Need tech help. I have two GPUs in my motherboard. The motherboard keeps selecting the wrong GPU as the one to output to. In Linux I can't find any settings to make the os use the correct GPU. Anytime I search for this it ends up being an integrated vs dedicated thing. Butni have two dedicated cards. I need the PC to only use one since the other will be passed to vfio
@roxie
https://forums.centos.org/viewtopic.php?t=60531
I would higjly reccomend looking into what's called a 'pci-stub' - its basically a way to tell the kernel to immediately park a PCI device with a dummy driver so it can be safely detached and reattached after the system has fully booted.
This is useful when you need the system to stay hands-off with a particular device like a GPU until you're fully booted and ready for something like vfio to pick it up (which I presume is for PCI paasthrough in your case - as it was for me)
If you're using UEFI to boot you may also need `dracut` to help you rebuild the init ramdisk to prevent the GPU driver from being loaded when the init image is passed to the kernel.
If you have any questions feel free to ask - it can take a while to grasp how it all fits together and my explanation may not convey the useful bits effectively for you.
https://forums.centos.org/viewtopic.php?t=60531
I would higjly reccomend looking into what's called a 'pci-stub' - its basically a way to tell the kernel to immediately park a PCI device with a dummy driver so it can be safely detached and reattached after the system has fully booted.
This is useful when you need the system to stay hands-off with a particular device like a GPU until you're fully booted and ready for something like vfio to pick it up (which I presume is for PCI paasthrough in your case - as it was for me)
If you're using UEFI to boot you may also need `dracut` to help you rebuild the init ramdisk to prevent the GPU driver from being loaded when the init image is passed to the kernel.
If you have any questions feel free to ask - it can take a while to grasp how it all fits together and my explanation may not convey the useful bits effectively for you.
@roxie Oh that's a good question - I think you'd need to tell grub which output to use separately from the kernel. There might be a grub2-mkconfig option for that I would expect.
@seasharp that might be worth a shout. I just need to know what the password entry uses and if its still "grub" and then once it unlocks like then the kernal will do the rest
@roxie for sure! Worst case you're punching your root drive decryption passphrase in using the second monitor but after that the kernel and the stub driver should do the rest, as you said.
Good luck :)
Good luck :)
