Single-GPU Passthrough: AMD RX 9070 XT (Navi 48 / RDNA 4) on CachyOS

Battle-tested config for passing through a Sapphire Pulse RX 9070 XT to a Windows 10/11 guest on a single-GPU, no-iGPU system. Everything below was debugged across dozens of reboots — if it says "don't do X," someone already tried it and got burned.

Hardware


CPU	AMD Ryzen 5 5600X (Zen 3, no iGPU)
GPU	AMD Radeon RX 9070 XT (Navi 48, RDNA 4) — `1002:7550` + `1002:ab40`
Board	ASUS ROG STRIX B550-F GAMING
Host	CachyOS (Arch-based), kernel `linux-cachyos` 7.0.x
Bootloader	Limine + mkinitcpio
Desktop	KDE Plasma (Wayland) via plasmalogin
Guest	Windows 10/11 on Q35 + OVMF (UEFI)

Key facts about RDNA 4 / Navi 48 passthrough

No reset bug on Navi 48 (unlike RDNA 1-3). The card resets cleanly via PSP on kernel ≥ 6.13.
Do NOT install vendor-reset DKMS. It tops out at RDNA 1 and won't compile on modern kernels.
Do NOT pre-bind the GPU to vfio-pci at boot. Unlike older AMD cards, the 9070 XT must be initialized by amdgpu first. Pre-binding causes the "stuck in D3" error that plagues every forum thread. Let amdgpu own the card at boot, then hand it to vfio-pci at VM start.
Do NOT use disable_idle_d3=1. It makes D3 issues worse on Navi 48, not better.
BAR2 must be resized to 8 MB before binding to vfio-pci. The Windows AMD driver chokes on BAR2 > 8 MB and throws Code 43.

BIOS settings

Setting	Value
SVM Mode	Enabled
IOMMU	Enabled (not Auto)
Above 4G Decoding	Enabled
Re-Size BAR Support	Enabled
CSM	Disabled (UEFI only)

ReBAR + Above 4G are mandatory for the 9070 XT to enumerate its 16 GiB BAR0 cleanly.

1. Kernel cmdline

CachyOS uses Limine. Edit /etc/default/limine, then sudo limine-update.

iommu=pt initcall_blacklist=sysfb_init video=efifb:off pcie_aspm=off pci=noaer

iommu=pt — passthrough mode (lower DMA overhead). On Ryzen with BIOS IOMMU=Enabled, amd_iommu=on is implicit and not needed in the cmdline.
initcall_blacklist=sysfb_init — stops simpledrm from grabbing the GPU early, which blocks the unbind later.
pcie_aspm=off — disables PCIe Active State Power Management; prevents the GPU from entering low-power link states that can interfere with the bind/unbind dance.
pci=noaer — suppresses PCIe Advanced Error Reporting noise during GPU hand-off.
Do NOT add pcie_acs_override unless your IOMMU groups actually need it (check §4 below).

2. Modules and initramfs

`/etc/modprobe.d/kvm.conf`

options kvm_amd nested=1
options kvm     ignore_msrs=1
options kvm     report_ignored_msrs=0

nested=1 — enables nested SVM so the guest can run its own hypervisor (e.g. for RE work). If you don't need nested virt, you can omit this.
ignore_msrs=1 — prevents KVM from injecting #GP on unimplemented MSR accesses (Windows reads many model-specific registers KVM doesn't emulate).

`/etc/mkinitcpio.conf`

MODULES=(vfio_pci vfio vfio_iommu_type1)
HOOKS=(base systemd autodetect microcode kms modconf block keyboard sd-vconsole plymouth filesystems)

The HOOKS line shown here uses systemd-based initramfs (CachyOS default). If you use the traditional busybox hooks, replace systemd/sd-vconsole with udev/consolefont/keymap.

vfio_virqfd was folded into vfio in kernel 5.x. Don't list it.

What NOT to create

Do not create a /etc/modprobe.d/vfio.conf with options vfio-pci ids=1002:7550,1002:ab40. That pre-binds the GPU to vfio at boot, which is exactly what breaks Navi 48. The hookscripts handle the bind/unbind dance.

Rebuild:

sudo mkinitcpio -P
sudo limine-update

3. Required packages

sudo pacman -S qemu-full libvirt virt-manager dnsmasq edk2-ovmf swtpm
sudo systemctl enable --now libvirtd
sudo usermod -aG libvirt,input,kvm "$USER"

4. IOMMU group verification

for d in /sys/kernel/iommu_groups/*/devices/*; do
  n=${d#*/iommu_groups/}; n=${n%%/*}
  printf 'IOMMU Group %s ' "$n"; lspci -nns "${d##*/}"
done | sort -V

You want 1002:7550 (VGA) and 1002:ab40 (HDA) alone or together in a group. CachyOS ships the ACS override patch in the stock kernel if you need it.

5. The D3 problem and how to solve it

This is the core issue everyone hits. The error looks like:

kvm: vfio: Unable to power on device, stuck in D3

What causes it

When amdgpu unbinds from the GPU, the kernel's runtime PM + ACPI drops the card into D3cold within ~1 second. In D3cold, the PCIe config space returns 0xFFFF — the device is electrically powered off. When vfio-pci tries to bind or QEMU tries to access it, it reads 0xFFFF everywhere and reports "stuck in D3."

The fix: lock the GPU in D0 before unbinding

In your start script, before unbinding amdgpu:

echo 0 > /sys/bus/pci/devices/$GPU/d3cold_allowed
echo "on" > /sys/bus/pci/devices/$GPU/power/control

This prevents the kernel from dropping the card into D3cold during the driverless window between amdgpu-unbind and vfio-pci-bind.

Use `managed='no'` on PCI hostdevs

With managed='yes', libvirt's nodedev-detach fires a PM reset (D3hot→D0 cycle) that triggers D3cold on Navi 48. With managed='no', libvirt skips the detach — your script has already bound vfio-pci manually, and QEMU just uses the device as-is.

6. Start script

This runs when the VM starts. It tears down the host desktop, locks the GPU in D0, unbinds amdgpu, resizes BAR2, binds vfio-pci, and starts the VM.

#!/usr/bin/env bash
set -uo pipefail

VGA=$(lspci -D -d 1002:7550 | awk '{print $1}')
HDA=$(lspci -D -d 1002:ab40 | awk '{print $1}')

# 1. Stop the display manager (adapt to your DM: sddm, gdm, plasmalogin, etc.)
if systemctl is-active --quiet plasmalogin.service 2>/dev/null; then
    systemctl stop plasmalogin.service || true
    sleep 1
fi

# 2. Drop VT consoles and framebuffer
for vt in /sys/class/vtconsole/vtcon*/bind; do
    [ -w "$vt" ] && echo 0 > "$vt" 2>/dev/null
done
for d in /sys/bus/platform/drivers/efi-framebuffer/efi-framebuffer.0 \
         /sys/bus/platform/drivers/simple-framebuffer/simple-framebuffer.0; do
    [ -e "$d" ] || continue
    basename "$d" > "$(dirname "$d")/unbind" 2>/dev/null || true
done

# 3. Lock GPU in D0 BEFORE unbinding amdgpu (THE critical step)
echo 0 > /sys/bus/pci/devices/$VGA/d3cold_allowed
echo "on" > /sys/bus/pci/devices/$VGA/power/control

# 4. Unbind amdgpu and snd_hda_intel by PCI address
#    Uses the device's own driver symlink, not the driver's global unbind —
#    avoids races if multiple devices share the same driver.
echo "$VGA" > /sys/bus/pci/devices/$VGA/driver/unbind 2>/dev/null || true
echo "$HDA" > /sys/bus/pci/devices/$HDA/driver/unbind 2>/dev/null || true
sleep 1

# 5. Resize BAR2 to 8 MB (Navi 48 requirement)
echo 3 > /sys/bus/pci/devices/$VGA/resource2_resize

# 6. Bind to vfio-pci manually (managed='no' in XML)
echo vfio-pci > /sys/bus/pci/devices/$VGA/driver_override
echo "$VGA" > /sys/bus/pci/drivers/vfio-pci/bind
echo vfio-pci > /sys/bus/pci/devices/$HDA/driver_override
echo "$HDA" > /sys/bus/pci/drivers/vfio-pci/bind

# 7. (Optional) Hugepages + performance governor
echo 3 > /proc/sys/vm/drop_caches
echo 1 > /proc/sys/vm/compact_memory
echo 8192 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
for c in /sys/devices/system/cpu/cpu*/cpufreq; do
    echo performance > "$c/scaling_governor" 2>/dev/null || true
done

# 8. Start the VM
virsh define /path/to/your-runtime.xml > /dev/null
virsh start win10gaming || exit 1

Important: Do not use modprobe -r amdgpu instead of unbinding by PCI address. If the module is used by anything (console, another GPU), it will refuse. The by-address unbind is the proven path from every working Proxmox/Unraid/Arch setup.

7. Revert script (GPU reclaim on VM shutdown)

This runs when the VM shuts down. The critical detail everyone gets wrong: you must explicitly bind amdgpu by PCI address, not just modprobe amdgpu. The module is already loaded (it drove the console before the VM started), so modprobe is a no-op and the GPU sits driverless.

#!/usr/bin/env bash

VGA=$(lspci -D -d 1002:7550 | awk '{print $1}')
HDA=$(lspci -D -d 1002:ab40 | awk '{print $1}')
UPSTREAM=$(basename "$(readlink -f /sys/bus/pci/devices/$VGA/../)")

gpu_bound() { [ -e /dev/dri/card0 ] || [ -e /dev/dri/card1 ]; }

for attempt in 1 2 3; do
    # Unbind from vfio-pci
    echo "$VGA" > /sys/bus/pci/drivers/vfio-pci/unbind 2>/dev/null || true
    echo "$HDA" > /sys/bus/pci/drivers/vfio-pci/unbind 2>/dev/null || true

    # Clear driver_override (echo "", not ": >" — truncation doesn't trigger the write handler)
    echo "" > /sys/bus/pci/devices/$VGA/driver_override 2>/dev/null || true
    echo "" > /sys/bus/pci/devices/$HDA/driver_override 2>/dev/null || true

    # On retry, do a secondary bus reset via the upstream bridge
    if [ "$attempt" -gt 1 ] && [ -n "$UPSTREAM" ]; then
        cur=$(setpci -s "$UPSTREAM" BRIDGE_CONTROL.w)
        setpci -s "$UPSTREAM" BRIDGE_CONTROL.w=$(printf '%04x' $((0x$cur | 0x40)))
        sleep 1
        setpci -s "$UPSTREAM" BRIDGE_CONTROL.w="$cur"
        sleep 1
    fi

    # Force D0
    setpci -s "${VGA#0000:}" CAP_PM+4.w=0x0000 2>/dev/null || true
    sleep 1

    # Bind amdgpu BY PCI ADDRESS (modprobe alone does nothing)
    modprobe amdgpu 2>/dev/null || true
    echo "$VGA" > /sys/bus/pci/drivers/amdgpu/bind 2>/dev/null || true
    sleep 3

    if gpu_bound; then
        break
    fi
done

# Rebind audio
echo "$HDA" > /sys/bus/pci/drivers/snd_hda_intel/bind 2>/dev/null || true

# Restore VT consoles
for vt in /sys/class/vtconsole/vtcon*; do
    [ -e "$vt/bind" ] && echo 1 > "$vt/bind" 2>/dev/null || true
done

# Restore governor + EPP + free hugepages
for c in /sys/devices/system/cpu/cpu*/cpufreq; do
    echo powersave > "$c/scaling_governor" 2>/dev/null || true
    [ -w "$c/energy_performance_preference" ] && \
        echo balance_performance > "$c/energy_performance_preference" 2>/dev/null || true
done
echo 0 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages 2>/dev/null || true

# Restart display manager only if GPU actually came back
if gpu_bound; then
    systemctl start display-manager.service  # or plasmalogin.service, sddm, gdm, etc.
else
    echo "GPU reclaim failed. SSH in and run reclaim manually, or reboot."
fi

The `driver_override` trap

When the start script sets driver_override=vfio-pci, that value persists after vfio-pci unbinds. If you don't clear it, modprobe amdgpu and even explicit amdgpu/bind writes will be rejected — the kernel routes all probe attempts to vfio-pci because the override is still set.

You must write an empty string to driver_override to clear it:

echo "" > /sys/bus/pci/devices/$VGA/driver_override

Do not use shell truncation (: > file). It truncates the sysfs file to zero bytes but doesn't invoke the kernel's write handler, so the in-memory override value stays set. This is the most subtle bug in the whole setup and the one that cost the most debugging time.

8. VM XML — the important parts

PCI hostdevs — `managed='no'`

<hostdev mode='subsystem' type='pci' managed='no'>
  <driver name='vfio'/>
  <source>
    <address domain='0x0000' bus='0x__' slot='0x00' function='0x0'/>
  </source>
  <address type='pci' domain='0x0000' bus='0x05' slot='0x00' function='0x0' multifunction='on'/>
</hostdev>
<hostdev mode='subsystem' type='pci' managed='no'>
  <driver name='vfio'/>
  <source>
    <address domain='0x0000' bus='0x__' slot='0x00' function='0x1'/>
  </source>
  <address type='pci' domain='0x0000' bus='0x05' slot='0x00' function='0x1'/>
</hostdev>

Warning: The GPU's PCI bus number can change across kernel versions (e.g. 0x09 on one kernel, 0x0b on another). Either resolve the address dynamically in your start script via lspci -D -d 1002:7550 and sed-substitute it into a template XML at runtime, or hardcode it and remember to update when you switch kernels.

managed='no' — your script handles the bind/unbind dance, not libvirt.
No <rom bar='off'/> — the VBIOS comes from ACPI VFCT. With rombar=0, OVMF can't find the GOP driver and the monitor stays black.
No <rom file='...'/> — not needed on kernel ≥ 6.13 with Navi 48.

CPU flags

<cpu mode='host-passthrough' check='none' migratable='off'>
  <topology sockets='1' dies='1' clusters='1' cores='4' threads='2'/>
  <cache mode='passthrough'/>
  <feature policy='require' name='topoext'/>
  <feature policy='disable' name='hypervisor'/>
</cpu>

Plus a QEMU commandline override (because libvirt's -cpu gets overridden by qemu:commandline):

<qemu:commandline xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>
  <qemu:arg value='-cpu'/>
  <qemu:arg value='host,migratable=off,topoext=on,svm=on,npt=on,nrip-save=on,vmcb-clean=on,flushbyasid=on,decodeassists=on,pause-filter=on,pfthreshold=on,v-vmsave-vmload=on,vgif=on,avx2=on,bmi1=on,bmi2=on,fma=on,monitor=off,hypervisor=off,hv-passthrough=on,kvm=off,pmu=off,kvm-hint-dedicated=on,host-cache-info=on,l3-cache=off,ucode-rev=0xYOURREV,hv-vendor-id=AuthenticAMD'/>
  <qemu:arg value='-overcommit'/>
  <qemu:arg value='cpu-pm=on'/>
  <qemu:arg value='-fw_cfg'/>
  <qemu:arg value='opt/ovmf/X-PciMmio64Mb,string=65536'/>
  <qemu:arg value='-machine'/>
  <qemu:arg value='x-oem-id=ALASKA,x-oem-table-id=A M I '/>
</qemu:commandline>

Critical: if you use -cpu in qemu:commandline, it completely overrides libvirt's generated -cpu line. All features from the XML <cpu> block are thrown away. You must put everything in the qemu:commandline version — hypervisor=off, hv-passthrough=on, all SVM flags if you need nested virt, everything.

Pinning the microcode revision

Get your host's microcode revision:

grep microcode /proc/cpuinfo | head -1

Add it to the -cpu line as ucode-rev=0xYOURREV. Without this, Windows caches the microcode revision on first boot and BSODs with MICROCODE_REVISION_MISMATCH if you ever boot a different host kernel that loads a different microcode update.

ACPI OEM strings (QEMU ≥ 11.0)

<qemu:arg value='-machine'/>
<qemu:arg value='x-oem-id=ALASKA,x-oem-table-id=A M I '/>

Replaces the default BOCHS/BXPC OEM IDs in ACPI tables. No QEMU rebuild needed — this is a runtime flag since ~QEMU 8.x.

OVMF MMIO window

<qemu:arg value='-fw_cfg'/>
<qemu:arg value='opt/ovmf/X-PciMmio64Mb,string=65536'/>

Expands OVMF's 64-bit MMIO window to 64 GiB so ReBAR can map the 9070 XT's BARs. Without this, ReBAR collapses to 256 MiB in-guest.

9. Anti-detection hardening

Vector	Fix
CPUID hypervisor bit	`hypervisor=off` in `-cpu`
KVM signature	`kvm=off` + `<kvm><hidden state='on'/></kvm>`
Hyper-V vendor ID	`hv-vendor-id=AuthenticAMD` in `-cpu`
SMBIOS/DMI strings	`<sysinfo type='smbios'>` with values from `dmidecode`
MAC OUI	Set `<mac address='XX:XX:XX:...'/>` with a real OEM OUI, not `52:54:00`
Virtio device IDs	Use SATA/AHCI for disks, `e1000e` for network (no `1af4:`)
ACPI OEM IDs	`-machine x-oem-id=ALASKA,x-oem-table-id=A M I`
Microcode revision	`ucode-rev=0xYOURREV` in `-cpu`

After boot, verify in the guest:

Task Manager → CPU → "Virtual machine" should say No
msinfo32 → no "hypervisor has been detected"
Device Manager → no Red Hat VirtIO devices

10. The MICROCODE_REVISION_MISMATCH BSOD

If Windows BSODs with this on boot, the cause is Windows' VBS/Hyper-V stack checking the CPU microcode revision. Fix by disabling it offline:

Mount the guest disk:

sudo modprobe nbd max_part=8
sudo qemu-nbd --connect=/dev/nbd0 -f raw /path/to/disk.img
sudo mount -t ntfs3 /dev/nbd0p3 /mnt/win
sudo mount -t vfat /dev/nbd0p1 /mnt/winefi

Disable VBS + HVCI in SYSTEM hive (using hivexsh -w):

cd \ControlSet001\Control\DeviceGuard
setval 3
CachedDrtmAuthIndex
dword:0
RequireMicrosoftSignedBootChain
dword:0
EnableVirtualizationBasedSecurity
dword:0
commit

cd \ControlSet001\Control\DeviceGuard\Scenarios
add HypervisorEnforcedCodeIntegrity
cd HypervisorEnforcedCodeIntegrity
setval 2
Enabled
dword:0
WasEnabledBy
dword:0
commit

hivexsh gotcha: setval value names must be BARE (no quotes). setval N replaces ALL values at the current node with the next N name/value pairs — if the node has other values you want to keep, include them all.

Disable hypervisor launch in BCD. First find your default loader GUID:

hivexget /mnt/winefi/EFI/Microsoft/Boot/BCD '\Objects\{9dea862c-5cdd-4e70-acc1-f32b344d4795}\Elements\23000003'

Then set hypervisorlaunchtype (element 250000f0) to off:

cd \Objects\{YOUR-LOADER-GUID}\Elements
add 250000f0
cd 250000f0
setval 1
Element
hex:3:00,00,00,00,00,00,00,00
commit

Then pin ucode-rev in the -cpu line so it never happens again.

11. Things that will wedge the GPU

virsh destroy while the GPU is active — force-kills QEMU mid-operation, corrupts the GPU's SMU firmware. The card becomes completely unresponsive (trn=2 ACK should not assert). Only a host reboot recovers it. Always shut down from inside Windows.
Rebooting the guest is safe — <on_reboot>restart</on_reboot> does an internal QEMU reset. The GPU stays on vfio-pci, the revert script does NOT fire.
Guest BSOD — let it sit or auto-reboot. Do not virsh destroy it. If you must kill it, SSH in and try virsh shutdown win10gaming --mode acpi first.

12. Onboard audio passthrough (QEMU ≥ 11.0.1 workaround)

If your onboard audio controller shares a PCI reset domain with another function (common on AMD B550/X570), QEMU 11.0.1+ will refuse to start with:

vfio: Cannot reset device, depends on group XX which is not owned

Workaround: don't include the audio device in the XML. Instead, hot-plug it after the VM starts:

virsh attach-device win10gaming /tmp/audio-hostdev.xml --live

This bypasses QEMU's startup reset-domain check. The device attaches fine after QEMU is already running.

13. Forum threads that helped

Proxmox forums — "PVE9 + AMD 9070xt now work" — uzumo's hookscript pattern (amdgpu unbind → BAR2 resize → vfio bind)
Proxmox forums — "WORKING Amd RX 9070xt support" — confirmed: disable_idle_d3=1 makes things worse
Reddit r/VFIO — "AMD Radeon RX 9070 (XT) Reset Bug" — confirmed: let amdgpu init first, don't pre-bind vfio
Reddit r/VFIO — "RX 9070 XT passthrough on Proxmox" by drlokey — dual-GPU writeup confirming the "opposite rules" for RDNA 4 vs older AMD
Level1Techs — "VFIO Pass-through working on 9070XT"
GitHub Gist — gdesatrigraha "VFIO AMD RX 9070 XT GPU Passthrough"
Arch Wiki — "PCI passthrough via OVMF"

PhialsBasement/SGPU-VFIO-9070xt.md

Select an option

No results found

Select an option

No results found

Single-GPU Passthrough: AMD RX 9070 XT (Navi 48 / RDNA 4) on CachyOS

Hardware

Key facts about RDNA 4 / Navi 48 passthrough

BIOS settings

1. Kernel cmdline

2. Modules and initramfs

`/etc/modprobe.d/kvm.conf`

`/etc/mkinitcpio.conf`

What NOT to create

3. Required packages

4. IOMMU group verification

5. The D3 problem and how to solve it

What causes it

The fix: lock the GPU in D0 before unbinding

Use `managed='no'` on PCI hostdevs

6. Start script

7. Revert script (GPU reclaim on VM shutdown)

The `driver_override` trap

8. VM XML — the important parts

PCI hostdevs — `managed='no'`

CPU flags

Pinning the microcode revision

ACPI OEM strings (QEMU ≥ 11.0)

OVMF MMIO window

9. Anti-detection hardening

10. The MICROCODE_REVISION_MISMATCH BSOD

11. Things that will wedge the GPU

12. Onboard audio passthrough (QEMU ≥ 11.0.1 workaround)

13. Forum threads that helped

writecr3 commented Aug 3, 2026

Uh oh!

PhialsBasement/SGPU-VFIO-9070xt.md

Single-GPU Passthrough: AMD RX 9070 XT (Navi 48 / RDNA 4) on CachyOS

Hardware

Key facts about RDNA 4 / Navi 48 passthrough

BIOS settings

1. Kernel cmdline

2. Modules and initramfs

/etc/modprobe.d/kvm.conf

/etc/mkinitcpio.conf

What NOT to create

3. Required packages

4. IOMMU group verification

5. The D3 problem and how to solve it

What causes it

The fix: lock the GPU in D0 before unbinding

Use managed='no' on PCI hostdevs

6. Start script

7. Revert script (GPU reclaim on VM shutdown)

The driver_override trap

8. VM XML — the important parts

PCI hostdevs — managed='no'

CPU flags

Pinning the microcode revision

ACPI OEM strings (QEMU ≥ 11.0)

OVMF MMIO window

9. Anti-detection hardening

10. The MICROCODE_REVISION_MISMATCH BSOD

11. Things that will wedge the GPU

12. Onboard audio passthrough (QEMU ≥ 11.0.1 workaround)

13. Forum threads that helped

writecr3 commented Aug 3, 2026

Uh oh!

`/etc/modprobe.d/kvm.conf`

`/etc/mkinitcpio.conf`

Use `managed='no'` on PCI hostdevs

The `driver_override` trap

PCI hostdevs — `managed='no'`