virt-manager and virgl / Spice / OpenGL

[Scott Talbert]

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?

It looks as if virtio-gpu and glamor are loaded/running:

talbert at debian-unstable:~$ grep virtio ~/.local/share/xorg/Xorg.0.log
[    28.590] (II) modeset(0): [DRI2]   DRI driver: virtio_gpu
[    28.590] (II) modeset(0): [DRI2]   VDPAU driver: virtio_gpu
[    28.603] (II) AIGLX: Loaded and initialized virtio_gpu

talbert at debian-unstable:~$ grep glamor ~/.local/share/xorg/Xorg.0.log
[    28.451] (II) Loading sub module "glamoregl"
[    28.451] (II) LoadModule: "glamoregl"
[    28.451] (II) Loading /usr/lib/xorg/modules/libglamoregl.so
[    28.456] (II) Module glamoregl: vendor="X.Org Foundation"
[    28.527] (II) modeset(0): glamor X acceleration enabled on virgl
[    28.528] (II) modeset(0): glamor initialized

Host GPU is:
[talbert at deasil ~]$ lspci | grep VGA
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] 
Venus XTX [Radeon HD 8890M / R9 M275X/M375X] (rev 83)

One other note: there is some intermittent display corruption while the 
guest OS is booting.

Thanks,
Scott