Hi,

 

First I need to say that I'm quite a noob in virtualization, but I've been searching the forum for some answer and I must recognize that I'm quite lost... 😅

I'm also not an native english speaker so please forgive me if my explications aren't clear !

My NAS is currently running with the following config :

 

M/B: Micro-Star International Co., Ltd. MAG B550 TOMAHAWK (MS-7C91) Version 2.0 - s/n: K616466956

BIOS: American Megatrends Inc. Version A.20. Dated: 08/06/2020

CPU: AMD Ryzen 7 3700X 8-Core @ 3600 MHz

Cache: 512 KiB, 4096 KiB, 32768 KiB

Memory: 16 GiB DDR4 (max. installable capacity 128 GiB)

4x4TB WD in the array (one in parity)

1 SSD Samsung 840 EVO 500GB as a cache device

GPU : an old Sapphire R9 280X TriX OC 

 

My Nas is currently set up next to my TV, so I wish to set a Windows 10 VM with a passthrough to my GPU and 2 USB (Keyboard and mouse, plugged directly to the NAS) to use it mainly for some light gaming or web browsing.

I tried to follow this Spaceinvader One tuto : 

 

 

The first trouble I faced was after the SMV and IOMMU activation in the BIOS : my unraid wouldn't even boot up (I have a bunch of AMD-Vi : . I found the trick, wich is to add following command in the Syslinux configuration before activating the iommu :

iommu=pt

(I also tried the 'iommu=soft but it did not help me)

 

As a result, I am now able to activate IOMMU in the bios, start unraid and to passthroug my GPU when I edit my Windows 10 VM (I managed to find my graphic ROM BIOS) and the usb devices are detected :

 

NOTE : I tried to use the VFIO PCI Config plugin but the process just desactivate the group I chose into the VM, probably because of the "iommu=pt" command, I think), so as the device are there without any use of the plugin, I continue the process without it.

 

But when I select the USB devices, and then run the VM, the VM displays on my tv but I can't "press any key to start the boot from CD". The strangest thing is that the screen seems to remains blocked at this stage (when I do not select the keyboard in the VM USB Devices, if no key is press, the boot "continues" without any setup, but not with the keyboard selected) . I tried 3 différent keyboard, so I'm quite confident it is not linked to the device....

Off course I looked also into the groups (My VM Manager is set as "both" for 'PCIe ACS override") and my two USB ports are in a separate group, along with some others USB but with nothing else, and of course without my USB flash key containing Unraid)

 

I'm sure you will find this simple but I dug into it and I'm totaly unsure of what I still can do...

Some idea would be greatly appreciated! If some other informations are needed, I would be please to give them!

Thank you !

@mathieuhantz The usual way is to setup a VM without GPU passthrough via VNC, install the virtio drivers for network and make sure everything works. Enabling RDP or setting up remote software like Teamviewer or Anydesk is also a good advice, because as soon as you use a GPU for passthrough VNC should be disabled. Otherwise VNC will always be the primary GPU and the passed through one wont work.

 

The "PCIe ACS Override" option has nothing to do with passing through USB devices like the 3 showed in your screen. It is needed for splitting up groups for PCIe passthrough in case you have a USB controller itself grouped with other devices and you want to use the full controller inside the VM, same for GPUs or network controllers.