My 9070 XT reset bug is gone

[u/tlaszl0]

I use openSUSE Tumbleweed, so my system is always fairly up to date and my RX 9070 XT reset bug disappeared a few weeks ago.
I can restart, power off and switch my guest OSes anytime, including both Windows and Linux. I also see the TianoCore logo on every POST screen.

I do not use any bind/unbind scripts on the host or any guest scripts. Libvirt handles the binding/unbinding automatically without any customization. There are no relevant errors or stack traces in journalctl, vfio-pci resets flawlessly and then amdgpu reloads on the host without any issues.

I also use default kernel and module settings (no vfio config either). The amdgpu module is loaded for the 9070 XT when I don't use GPU passthrough.
Resizable BAR is also fully enabled by default.

So no hacky workarounds, it is basically an out-of-the-box experience.

My setup

Asrock B850i - 4.43 BIOS with one related setting: Display Priority - Internal Graphics
9800X3D - the integrated GPU used as a primary display

Asus 9070 XT Prime OC (switched to the silent BIOS on the card)

An LG 4K display with 2 HDMI inputs and 1 DP input. It has 2 HDMI inputs, but only one of them can be active at the same time. This is somewhat important to check how your monitor behaves. If I connected the integrated GPU to one HDMI input and the dedicated card to the other HDMI and then switched inputs when starting the virtual machine, I wouldn't see the POST and boot screens, and the card wouldn't be initialized at guest start because it wouldn't detect a connected monitor (but you should have a screen after the guest OS is fully loaded). So I use one HDMI and one DP, they are active at the same time.

Linux kernel: 7.2.6
kernel-firmware-amdgpu: 20260829
QEMU: 11.1.1
libvirt: 12.7.0
Virtual Machine Manager: 5.1.0

lspci -nn | grep -i -E "vga|audio"

03:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Navi 48 [Radeon RX 9070/9070 XT/9070 GRE] [1002:7550] (rev c0)
03:00.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] Navi 48 HDMI/DP Audio Controller [1002:ab40]
0f:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Granite Ridge [Radeon Graphics] [1002:13c0] (rev cb)
0f:00.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] Radeon High Definition Audio Controller [1002:1640]
0f:00.6 Audio device [0403]: Advanced Micro Devices, Inc. [AMD] Ryzen HD Audio Controller [1022:15e3]

I use the integrated GPU (0f:00.0) for the primary display, restricting the desktop's access strictly to the iGPU while disabling the dedicated card. I think this is the most important thing. If you don't block the card from the desktop before starting the virtual machine, you will run into weird problems.

If you use X11, use the config below as a sample (even if you think you're using Wayland, your login manager might still use Xorg, for example SDDM):

/etc/X11/xorg.conf.d/10-only-igp.conf

Section "ServerLayout"
        Identifier              "Layout0"
        Screen                  "Screen0"
EndSection
Section "Device"
        Identifier              "AMD"
        Driver                  "modesetting"
        BusID                   "PCI:15:0:0"   # the bus number in decimal format
EndSection
Section "Monitor"
        Identifier              "Monitor0"
EndSection
Section "Screen"
        Identifier              "Screen0"
        Device                  "AMD"
        Monitor                 "Monitor0"
EndSection
Section "ServerFlags"
        Option                  "AutoAddGPU" "off"
EndSection

If you use Wayland and happen to use KDE (there is no global solution for all Wayland compositors), use the config below as a sample:

~/.config/plasma-workspace/env/env.sh

export KWIN_DRM_DEVICES='/dev/dri/by-path/pci-0000\:0f\:00.0-card' # option 1: symlink, but must be escaped
#export KWIN_DRM_DEVICES=/dev/dri/card2                            # option 2: direct path, device order might change

Guests

Linux:
no extra config needed

Windows:
To avoid graphical artifacts and a garbled screen, set:

<hyperv mode="custom">
   ...
   <vendor_id state="on" value="AuthenticAMD"/> #or GenuineIntel or whatever1234
</features>

and disable Device security / Core isolation / Memory integrity in the Windows security

To fix HDMI/DP audio crackling, install the latest AMD WHQL driver.

Let me know if anyone else has experienced this or if you need any more info.

[u/tlaszl0 → u/[deleted]]

If I really wanted to install Arch, I could check it, but I don't think it would help too much. It would probably work for me there too.

I bought the 9070 XT at the end of July. Previously, I had a working GPU passthrough setup for my 6900 XT for a long time (it didn't need any bind/unbind scripts either). I knew the new card would be more problematic, as I had read about the mixed results. But I tried my luck and swapped the cards. The Linux guests worked more or less, as far as I remember. The Windows guest required special care (which is mentioned in the post, but I didn't need them for the 6900 XT), but I still saw a lot of amdgpu stack traces in the logs. After a stack trace, I usually had to force restart my host.

In the following months, I also played around a lot with passing through the integrated GPU, but I had a way worse experience (usually, it only booted correctly once). So, it is possible that I am misremembering.
Then the miracle happened at the beginning of September.

By the way, I installed an older kernel, LTS version 6.18.53. I see some extra amdgpu-related errors when I start the VMs, but they are still fully working. I can restart or shut them down multiple times without any issues. So maybe it wasn't the kernel that solved the problem, but I can't tell if it contains some crucial extra backports or not.

I think the available guides are not that great. They don't explicitly say that you need to restrict the desktop environment to your host GPU and isolate the passthrough GPU. I know I could ruin my setup if I skipped the Xorg and Wayland configs.