HOST VRAM Leak when performs android-x86 window rotation with Virt-GPU

I will report something strange thing about host VRAM leakage after anroid-x86 window rotation when it runs with virt-gpu(+ virgl-renderer)

Please watching below video link.

https://www.youtube.com/watch?v=mJIbGZLWF1s&feature=youtu.be

(orginal video file : https://drive.google.com/file/d/1lkdTx_8yTbSVjKXlnxnnk96fWe-w6Mxb/view?usp=sharing)

I don't sure what is the problem...

Here are my tested history
--------------------------------------------------------------------------------------------------
Install android-x86 on I7 desktop PCs with intel UHD GPU  - No leak.
Install android-x86 on I7 desktop PCs with NVIDIA GTX GPU series - No leak.
Install android-x86 on guest machine emulated skylake cpu with QEMU(+virt-gpu, virgl-renderer) - Leak
(HOST CPU - I5, INTEL UHD GPU)
Install android-x86 on guest machine emulated skylake cpu with QEMU(+virt-gpu, virgl-renderer) - Leak
(HOST CPU - I7, NVIDIA GTX GPU)

COMMON:
In case of NVIDIA GPU : check vram using nvidia-smi
In case of intel UHD GPU : check shared-vram using free cmd

We checked guest android-x86 system down when vram is full after performing many rotation
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Is it virt-gpu driver's problem?

I hope someone can help me...

Thanks in advance!!