Okay, so I'm trying to figure out whether this QEMU issue is a user-mode or system-mode problem. Let me break down the information given. The user reports that when they execute an `icebp` instruction (which is opcode F1), QEMU raises `SIGILL` instead of `SIGTRAP`. On baremetal Linux, it correctly raises `SIGTRAP`, which makes sense because `icebp` generates a debug exception (#DB) without changing the DR6 register. The user provided steps to reproduce using a simple assembly program that just runs `icebp` and then exits. When run on QEMU, it throws an illegal instruction signal (SIGILL), whereas on actual hardware or baremetal, it's treated as a trap signal (SIGTRAP). Now, thinking about how QEMU works: in user-mode emulation, QEMU translates guest instructions into host instructions. It handles signals and exceptions by translating them into the appropriate signals for the host environment. The problem here is that `icebp` is being translated to SIGILL in QEMU but should be SIGTRAP. That suggests an issue with how QEMU's user-mode emulator (qemu-user) is handling this specific instruction. Since this issue arises when running a program through qemu-user, which emulates the user space of another architecture on the host, it's likely related to user-mode emulation rather than system-mode where QEMU would be emulating an entire OS and hardware setup. So, because the problem occurs in how signals are being handled for a user-space instruction, this bug is classified under 'user' mode. user