[pve-devel] [PATCH qemu-server/pve-manager v1 0/2] add virtio-vga-gl Vulkan (venus) support

[Markus Frank]

On 2025-11-10 14:54, Thomas Lamprecht wrote:
> Am 10.11.25 um 12:40 schrieb Markus Frank:
>> To get an overview of the performance, see the benchmark below.
>>
>> supertuxkart (1.5) benchmark (default settings, vulkan, 1024x768):
>>
>> Host result (Granite Ridge integrated GPU):
>> * Total frame count: 8488
>> * Total profiling time (ms): 38139
>> * Steady FPS: 92
>> * Mostly stable FPS: 137
>> * Typical FPS: 194
>>
>> VM (host, 4 core, 8GiB) with venus (hostmem=8192M) result:
>> * Total frame count: 3321
>> * Total profiling time (ms): 38130
>> * Steady FPS: 58
>> * Mostly stable FPS: 75
>> * Typical FPS: 86
>>
> 
> Comparing with a benchmark in the VM with other displays would be also nice.
> Most interesting would be the default (vga IIRC) and qxl (SPICE).

I did, but I do not think the results are really comparable because all current display types use vulkan software rendering, which performs really badly.
See below:

VM virtio-gl (Vulkan, without venus, llvmpipe software rendering):
* Total frame count: 762
* Total profiling time (ms): 260786
* Steady FPS: 1
* Mostly stable FPS: 2
* Typical FPS: 2


To make a more meaningful comparison, it would be better to use OpenGL with virtio-gl.

This is the result I got in the same VM with virtio-gl and a similar supertuxkart benchmark using OpenGL instead of Vulkan:
VM virtio-gl (OpenGL, virgl):
* Total frame count: 2940
* Total profiling time (ms): 38128
* Steady FPS: 35
* Mostly stable FPS: 54
* Typical FPS: 77


OpenGL also requires software rendering with VGA and QXL.

vga (OpenGL, software rendering):
* Total frame count: 762
* Total profiling time (ms): 73867
* Steady FPS: 7
* Mostly stable FPS: 8
* Typical FPS: 10

qxl (OpenGL, software rendering):
* Total frame count: 762
* Total profiling time (ms): 75797
* Steady FPS: 7
* Mostly stable FPS: 8
* Typical FPS: 9

> 
>> This benchmark showed no significant differences in performance between
>> the various memory window sizes for venus.
> 
> I probably would not expose them then for now.