Okay, so I need to classify this bug report about the aarch64 register MDCCINT_EL1 into either 'user-mode' or 'system-mode'. The user mentioned that the behavior is bizarre in QEMU. First, I should understand what MDCCINT_EL1 is. From what I know, EL1 refers to Exception Level 1 in ARM's architecture, which is typically the operating system level, also known as supervisor mode. This suggests it's a system-level register rather than something used by user applications. MDCCINT_EL1 stands for Memory Data Cache Cleaner Instruction Counter El1. It counts the number of cache cleaning operations initiated by software at EL1. Since EL1 is a higher privilege level, this register is likely involved in system operations, maybe handling memory management or performance monitoring. The bug report talks about QEMU exhibiting bizarre behavior with this register. QEMU handles both user and system emulation. But since MDCCINT_EL1 is related to exception levels and cache operations at the OS level, it's more about system-mode aspects like peripherals, devices, and operating systems. So putting it all together, this bug seems to be in the system-mode part of QEMU because it involves a higher privilege register used for system functions. system