Transcoding errors occuse frequently when gvt-g is enabled

[origalin]

I've tested on both host and guest machines. When slightly heavy transcoding (1080p 20mbps+) load was passed to GPU, it failed. However, it works well under 720p 8mbps. If I disable GVT-g, it runs perfectly on the host machine.
How do I collect helpful logs & info?

Host OS: PVE 7.2-3 Linux 5.15.30-2-pve #1 SMP PVE 5.15.30-3
Guest OS: Openmediavault 6.0.30-1 Linux 5.16.0-0.bpo.4-amd64
CPU: Intel 8700
GPU: UHD 630
Software: Emby 4.7.4.0
Modules enabled:
coretemp
vfio
vfio_iommu_type1
vfio_pci
vfio_virqfd
kvmgt
GRUB_CMDLINE_LINUX_DEFAULT="quiet intel_iommu=on iommu=pt i915.enable_gvt=1 video=efifb:off"