Try to make GPU Passthrough

Support Virtualization
,
1

Hi,

Have a Radeon RX 5500 XT GPU and a MSI B360M GAMING PLUS Motherboard.
This is my only GPU for Host & Guest have possiblity to use it for make a GPU Passthrough ?
Because on my side is not working.

If you have any idea for try to fix it ?

Best Regards

Issue :

Unable to complete installation : « unsupported configuration: host doesn't support passthrough of host PCI devices »

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/asyncjob.py", line 65, in cb_wrapper
    callback(asyncjob, *args, **kwargs)
  File "/usr/share/virt-manager/virtManager/createvm.py", line 2001, in _do_async_install
    installer.start_install(guest, meter=meter)
  File "/usr/share/virt-manager/virtinst/install/installer.py", line 701, in start_install
    domain = self._create_guest(
  File "/usr/share/virt-manager/virtinst/install/installer.py", line 649, in _create_guest
    domain = self.conn.createXML(install_xml or final_xml, 0)
  File "/usr/lib/python3.9/site-packages/libvirt.py", line 4376, in createXML
    raise libvirtError('virDomainCreateXML() failed')
libvirt.libvirtError: unsupported configuration: host doesn't support passthrough of host PCI devices

dmesg | grep -i -e DMAR -e IOMMU
[    0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-5.13-x86_64 root=UUID=184dc40c-f68f-403b-b83d-5351e5d8c22f rw quiet amd_iommu=on rd.driver.pre=vfio-pc kvm.ignore_msrs=on radeon.audio=1
[    0.030075] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-5.13-x86_64 root=UUID=184dc40c-f68f-403b-b83d-5351e5d8c22f rw quiet amd_iommu=on rd.driver.pre=vfio-pc kvm.ignore_msrs=on radeon.audio=1
[    0.262435] iommu: Default domain type: Translated 
[    0.353563] AMD-Vi: AMD IOMMUv2 driver by Joerg Roedel <jroedel@suse.de>
[    0.353563] AMD-Vi: AMD IOMMUv2 functionality not available on this system

dmesg | grep -i vfio
[    0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-5.13-x86_64 root=UUID=184dc40c-f68f-403b-b83d-5351e5d8c22f rw quiet amd_iommu=on rd.driver.pre=vfio-pc kvm.ignore_msrs=on radeon.audio=1
[    0.030075] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-5.13-x86_64 root=UUID=184dc40c-f68f-403b-b83d-5351e5d8c22f rw quiet amd_iommu=on rd.driver.pre=vfio-pc kvm.ignore_msrs=on radeon.audio=1
2

No, you need a GPU for the Host. Every OS needs it own GPU. If you only have one real GPU, you can only use a virtualized GPU in the VM. If you have 2 real GPUs (for example a iGPU in your CPU and a dedicated GPU) you can pass through the dGPU to the VM.

3

Fully agree with @xabbu . Additionally I would mention that the only gpu which supports using the host and IOMMU of the same GPU is Intel: Intel GVT-g - ArchWiki

4

Thank for this information is good to know.