Okay, I need to figure out whether this bug is user-mode or system-mode related based on the provided information. The issue is about running aarch64 Docker containers on an x86_64 host where video devices (/dev/video*) aren't working properly. The error message mentions "Function not implemented" when trying to access /dev/video0, and another error with an ioctl command. Looking at the setup: the guest OS is aarch64 running inside Docker using QEMU for emulation. They're trying to use video devices which are passed through from the host. Since the problem occurs during device access (ioctl) on a device file (/dev/video*), this suggests it's related to how the system handles device drivers and ioctl commands in the emulated environment. The qemu-user-static is involved, but since it's about device emulation or driver support, it might be more of a system-level issue. Moreover, the fact that they're using --privileged mode and binding /dev/video0 indicates that this involves low-level device access which is typically handled at the kernel level. Therefore, it's likely a system-mode problem because it relates to device drivers and ioctl handling in the emulated environment, not just userland applications. system