[vfio-users] Blank screen but no obvious errors for NVIDIA 750 Ti passthrough on Haswell i7-4770

[Jeremy Visser]

On 30 July 2017 at 21:15, Torbjorn Jansson
<torbjorn.jansson at mbox200.swipnet.se> wrote:
> i assume the vm appears to start but doesn't actually output anything on the
> screen and doesn't boot properly.
> if so, try waiting a very long time, say 10-15 minutes or so and see if it
> eventually boots.

Actually the VM starts immediately.

I can tell by doing a bit of prep beforehand and installing either an
SSH or VNC server and poking around. The card is detected (lspci, or
Device Manager in the guest) but doesn't actually work in any way no
matter if it's a low level console, open source drivers, or binary
drivers. Using KVM hidden mode has exactly zero effect.

Also if I enable a serial port, the TianoCore UEFI decides to use
serial as the console despite my graphics card being available.
However if I add a QXL virtual video card, TianoCore is satisfied
enough to use that as the console instead of the serial.

So clearly the problem is more basic than the operating system but can
be immediately reproduced merely from the TianoCore interface.

> yesterday my vm with a gtx 970 took forever to start, i tried several times
> and then just left it and nearly forgot about it, then later to my surprise
> it had booted.

I tried leaving it anyway for a good half hour. No difference.