Okay, I need to figure out whether this bug report is about user-mode or system-mode in QEMU. The issue is that setting HCR.TVM to 1 doesn't trap certain writes on AARCH64 as it should. HCR stands for Hypervisor Control Register, which is a system register. When TVM is set, it's supposed to trap specific accesses in the translation and memory system registers. These are things like CTXIDR_EL1, TCR_EL1, etc., all of which are system-level registers used by the OS or hypervisor for managing page tables and memory. Since this involves modifying hypervisor control and trapping writes at a low level, it's definitely dealing with higher privilege levels—like when an operating system is running in EL1 (kernel mode) or a hypervisor in EL2. This isn't something a user-mode application would handle; those typically can't access such registers without permissions. QEMU is the emulator here, and if it's not handling HCR.TVM correctly, that affects how the virtual machine runs at a system level. It relates to how the CPU emulates these control structures, which are critical for things like memory management and virtualization in the OS or hypervisor. So, because this involves higher privilege levels, system registers, and impacts how the operating system interacts with the hardware (or emulator), it's a system-mode issue. system