I have an unraid box that previously had a fully functioning usb keyboard and usb mouse passed through with GPU passthrough to a Win 7 VM.  Of course the morning I intended to add another VM with another GPU and keyboard/mouse I had an issue.

 

If I boot it into the unraid GUI mouse and keyboard both function.  When I start the VM then the keyboard stops working and the mouse remains.  I wasn't sure what the problem was so I went ahead and installed the new hardware and now I have two VMs with the same non functioning keyboard inside the VM.  I tried swapping peripherals back and forth and no joy.  Is it a virtIO driver problem or something like that?  Any suggestions what to try next?

So I was able to get one VM working by manually editing the XML by changing:

 

Each usb device I selected in the GUI edit from:

<hostdev mode='subsystem' type='usb' managed='no'>

 

To this:

<hostdev mode='subsystem' type='usb' managed='yes'>

 

I did the same thing on the other VM and the mouse worked and it seemed like the keyboard wasn't working and then I think I discovered it was still attached to the host.  Because when I randomly did ctrl+alt+del it rebooted the whole unraid box.

My XML for the VM that will still not pass the keyboard.

 

<domain type='kvm'>
  <name>Windows 7 - Luke</name>
  <uuid>c6a2da56-bdea-3c35-ff60-196b168543ba</uuid>
  <metadata>
    <vmtemplate xmlns="unraid" name="Windows 7" icon="windows7.png" os="windows7"/>
  </metadata>
  <memory unit='KiB'>2097152</memory>
  <currentMemory unit='KiB'>2097152</currentMemory>
  <memoryBacking>
    <nosharepages/>
  </memoryBacking>
  <vcpu placement='static'>4</vcpu>
  <cputune>
    <vcpupin vcpu='0' cpuset='0'/>
    <vcpupin vcpu='1' cpuset='1'/>
    <vcpupin vcpu='2' cpuset='2'/>
    <vcpupin vcpu='3' cpuset='3'/>
  </cputune>
  <os>
    <type arch='x86_64' machine='pc-i440fx-1.4'>hvm</type>
  </os>
  <features>
    <acpi/>
    <apic/>
    <hyperv>
      <relaxed state='on'/>
      <vapic state='on'/>
      <spinlocks state='on' retries='8191'/>
      <vendor_id state='on' value='none'/>
    </hyperv>
  </features>
  <cpu mode='host-passthrough'>
    <topology sockets='1' cores='2' threads='2'/>
  </cpu>
  <clock offset='localtime'>
    <timer name='hypervclock' present='yes'/>
    <timer name='hpet' present='no'/>
  </clock>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>restart</on_crash>
  <devices>
    <emulator>/usr/local/sbin/qemu</emulator>
    <disk type='file' device='disk'>
      <driver name='qemu' type='raw' cache='writeback'/>
      <source file='/mnt/user/domains/Windows 7 - Luke/vdisk1.img'/>
      <target dev='hdc' bus='virtio'/>
      <boot order='1'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
    </disk>
    <disk type='file' device='cdrom'>
      <driver name='qemu' type='raw'/>
      <source file='/mnt/user/isos/Win 7 Pro 64 DVD.iso'/>
      <target dev='hda' bus='ide'/>
      <readonly/>
      <boot order='2'/>
      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
    </disk>
    <disk type='file' device='cdrom'>
      <driver name='qemu' type='raw'/>
      <source file='/mnt/user/isos/virtio-win-0.1.126-2.iso'/>
      <target dev='hdb' bus='ide'/>
      <readonly/>
      <address type='drive' controller='0' bus='0' target='0' unit='1'/>
    </disk>
    <controller type='usb' index='0' model='ich9-ehci1'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x7'/>
    </controller>
    <controller type='usb' index='0' model='ich9-uhci1'>
      <master startport='0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0' multifunction='on'/>
    </controller>
    <controller type='usb' index='0' model='ich9-uhci2'>
      <master startport='2'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x1'/>
    </controller>
    <controller type='usb' index='0' model='ich9-uhci3'>
      <master startport='4'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x2'/>
    </controller>
    <controller type='pci' index='0' model='pci-root'/>
    <controller type='ide' index='0'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
    </controller>
    <controller type='virtio-serial' index='0'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </controller>
    <interface type='bridge'>
      <mac address='52:54:00:3c:46:4b'/>
      <source bridge='br0'/>
      <model type='virtio'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
    </interface>
    <serial type='pty'>
      <target port='0'/>
    </serial>
    <console type='pty'>
      <target type='serial' port='0'/>
    </console>
    <channel type='unix'>
      <target type='virtio' name='org.qemu.guest_agent.0'/>
      <address type='virtio-serial' controller='0' bus='0' port='1'/>
    </channel>
    <input type='mouse' bus='ps2'/>
    <input type='keyboard' bus='ps2'/>
    <hostdev mode='subsystem' type='pci' managed='yes' xvga='yes'>
      <driver name='vfio'/>
      <source>
        <address domain='0x0000' bus='0x05' slot='0x00' function='0x0'/>
      </source>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
    </hostdev>
    <hostdev mode='subsystem' type='usb' managed='no'>
      <source>
        <vendor id='0x04f2'/>
        <product id='0x0833'/>
      </source>
      <address type='usb' bus='0' port='1'/>
    </hostdev>
    <hostdev mode='subsystem' type='usb' managed='no'>
      <source>
        <vendor id='0x1bcf'/>
        <product id='0x0007'/>
      </source>
      <address type='usb' bus='0' port='2'/>
    </hostdev>
    <memballoon model='virtio'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
    </memballoon>
  </devices>
</domain>