Whenever I start my VM my syslog on unraid get's spammed with

 

Feb  1 14:58:50 Tower kernel: usb 1-3.4: usbfs: usb_submit_urb returned -28

 

tons of these, like 10 a second.

 

Here's my VM config:

 

<domain type='kvm' id='2' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>
  <name>Media</name>
  <uuid>d8070111-f188-78ce-cfdb-dcdd7f271bea</uuid>
  <metadata>
    <snapshot1422724253>All Installed, Base Kodi</snapshot1422724253>
    <snapshot1422717187>Drivers Installed</snapshot1422717187>
    <snapshots/>
  </metadata>
  <memory unit='KiB'>6291456</memory>
  <currentMemory unit='KiB'>6291456</currentMemory>
  <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>
  <resource>
    <partition>/machine</partition>
  </resource>
  <os>
    <type arch='x86_64' machine='pc-q35-2.1'>hvm</type>
    <loader>/usr/share/qemu/bios-256k.bin</loader>
    <boot dev='cdrom'/>
  </os>
  <features>
    <acpi/>
    <apic/>
  </features>
  <cpu mode='host-passthrough'>
  </cpu>
  <clock offset='localtime'>
    <timer name='rtc' tickpolicy='catchup'/>
    <timer name='pit' tickpolicy='delay'/>
    <timer name='hpet' present='yes'/>
    <timer name='hypervclock' present='yes'/>
  </clock>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>destroy</on_crash>
  <pm>
    <suspend-to-mem enabled='no'/>
    <suspend-to-disk enabled='no'/>
  </pm>
  <devices>
    <emulator>/usr/bin/qemu-system-x86_64</emulator>
    <disk type='file' device='disk'>
      <driver name='qemu' type='qcow2' cache='none' io='native'/>
      <source file='/mnt/cache/vm/Media/Media.qcow2'/>
      <backingStore/>
      <target dev='hda' bus='virtio'/>
      <alias name='virtio-disk0'/>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x04' function='0x0'/>
    </disk>
    <controller type='pci' index='0' model='pcie-root'>
      <alias name='pcie.0'/>
    </controller>
    <controller type='pci' index='1' model='dmi-to-pci-bridge'>
      <alias name='pci.1'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x1e' function='0x0'/>
    </controller>
    <controller type='pci' index='2' model='pci-bridge'>
      <alias name='pci.2'/>
      <address type='pci' domain='0x0000' bus='0x01' slot='0x01' function='0x0'/>
    </controller>
    <controller type='sata' index='0'>
      <alias name='sata0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x1f' function='0x2'/>
    </controller>
    <controller type='virtio-serial' index='0'>
      <alias name='virtio-serial0'/>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x02' function='0x0'/>
    </controller>
    <controller type='usb' index='0' model='ich9-ehci1'>
      <alias name='usb0'/>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x03' function='0x7'/>
    </controller>
    <controller type='usb' index='0' model='ich9-uhci1'>
      <alias name='usb0'/>
      <master startport='0'/>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x03' function='0x0' multifunction='on'/>
    </controller>
    <controller type='usb' index='0' model='ich9-uhci2'>
      <alias name='usb0'/>
      <master startport='2'/>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x03' function='0x1'/>
    </controller>
    <controller type='usb' index='0' model='ich9-uhci3'>
      <alias name='usb0'/>
      <master startport='4'/>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x03' function='0x2'/>
    </controller>
    <controller type='ide' index='0'>
      <alias name='ide0'/>
    </controller>
    <interface type='bridge'>
      <mac address='52:54:00:46:29:be'/>
      <source bridge='br0'/>
      <target dev='vnet0'/>
      <model type='virtio'/>
      <alias name='net0'/>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x01' function='0x0'/>
    </interface>
    <hostdev mode='subsystem' type='usb' managed='no'>
      <source>
        <vendor id='0x150a'/>
        <product id='0x1203'/>
        <address bus='1' device='6'/>
      </source>
      <alias name='hostdev0'/>
    </hostdev>
    <hostdev mode='subsystem' type='usb' managed='no'>
      <source>
        <vendor id='0x045e'/>
        <product id='0x0719'/>
        <address bus='1' device='7'/>
      </source>
      <alias name='hostdev1'/>
    </hostdev>
    <hostdev mode='subsystem' type='usb' managed='no'>
      <source>
        <vendor id='0x0403'/>
        <product id='0x6001'/>
        <address bus='1' device='5'/>
      </source>
      <alias name='hostdev2'/>
    </hostdev>
    <hostdev mode='subsystem' type='usb' managed='no'>
      <source>
        <vendor id='0x046d'/>
        <product id='0xc52b'/>
        <address bus='1' device='4'/>
      </source>
      <alias name='hostdev3'/>
    </hostdev>
    <hostdev mode='subsystem' type='usb' managed='no'>
      <source>
        <vendor id='0x0424'/>
        <product id='0x2507'/>
        <address bus='1' device='3'/>
      </source>
      <alias name='hostdev4'/>
    </hostdev>
    <memballoon model='virtio'>
      <alias name='balloon0'/>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x05' function='0x0'/>
    </memballoon>
  </devices>
  <qemu:commandline>
    <qemu:arg value='-device'/>
    <qemu:arg value='ioh3420,bus=pcie.0,addr=1c.0,multifunction=on,port=1,chassis=1,id=root.1'/>
    <qemu:arg value='-device'/>
    <qemu:arg value='vfio-pci,host=02:00.0,bus=root.1,addr=00.0,multifunction=on,x-vga=on'/>
    <qemu:arg value='-device'/>
    <qemu:arg value='vfio-pci,host=02:00.1,bus=pcie.0'/>
  </qemu:commandline>
</domain>

I would start by removing each usb device and see which one is causing this.  You can paste this xml as a new vm just change the uuid by one and the name.

I just passed through the entire usb bus instead.