VM with GPU passthrough - disabling default framebuffer?
So after fixing Ryzen Gen1 IOMMU issues (see here), I can pass my GPU to a VM. Problem is, the default framebuffer is still present and is the default graphics (for Linux or Windows).
My googling shows me there's a
gfx_passthruoption in Xen that tells Xen to disable the default framebuffer and use the passed-through GPU as the only VGA for the VM. Is there a way to do the same in XCP-NG?
I have no experience with that. What's your GPU?
It's an Nvidia 1070
With an Nvidia consumer grade GPU, passthrough won't work, because Nvidia driver will refuse to load in a VM.
I know it won't work with the Nvidia drivers, but for now I want it to start with the
nouveaudriver on Linux, and at least get something working.
It seems someone made it with Nvidia consumer GPU passthrough: he used modded drivers that get rid of the check.
I know there are... workarounds around that (e.g. for KVM you can hide the fact that it's running inside a VM, and I believe there are similar solutions for Xen).
But first things first - I want to get rid of that default framebuffer. Is there a way to pass 'base' Xen config options through XCP-ng (e.g. with an
@woopla I'm not sure if this will work in your setup, but I've thought I'll share the solution which worked for me as I tried hard to get rid of bloody framebuffer (which was making the console in XCP-ng Center and in XOA almost unreadable due to tiny or blurred font).
After many hours of googling and trying various settings in
/etc/default/grub(which theoretically should work, but didn't) I found unix.stackexchange.com/questions/346090/disable-framebuffer-in-qemu-guests.
" disable the framebuffer via a bochs_drm module parameter - i.e. via setting it on the guest kernel command line: bochs_drm.fbdev=off "
Precisely, I put into
/etc/default/grubthe following line:
edit: I forgot to mention: the above line is for a VM system, not for XCP-ng host.
(The systemd entry is unrelated to fb issue, but I'm quoting it here as a additional tip - I need it to at least partially work around systemd fascist plague).
I wonder: will this bochs tip help you?
@MajorTom thanks that could be a solution. In the end I moved my single-machine Homelab to Proxmox, because I have way better control in this specific use-case - I can see IOMMU groupings and figure out which USB controller I can also passthrough. And this works fine, I'm posting this from this VM.
XCPng isn't bad, it´s just not suited to my very specific use case.