virt-manager and virgl / Spice / OpenGL

[Marc-André Lureau]

Hi

On Tue, May 19, 2020 at 5:40 PM Scott Talbert <swt at techie.net> wrote:
>
> On Tue, 19 May 2020, Marc-André Lureau wrote:
>
> >> Hi,
> >>
> >> Is virgl/OpenGL support through virt-manager supposed to work and perform
> >> well?
> >>
> >> I have the following:
> >> Host OS: Fedora 32
> >> Guest OS: Debian Unstable
> >>
> >> In virt-manager, I have the following:
> >> Display Spice
> >>    Type: Spice server
> >>    Listen type: None
> >>    Password: Blank
> >>    Keymap: Blank
> >>    OpenGL: Checked & /dev/dri/renderD128
> >>
> >> Video Virtio
> >>    Model: Virtio
> >>    Ram: -
> >>    Heads: 1
> >>    3D acceleration: Checked
> >>
> >> In the guest OS:
> >> talbert at debian-unstable:~$ sudo dmesg | grep '\[drm\]'
> >> [    1.947975] [drm] pci: virtio-vga detected at 0000:00:01.0
> >> [    2.019988] [drm] features: +virgl +edid
> >> [    2.022522] [drm] number of scanouts: 1
> >> [    2.022529] [drm] number of cap sets: 2
> >> [    2.048982] [drm] cap set 0: id 1, max-version 1, max-size 308
> >> [    2.049125] [drm] cap set 1: id 2, max-version 2, max-size 688
> >> [    2.049332] [drm] Initialized virtio_gpu 0.1.0 0 for virtio0 on minor 0
> >>
> >> So it *seems* like things are configured correctly?  However, performance
> >> is not great.  Performance is much better if I switch back to QXL video.
> >
> > It looks like your setup should be fine. What performance are you
> > running? Local or remote? If it's 2D based anyway, chances are you get
> > similar results with QXL or virtio, probably with better QXL results
> > with the QXL Xorg driver.
>
> It's local.  I don't have any quantitative data on performance, just my
> observations on performance.  In the guest, I'm just running the default
> Debian DE (Gnome Shell) on Xorg.  Wayland performs worse.  Gnome Shell is
> 3D, right?

Yes. With virgl, make sure the virtio-gpu DRI driver is loaded (and
not the sw/llvmpipe). On Xorg, make sure glamor is running.

What's your host gpu?