Card B50 pro

Fedora 44 with Q35/i440 dedicated GPU works as expected. Sound passed thro show in lspci but not detected by OS.

Win11 with Q35/i440 dedicated GPU works as expected Sound passed thro standard MS driver. sound not detected by OS

Win11 with Q35/i440 Virtual + dedicated GPU works as expected Sound passed thro Latest Intel drivers sound not detected by OS

Arc770

Win11 with Q35 dedicated and with virtual work. System still crashes if Audio is passed thru. Without Audio works as expected.

Ubuntu working with i440, Q35 did not initialise the ARC 770. Working as expected without audio.

Fedora 44 with i440 dedicated GPU works as expected. No Audio passthru

Found linux does not seem to like Q35 for ARC A cards.

Q35 10.2 and I440 10.2 used in vms on 7.3.2

Thanks for looking into this!

I am running Garuda Linux Hyprland (Arch Linux based).

Machine: Q35-9.2

GPU: Intel ARC A380

1 hour ago, SimonF said:

Can you provide details of Machine setups.

I.e. Q35 of i400fx

Gpu models

I am testing to see if I can find an issue. I have a A770 and B50Pro to test with,

Starting with Win11 A770

In my case it's an EndevourOS guest with Q35 and and an Arc B580 - one of the Intel Limited Edition cards in case that might make some difference.
And then for info the other things that might matter is it's a an MSI MAG B760M Motherboard paired with an i5-13400.

I've never gotten audio from it to work on any version of Unraid but then have never tried very hard to and in terms of video I could see and choose a kernel with systemd-boot, but then as it was whizzing through Text-Mode Boot the display would blank and put the 'failed to map registers' and 'probe with driver xe failed' errors in the syslog as I noted previously.

Is the GPU the primary gpu in your systems? Below will be 1 if primary. You may need a boot rom if it is primary.

cat /sys/bus/pci/devices/pciid/boot_vga

root@QNAPR420:~# lspci | grep VGA

00:02.0 VGA compatible controller: Intel Corporation Arrow Lake-S [Intel Graphics] (rev 06)

04:00.0 VGA compatible controller: Intel Corporation DG2 [Arc A770] (rev 08)

80:14.5 Non-VGA unclassified device: Intel Corporation Device 7f2f (rev 10)

root@QNAPR420:~#

root@QNAPR420:~# cat /sys/bus/pci/devices/0000\:00\:02.0/boot_vga

1

root@QNAPR420:~# cat /sys/bus/pci/devices/0000\:04\:00.0/boot_vga

0

root@QNAPR420:~#

On 7/11/2026 at 10:14 AM, Ver7o said:

7.3.2 with A310 and CachyOS. Video works, audio does not.

7.3.2 with B50 and CachyOS. Video works, audio does not.

Sparkle A310 Omni view

Intel B50

both cases Q35 and OVMF. both times dGPU is not set as primary.

both times the audio is passed through, lspci detects it withing vm, but driver only lists analogue capabilites hence the no HDMI sound.

root@Tower:~# lspci | grep VGA

03:00.0 VGA compatible controller: Intel Corporation DG2 [Arc A380] (rev 05)

root@Tower:~# cat /sys/bus/pci/devices/0000\:03\:00.0/boot_vga

0

Garuda Linux Hyprland (Arch Linux based).

Machine: Q35-9.2

Bios: OVMF

GPU: Intel ARC A380

root@Tower:~# lspci | grep VGA

03:00.0 VGA compatible controller: Intel Corporation DG2 [Arc A380] (rev 05)

15:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Granite Ridge [Radeon Graphics] (rev d1)

root@Tower:~# cat /sys/bus/pci/devices/0000\:03\:00.0/boot_vga

0

root@Tower:~# cat /sys/bus/pci/devices/0000\:15\:00.0/boot_vga

1

My findings here.

Upgraded to 7.2.8, unfortunately this breaks Intel Arc GPU passthrough.

I created a new VM with i440fx-10.2 and attached the HDD file to it (simply changing the existing VM from Q35 to i440fx resulted in an XML pci error)

This worked. So I decided to upgrade to 7.3.2 with the VM running i440fx and it works fine.

i440fx is an undesirable downgrade from Q35, but at least things are working with it.

Any Updates here?

I also use UNRAID 7.3.2. My Windows VMs are working just fine with my NVIDIA RTX 5060Ti in an Occulink setup. But all combinations to boot up an Linux (Debian) VM with gpu passthrought just gets a black screen... nothing else!

Any help here? Thanks P.

27 minutes ago, csuno said:

Any Updates here?

I also use UNRAID 7.3.2. My Windows VMs are working just fine with my NVIDIA RTX 5060Ti in an Occulink setup. But all combinations to boot up an Linux (Debian) VM with gpu passthrought just gets a black screen... nothing else!

Any help here? Thanks P.

My solution should get the VM working for you. Although it's definitely to be considered a downgrade as i440fx vs Q35 has introduced a lot of stuttering and system hanging for me when things are happening on host.

Try to create a new VM (i440fx) and mount the intended HDD vdisk, see if that gets you further than the blank screen.

Hopefully the Q35 issue will get resolved. There's nothing worse than having to compromise on newer software something that was working flawlessly on older.

Is this still an issue? I skipped 7.3.2 because I need my VM guests at full performance. With 7.3.3 out now, there are some improvements I want on the host, but can't afford to roll back to i440fx.

On 10/9/2026 at 3:23 PM, airtower said:

Is this still an issue? I skipped 7.3.2 because I need my VM guests at full performance. With 7.3.3 out now, there are some improvements I want on the host, but can't afford to roll back to i440fx.

7.3.3 hasn't fixed anything. Same issue persists.

I've been having this problem on my Intel Arc A750 since trying to upgrade from 7.2.4 and it was driving me crazy.
Gave it another swing today, asking ChatGPT to come up with ideas and "we" managed to fix it.

Here's what it came up with (more info on my system below) :

1. Shut down VM

2. Edit > XML View

3. Change the <domain> tag and add an entry before the final </domain> tag (see code below)

4. Start VM and enjoy GPU passthrough

Here's the code - At the very beginning I changed the <domain ...> tag to:

<domain type='kvm' id='2' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>

At the very end, just before the final </domain> tag, I added:

<qemu:commandline>
  <qemu:arg value='-global'/>
  <qemu:arg value='pcie-root-port.mem-reserve=32M'/>
</qemu:commandline>

Some more info:

My configuration:

• Unraid 7.3.3 (upgrading from 7.2.4)

• Intel Arc A750 (GPU and audio passed through)

• Bazzite Linux

• Q35 9.2 with OVMF

• GPU assigned to a dedicated PCIe root port

After upgrading, the VM would boot, but the GPU failed to initialize properly. The Bazzite kernel logs showed PCIe BAR allocation errors:

BAR 0: can't claim; no compatible bridge window

BAR 0: can't assign; no space

BAR 0: failed to assign

The GPU required a 16 MiB non-prefetchable memory region, but the PCIe root port only had a 2 MiB memory window.

After restarting the VM, the GPU's BAR 0 was successfully allocated at 0x82000000, the Intel i915 driver initialized correctly, and the GPU firmware loaded successfully.

The initial can't claim message still appears, but Linux subsequently reallocates the BAR successfully.

The can't assign; no space and failed to assign errors are gone.

Everything appears to be working normally now, including GPU initialization, while retaining Q35.

Did this solve both the audio passthrough and the blanks screen bug in 7.3.2+?

I couldn't use my GPU at all before this and now I can run Docker containers inside Bazzite that have access to my Intel Arc GPU and I can use Sunshine to stream Steam games to any device that can run Moonlight. So my remote desktop is working and I just tried playing a YouTube video, sound was passed through as well. Everything I could do with my Bazzite VM on 7.2.4 and that stopped working in later Unraid versions is now working again.

This fix works for me. I updated a new Omarchy Quattro (Arch linux/Hyprland) VM with the XML edits and tried booting before doing the update. It worked without issues, so I updated Unraid from 7.2.7 to 7.3.4. I then booted the VM and again didn't see any issues. Audio and video works normally. I then remembered I posted that my issue was on a Garuda Linux Hyprland (Arch Linux based) VM. Since I hadn't used it in awhile, I went ahead and did the XML edits on it also and booted it up. It also works without issues. Thank you for the fix!

Edited October 22Oct 22 by Kinspappy

56 minutes ago, Kinspappy said:

This fix works for me. I updated a new Omarchy Quattro (Arch linux/Hyprland) VM with the XML edits and tried booting before doing the update. It worked without issues, so I updated Unraid from 7.2.7 to 7.3.4. I then booted the VM and again didn't see any issues. Audio and video works normally. I then remembered I posted that my issue was on a Garuda Linux Hyprland (Arch Linux based) VM. Since I hadn't used it in awhile, I went ahead and did the XML edits on it also and booted it up. It also works without issues. Thank you for the fix!

Glad to hear it, I guess most of the kudos goes to ChatGPT digging up this forum entry and applying it to our problem (and of course to @ledemon who posted the fix first). I only just checked where the bot got its information from, most of the time there's so much trial and error involved with troubleshooting that I hardly ever bother to look where the ideas came from, if the bot even lets me know. Anyway, hope this will fix it for most of us. I had been checking this thread here every time a new Unraid update hit only to see things hadn't really changed - let's hope this problem is gone for good now.

Confirmed, back on Q35. Great work @dnaKID

Saw all the positive response and jumped form 7.2.7 to 7.3.4 and can confirm dnaKID's fix worked on an Arc B580.

Q35, cachy linux, arc pro b50.

I never had black screen issues, only audio passthrough not working. And with these edits I'm sad to report, the audio still doesnt initialize correctly (dummy output only).

I'm really happy for people who got it working with this. Kudos @dnaKID .

Was this ever an issue for Windows guests? I know the thread title says Linux, but the 7.3.3 release notes was ambiguous with regard to OS type and referenced this thread. I finally got around to upgrading from 7.3.1 and my Win 11 VM started just fine. I have made many xml tweaks in the interest of performance tuning with the help of Claude, but not the exact change called out in the solution post. I really don't know if I fixed/avoided the issue in some other way, or if it was never a Windows issue.

I may see if this fixes audio passthrough, but I recall hearing that worked on Linux VMs previously before breaking. So I feel like there's a bigger issue with audio passthrough on Windows guests.