Re: [BUG][AMD IOMMU][VFIO] IVMD exclusion ranges block GPU passthrough on ASUS GA403UI, reproduced on 7.4-rc0

[César Zapata]

Hi Vasant, Suravee,

Thank you for the response.

I can now confirm that the AMD IVMD v2 patch series resolves the reported VFIO passthrough failure on my ASUS ROG Zephyrus G14 GA403UI.

After submitting the original report, I applied all four patches from the following series to an unmodified Linux 7.2.8 source tree:

[PATCH v2 0/4] iommu/amd: IVMD handling cleanup and ivmd= boot override
https://lore.kernel.org/all/20260424092213.16976-1-suravee.suthikulpanit@xxxxxxx/

Test configuration

System: ASUS ROG Zephyrus G14 GA403UI (2024)

CPU: AMD Ryzen 9 8945HS

GPU: NVIDIA RTX 4070 Laptop GPU (10de:2860)

GPU audio: NVIDIA HD Audio (10de:22bd)

Host: Fedora 44 Workstation

Kernel: 7.2.8-ivmdv2-test1 (Linux 7.2.8 + IVMD v2 series)

Virtualization: QEMU/KVM with libvirt 12.0.0

Guest: Windows 11 Pro

NVIDIA guest driver: 566.07

Before applying the patches

The firmware's IVMD type 0x22 entries, with exclusion flag 0x08, produced the following reserved region for NVIDIA IOMMU group 14:

0x0000000097d36000 0x0000000097d37fff direct

VFIO rejected GPU assignment with:

Firmware has requested this device have a 1:1 IOMMU
mapping, rejecting configuring the device without
a 1:1 mapping.

This failure was reproduced on the unpatched Fedora kernels and upstream mainline 7.4.0-rc0 described in my original report.

After applying the IVMD v2 series

The affected exclusion region is represented as reserved rather than direct, and the previous VFIO IOMMU-domain rejection no longer occurs.

More importantly, I verified actual GPU passthrough functionality:

Both NVIDIA PCI functions (01:00.0 and 01:00.1) were assigned to the Windows 11 guest using libvirt-managed VFIO.

Windows booted successfully and initialized the NVIDIA driver without a reported device error.

nvidia-smi inside the guest detected the RTX 4070 Laptop GPU with driver 566.07.

The Windows desktop was displayed at 1920×1080 through the laptop's physical NVIDIA-connected HDMI output.

After shutting down the guest, both PCI functions returned successfully to their original host drivers: nouveau and snd_hda_intel.

GPU assignment and host recovery were exercised through multiple VM start/shutdown cycles without requiring a Fedora host reboot.

I also compared the four patched source files against a fresh application of the original v2 series. They match apart from an indentation-only whitespace difference in drivers/iommu/amd/iommu.c; no functional source differences were identified.

I have not tested the newly introduced ivmd= boot parameter, and I have not performed extended stress or suspend/resume testing.

Conclusion

The v2 series fixes the original IOMMU_RESV_DIRECT blocker on this ASUS platform and, importantly, enables successful end-to-end NVIDIA GPU passthrough to a Windows 11 guest.

Thank you for working on this fix. I would be happy to test the next revision of the series, including any additional diagnostics or regression checks you would find useful.

Tested-by: César Zapata

Regards,
César Zapata

________________________________________
De: Vasant Hegde <vasant.hegde@xxxxxxx>
Enviado: viernes, 23 de octubre de 2026 3:21
Para: César Zapata <el_caesar@xxxxxxxxxxx>; joro@xxxxxxxxxx <joro@xxxxxxxxxx>; Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
Cc: suravee.suthikulpanit@xxxxxxx <suravee.suthikulpanit@xxxxxxx>; will@xxxxxxxxxx <will@xxxxxxxxxx>; robin.murphy@xxxxxxx <robin.murphy@xxxxxxx>; iommu@xxxxxxxxxxxxxxx <iommu@xxxxxxxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx <linux-kernel@xxxxxxxxxxxxxxx>
Asunto: Re: [BUG][AMD IOMMU][VFIO] IVMD exclusion ranges block GPU passthrough on ASUS GA403UI, reproduced on 7.4-rc0
 
Hi Cesar,


On 10/22/2026 11:22 PM, César Zapata wrote:
> Algunos contactos que recibieron este mensaje no suelen recibir correos electrónicos de el_caesar@xxxxxxxxxxx. Por qué es esto importante<https://aka.ms/LearnAboutSenderIdentification>
> Hello,
> I would like to report a reproducible AMD IOMMU/VFIO issue on an ASUS ROG Zephyrus G14 GA403UI, now confirmed using an upstream Linux Mainline Vanilla 7.4.0-rc0 kernel without the proprietary NVIDIA driver.
> The firmware publishes broad IVMD exclusion ranges that Linux exposes as IOMMU_RESV_DIRECT. Consequently, VFIO refuses to establish an IOMMU domain for an otherwise isolated NVIDIA GPU.
> System information

Thanks for the report. I believe below mention series should fix this issue.

@Suravee, Can you respin the series?

-Vasant