Qubes gpu passthru causes crash and restart

[Vael_S]

hi all,
have issue with gpu passthrough where it causes system to completely reboot.
unknown the cause
help appreciated

[apparatus]

Did you follow this guide?

Create a Gaming HVM

Hardware To have an ‘HVM’ for gaming, you must have A dedicated GPU. By dedicated, it means: it is a secondary GPU, not the GPU used to display dom0. In 2023, ‘Nvidia’ and ‘Amd’ GPU work. Not tested with Intel GPUs. External GPU using thunderbolt work (Create a Gaming HVM - #8 by solene) A screen available for the gaming ‘HVM’. (It can be a physical monitor or just to have multiple cables connected to the screen and switching between input source) Dedicated gaming mouse and keyboard. …

Did you hide the GPU from dom0?

[Vael_S]

yes that is what i was following
yes i put the code to hide the device but it did not hide from the system it still was there

[apparatus]

Did you check it like this?

@taradiddles

Once you have rebooted, in dom0, type sudo lspci -vvn, you should see “Kernel driver in use: pciback” for the GPU you just hid.

What’s the value in the “Kernel driver in use:” for the GPU that you want to hide?
Maybe you didn’t hide it properly.

[Vael_S]

neuvau. still uses driver. maybe something else wrong?

[apparatus]

What’s the output of this command in dom0?

cat /proc/cmdline

You can remove the UUID from the output.

[Vael_S]

thank you. found issue. addition to statement was an iommu=0 so seems it was turn off in command line. have resolved that now thank you for that

[Vael_S]

i minimised the grub boot config file so that i will not have issues in that part again. i really do not understand the need for all the additions for the boot configuration.