Hello everyone,

I'm setting up a gaming VM on my Unraid server and facing a boot issue after installing a new GPU.

Hardware Configuration:

• Motherboard: Gigabyte H410M H V3

• CPU: Intel Core i5-10400

• RAM: 32GB

• New GPU (for VM Passthrough): AMD Radeon RX 6600 (ASRock Challenger D)

• PSU: Corsair CV550

The Problem:

1. VT-d Disabled: If I leave Intel VT-d (IOMMU) disabled in the BIOS, Unraid boots perfectly fine to the Web GUI.

2. VT-d Enabled: If I enable Intel VT-d (IOMMU) in the BIOS (required for proper Passthrough), the Unraid boot sequence stops and freezes at the following message:Exiting up to 30 sec for device with BOOT UNRAID to come online (you can check more details on the attatched image)

Question:

How to solve this? I never did a GPU Passthrough before so I might be missing something.

Thank you very much!

Test with a new flash drive using a tock install; no key is needed, if it still happens, it suggests a hardware compatibility issue with the kernel; look for a BIOS update.

@JorgeB the bios updated did work. I was able to boot with the VT-d option on but had to change syslinux.cfg:

root@Musashi:~# cat /boot/syslinux/syslinux.cfg
default menu.c32
menu title Lime Technology, Inc.
prompt 0
timeout 50
label Unraid OS
  menu default
  kernel /bzimage
  append initrd=/bzroot vfio-pci.ids=1002:73ff,1002:ab28
label Unraid OS GUI Mode
  kernel /bzimage
  append initrd=/bzroot,/bzroot-gui
label Unraid OS Safe Mode (no plugins, no GUI)
  kernel /bzimage
  append initrd=/bzroot unraidsafemode
label Unraid OS GUI Safe Mode (no plugins)
  kernel /bzimage
  append initrd=/bzroot,/bzroot-gui unraidsafemode
label Memtest86+
  kernel /memtest

Also, I had to enable a option on the BIOS to use integrated cpu graphics as primary card. This way, when I boot the server it uses my CPU graphics and leaves the AMD GPU to VMs. Original problem solved.

My issue now is that, for some reason, I cant start my VM with AMD GPU on passthru mode. I got the error "Start disabled due to PCI chagnes". My current VM setup is the following:

<?xml version='1.0' encoding='UTF-8'?>
<domain type='kvm'>
  <name>Windows 11</name>
  <uuid>d433efed-5a60-cfa1-3ecb-459ac53e0fd0</uuid>
  <metadata>
    <vmtemplate xmlns="unraid" name="Windows 11" iconold="windows11.png" icon="windows11.png" os="windowstpm" webui="" storage="default"/>
  </metadata>
  <memory unit='KiB'>25165824</memory>
  <currentMemory unit='KiB'>25165824</currentMemory>
  <memoryBacking>
    <nosharepages/>
  </memoryBacking>
  <vcpu placement='static'>6</vcpu>
  <cputune>
    <vcpupin vcpu='0' cpuset='0'/>
    <vcpupin vcpu='1' cpuset='1'/>
    <vcpupin vcpu='2' cpuset='2'/>
    <vcpupin vcpu='3' cpuset='3'/>
    <vcpupin vcpu='4' cpuset='4'/>
    <vcpupin vcpu='5' cpuset='5'/>
  </cputune>
  <os>
    <type arch='x86_64' machine='pc-q35-9.2'>hvm</type>
    <loader readonly='yes' type='pflash' format='raw'>/usr/share/qemu/ovmf-x64/OVMF_CODE-pure-efi.fd</loader>
    <nvram format='raw'>/etc/libvirt/qemu/nvram/d433efed-5a60-cfa1-3ecb-459ac53e0fd0_VARS-pure-efi.fd</nvram>
  </os>
  <features>
    <acpi/>
    <apic/>
    <hyperv mode='custom'>
      <relaxed state='on'/>
      <vapic state='on'/>
      <spinlocks state='on' retries='8191'/>
      <vpindex state='on'/>
      <synic state='on'/>
      <stimer state='on'/>
      <vendor_id state='on' value='none'/>
    </hyperv>
  </features>
  <cpu mode='host-passthrough' check='none' migratable='on'>
    <topology sockets='1' dies='1' clusters='1' cores='3' threads='2'/>
    <cache mode='passthrough'/>
  </cpu>
  <clock offset='localtime'>
    <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>
  <devices>
    <emulator>/usr/local/sbin/qemu</emulator>
    <disk type='file' device='disk'>
      <driver name='qemu' type='raw' cache='writeback' discard='unmap'/>
      <source file='/mnt/user/domains/Windows 11/vdisk1.img'/>
      <target dev='hdc' bus='virtio'/>
      <serial>vdisk1</serial>
      <boot order='1'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
    </disk>
    <disk type='file' device='cdrom'>
      <driver name='qemu' type='raw'/>
      <source file='/mnt/user/isos/Win11_25H2_English_x64.iso'/>
      <target dev='hda' bus='sata'/>
      <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-0.1.285.iso'/>
      <target dev='hdb' bus='sata'/>
      <readonly/>
      <address type='drive' controller='0' bus='0' target='0' unit='1'/>
    </disk>
    <controller type='pci' index='0' model='pcie-root'/>
    <controller type='pci' index='1' model='pcie-root-port'>
      <model name='pcie-root-port'/>
      <target chassis='1' port='0x8'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x0' multifunction='on'/>
    </controller>
    <controller type='pci' index='2' model='pcie-root-port'>
      <model name='pcie-root-port'/>
      <target chassis='2' port='0x9'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
    </controller>
    <controller type='pci' index='3' model='pcie-root-port'>
      <model name='pcie-root-port'/>
      <target chassis='3' port='0xa'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
    </controller>
    <controller type='pci' index='4' model='pcie-root-port'>
      <model name='pcie-root-port'/>
      <target chassis='4' port='0xb'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x3'/>
    </controller>
    <controller type='pci' index='5' model='pcie-root-port'>
      <model name='pcie-root-port'/>
      <target chassis='5' port='0xc'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x4'/>
    </controller>
    <controller type='pci' index='6' model='pcie-root-port'>
      <model name='pcie-root-port'/>
      <target chassis='6' port='0xd'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x5'/>
    </controller>
    <controller type='pci' index='7' model='pcie-to-pci-bridge'>
      <model name='pcie-pci-bridge'/>
      <address type='pci' domain='0x0000' bus='0x01' slot='0x00' function='0x0'/>
    </controller>
    <controller type='virtio-serial' index='0'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
    </controller>
    <controller type='usb' index='0' model='ich9-ehci1'>
      <address type='pci' domain='0x0000' bus='0x07' slot='0x01' function='0x7'/>
    </controller>
    <controller type='sata' index='0'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x1f' function='0x2'/>
    </controller>
    <interface type='bridge'>
      <mac address='52:54:00:60:a5:ae'/>
      <source bridge='br0'/>
      <model type='e1000'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
    </interface>
    <serial type='pty'>
      <target type='isa-serial' port='0'>
        <model name='isa-serial'/>
      </target>
    </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'/>
    <audio id='1' type='none'/>
    <hostdev mode='subsystem' type='pci' managed='yes'>
      <driver name='vfio'/>
      <source>
        <address domain='0x0000' bus='0x03' slot='0x00' function='0x0'/>
      </source>
      <rom file='/boot/config/vbios/rx6600-vbios.rom'/>
      <address type='pci' domain='0x0000' bus='0x05' slot='0x00' function='0x0' multifunction='on'/>
    </hostdev>
    <hostdev mode='subsystem' type='pci' managed='yes'>
      <driver name='vfio'/>
      <source>
        <address domain='0x0000' bus='0x03' slot='0x00' function='0x1'/>
      </source>
      <address type='pci' domain='0x0000' bus='0x05' slot='0x00' function='0x1'/>
    </hostdev>
    <watchdog model='itco' action='reset'/>
    <memballoon model='none'/>
  </devices>
</domain>

Edited December 5, 2025Dec 5 by feam

8 hours ago, feam said:

"Start disabled due to PCI chagnes"

You need to recheck the devices being passed through; since they changed, you can also acknowledge them if they are correct.

3 hours ago, JorgeB said:

You need to recheck the devices being passed through; since they changed, you can also acknowledge them if they are correct.

@JorgeB They seem correct to me:

Graphics Card: AMD Radeon RX 6600/6600 XT/6600M (03:00.0)
Sound Card: AMD Navi 21/23 HDMI/DP Audio Controller (03:00.1)
Graphics ROM BIOS: /boot/config/vbios/rx6600-vbios.rom

how do I acknowledge this?

There should be a button on Tools - System Devices to acknowledge the changes if the warning is coming from there.

@JorgeB thank you very much. After acknowledge the warnings everything went good.

Appreciated.