Re: "xrandr" cannot find "1920x1080" as an available mode when using OpenBSD as a host from Linux with the "virtio" driver

Yeah, autodetection doesn't do the right thing. You can
do better with a custom xorg config.

Accelerated X11 under vm is not going to work, so you are
stuck with 2 options:

1. wsfb if your system supports UEFI and console framebuffer is on
2. vesa (needs aperture sysctl)

Here is an example for wsfb:

1. Create /etc/X11/xorg.conf.d/
2. Place custom monitor config in /etc/X11/xorg.conf.d/00-monitor.conf

Section "Device"
Identifier "Framebuffer"
Driver "wsfb"
BoardName "Graphics Adapter"
EndSection

Section "Monitor"
Identifier "Monitor"
ModelName "Monitor"
HorizSync 1.0 - 1000.0
VertRefresh 1.0 - 1000.0
EndSection

Section "Screen"
Identifier "Screen"
Device "Framebuffer"
Monitor "Monitor"
DefaultDepth 24
SubSection "Display"
Viewport 0 0
Depth 24
Modes "1920x1080"
EndSubSection
EndSection

3. restart your Xorg server.

Cheerio,
Chris

On Tue, Mar 29, 2022 at 09:47:07PM +0200, rempas@tutanota.com wrote:
> Hello! I'm a new user trying OpenBSD. I'm trying OpenBSD with QEMU using
> a Linux machine (more specifically Arch Linux, if that matters) as a host. Now,
> the problem happens when I use the "virtio" driver to launch OpenBSD. In this
> case, "xrand" will report that there was no "1920x1080" resolution available to
> use. The max resolution I can use is "1280x768". The max refresh rate is "61.00"
> while my screen support "75.00" so that's another problem. Now, when I use
> the "std" driver to launch the virtual machine, xrandr can then set see that my
> resolution is "1920x1080" and allows me to choose it. However, in that case,
> for some reason, xrandr reports that my max refresh rate is "0.00" which is
> weird to say the least...
>
> So at this point, I'm pretty sure that it has to do with the driver. DragonflyBSD
> had the same problem. The exact command I'm using to launch the virtual
> machine is:
>
> ```
> qemu-system-x86_64 -enable-kvm -drive file=VMs/Generic.img -m 2.5G \
> -cpu host -smp 6 -vga <DRIVER> -display sdl,gl=on
> ```
>
> Where <DRIVER> is the driver that is used, so "virtio" or "std". But again, I want
> to use "virtio" because it has better performance.
>
> Another information that is probably important is that my GPU is and AMD card,
> more specifically, AMD RX 560. I also don't know if OpenBSD uses "amdgpu" or
> "radeon" as the GPU driver at this point. I wasn't able to find how I can see that.
>
> That was my first email to this list so I hope, I followed all the rules. Of course I
> should also say that I have searched as much as I could before posting this email
> and I couldn't find something. So thanks a lot to anyone that will read this email!
> I know how precious your time is and I really appreciate it!
>