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Code 31 - Fixed when passed the seemingly wrong subsystem ids?

I have a working GPU pass-through for the dGPU of my Precision 7450 Muxed Dell Laptop. At first my GPU wouldn’t get recognized at all by the OS and I couldn’t install the nvdia driver as it didn’t find the device.

I read somewhere on reddit that this is because the subsystem device IDs are incorrect in the VM for my Quadro T1000. As such I attempted to set them using QEMU commands

<qemu:commandline>
<qemu:arg value='-set'/>
<qemu:arg value='device.hostdev0.x-pci-sub-vendor-id=0x1028'/>
<qemu:arg value='-set'/>
<qemu:arg value='device.hostdev0.x-pci-sub-device-id=0x0926'/>

</qemu:commandline>

It works but the strange thing is that I took the ids of the wrong subsystem as the correct one for the Quadro is the following:

01:00.0 VGA compatible controller [0300]: NVIDIA Corporation TU117GLM [Quadro T1000 Mobile] [10de:1fb9] (rev a1)
Subsystem: NVIDIA Corporation TU117GLM [Quadro T1000 Mobile] [10de:0000]
Kernel driver in use: vfio-pci
Kernel modules: nouveau

When I look at what device have that vendor ID I get a lot of PCI devices

[[email protected] ~]$ lspci -nnk | grep 1028
Subsystem: Dell Device [1028:0926]
Subsystem: Dell UHD Graphics 630 (Mobile) [1028:0926]
Subsystem: Dell Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor Thermal Subsystem [1028:0926]
Subsystem: Dell Xeon E3-1200 v5/v6 / E3-1500 v5 / 6th/7th/8th Gen Core Processor Gaussian Mixture Model [1028:0926]
Subsystem: Dell Cannon Lake PCH Thermal Controller [1028:0926]
Subsystem: Dell Cannon Lake PCH USB 3.1 xHCI Host Controller [1028:0926]
Subsystem: Dell Cannon Lake PCH Shared SRAM [1028:0926]
Subsystem: Dell Cannon Lake PCH Serial IO I2C Controller [1028:0926]
Subsystem: Dell Cannon Lake PCH Serial IO I2C Controller [1028:0926]
Subsystem: Dell Cannon Lake Mobile PCH SATA AHCI Controller [1028:0926]
Subsystem: Dell Device [1028:0926]
Subsystem: Dell Cannon Lake PCH cAVS [1028:0926]
Subsystem: Dell Cannon Lake PCH SMBus Controller [1028:0926]
Subsystem: Dell Cannon Lake PCH SPI Controller [1028:0926]
Subsystem: Dell Ethernet Connection (7) I219-LM [1028:0926]
Subsystem: Dell JHL7540 Thunderbolt 3 NHI [Titan Ridge 4C 2018] [1028:0926]
Subsystem: Dell JHL7540 Thunderbolt 3 USB Controller [Titan Ridge 4C 2018] [1028:0926]
Subsystem: Dell RTS5260 PCI Express Card Reader [1028:0926]

I’ve tried setting the card to the correct subsystem id but it doesn’t work when I do that o_O

Anyway ideas as to what might have happened would be much appreciated.