrough'/>
  <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/qemu-kvm</emulator>
    <disk type='block' device='disk'>
      <driver name='qemu' type='raw' cache='none' io='native'/>
      <source dev='/dev/fedora_balta/Win8.1-Pro-64'/>
      <target dev='sda' bus='scsi'/>
      <boot order='2'/>
      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
    </disk>
    <controller type='usb' index='0' model='ich9-ehci1'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x7'/>
    </controller>
    <controller type='usb' index='0' model='ich9-uhci1'>
      <master startport='0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0' multifunction='on'/>
    </controller>
    <controller type='usb' index='0' model='ich9-uhci2'>
      <master startport='2'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x1'/>
    </controller>
    <controller type='usb' index='0' model='ich9-uhci3'>
      <master startport='4'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x2'/>
    </controller>
    <controller type='scsi' index='0' model='virtio-scsi'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
    </controller>
    <controller type='pci' index='0' model='pci-root'/>
    <interface type='bridge'>
      <mac address='52:54:00:02:48:5f'/>
      <source bridge='bridge0'/>
      <model type='rtl8139'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </interface>
    <input type='mouse' bus='ps2'/>
    <input type='keyboard' bus='ps2'/>
    <hostdev mode='subsystem' type='pci' managed='yes'>
      <source>
        <address domain='0x0000' bus='0x03' slot='0x00' function='0x0'/>
      </source>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x09' function='0x0' multifunction='on'/>
    </hostdev>
    <hostdev mode='subsystem' type='pci' managed='yes'>
      <source>
        <address domain='0x0000' bus='0x03' slot='0x00' function='0x1'/>
      </source>
      <rom bar='off'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x09' function='0x1'/>
    </hostdev>
    <hostdev mode='subsystem' type='pci' managed='yes'>
      <source>
        <address domain='0x0000' bus='0x00' slot='0x1d' function='0x0'/>
      </source>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
    </hostdev>
    <memballoon model='virtio'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/>
    </memballoon>
  </devices>
</domain>