[Qemu-devel] No uhd (3840x2160) guest res?

[Qemu-devel] No uhd (3840x2160) guest res?

[Dr. David Alan Gilbert]

My guests don't seem to offer the standard uhd resolution of 3840x2160
- what should be providing that?

I'm running an f27 gnome (X or wayland) guest with:

./x86_64-softmmu/qemu-system-x86_64 -device virtio-vga --enable-kvm -m 2G /home/vmimages/fedora27.qcow2

and the guest lists:
4096x2160
2480x1680
2560x1600
1920x1440
1856x1392
1792x1344
2048x1152
1920x1200
1920x1080
(and smaller)

given that it can offer 4096x2160, I assume it's not running out of RAM.

I couldn't find anywhere with those higher resolutions listed
in seabios to consider changing.

Dave

--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Re: [Qemu-devel] No uhd (3840x2160) guest res?

[Gerd Hoffmann]

On Tue, Dec 12, 2017 at 08:20:41PM +0000, Dr. David Alan Gilbert wrote:
> My guests don't seem to offer the standard uhd resolution of 3840x2160
> - what should be providing that?
> 
> I'm running an f27 gnome (X or wayland) guest with:
> 
> ./x86_64-softmmu/qemu-system-x86_64 -device virtio-vga --enable-kvm -m 2G /home/vmimages/fedora27.qcow2
> 
> and the guest lists:
> 4096x2160
> 2480x1680
> 2560x1600
> 1920x1440
> 1856x1392
> 1792x1344
> 2048x1152
> 1920x1200
> 1920x1080
> (and smaller)
> 
> given that it can offer 4096x2160, I assume it's not running out of RAM.
> 
> I couldn't find anywhere with those higher resolutions listed
> in seabios to consider changing.

linux kernel has a list of standard vesa resolutions in drm somewhere,
iirc all virt drm drivers just use that for the mode list.

> 
> Dave
> 
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Re: [Qemu-devel] No uhd (3840x2160) guest res?

[Dr. David Alan Gilbert]

* Gerd Hoffmann (kraxel@redhat.com) wrote:
> On Tue, Dec 12, 2017 at 08:20:41PM +0000, Dr. David Alan Gilbert wrote:
> > My guests don't seem to offer the standard uhd resolution of 3840x2160
> > - what should be providing that?
> > 
> > I'm running an f27 gnome (X or wayland) guest with:
> > 
> > ./x86_64-softmmu/qemu-system-x86_64 -device virtio-vga --enable-kvm -m 2G /home/vmimages/fedora27.qcow2
> > 
> > and the guest lists:
> > 4096x2160
> > 2480x1680
> > 2560x1600
> > 1920x1440
> > 1856x1392
> > 1792x1344
> > 2048x1152
> > 1920x1200
> > 1920x1080
> > (and smaller)
> > 
> > given that it can offer 4096x2160, I assume it's not running out of RAM.
> > 
> > I couldn't find anywhere with those higher resolutions listed
> > in seabios to consider changing.
> 
> linux kernel has a list of standard vesa resolutions in drm somewhere,
> iirc all virt drm drivers just use that for the mode list.

I see drivers/video/fbdev/core/modedb.c, but there are modes that I see
in the guest that aren't in there; e.g. I see a 4096x2160 listed in the
guest (the 2480x1680 seems to have gone?!).  I don't see it in SeaBIOS
either.

Looking at the VESA CVT 1.2 standard I don't see a UHD def (it's got
some that are similar but not quite the right res).

(I do see a UHD mode defined in qxl, but qxl is unusable and qemu aborts
with newer guest kernels).

Dave


> > 
> > Dave
> > 
> > --
> > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK