Alright, I need to figure out whether this bug is user-mode or system-mode related. The problem is that old Ubuntu amd64 live CDs won't boot in QEMU-system-x86_64, but i386 ones do. It started breaking around QEMU 7.1.0 and seems to affect AMD processors. So, let's break this down. User-mode issues are typically related to applications running under the user's privileges, while system-mode involves lower-level things like hardware interaction, device drivers, or emulated environments that require higher privileges. In this case, QEMU is a system emulator, so it operates at a lower level, interacting with virtualized hardware components. The panic during boot suggests an issue with how the virtual machine is handling certain instructions or hardware emulation. The fact that it works on Intel but not AMD could indicate problems with how QEMU handles AMD-specific features in newer versions. Since this involves emulating a CPU and dealing with lower-level exceptions, it's more about system-mode operations rather than user applications. Therefore, this bug is likely related to the system-mode functionality of QEMU. system