Okay, let's see. The user is reporting that QEMU-user doesn't report HWCAP2_MTE. They provided a test case where compiling a specific C program and running it under QEMU results in 0 instead of the expected non-zero value. The categories to choose from are instruction, syscall, or runtime. First, I need to understand what HWCAP2_MTE is. From the code, HWCAP2_MTE is defined as (1 << 18). Looking up ARM's HWCAP flags, HWCAP2 is the second set of hardware capabilities, and MTE (Memory Tagging Extension) is a feature available in some ARMv8 variants. So HWCAP2_MTE indicates whether the CPU supports the Memory Tagging Extension. The test program uses getauxval(AT_HWCAP2) to check if the MTE bit is set. When they run it under QEMU with --cpu max, which should enable all features, it's returning 0. The problem is that QEMU isn't advertising the MTE support in the HWCAP2 flags for user-mode emulation. Now, categorizing the bug. The options are instruction, syscall, or runtime. The instruction category would be if the issue is due to incorrect execution of a specific instruction. The syscall category is for issues related to system calls. The runtime category is for other runtime errors. In this case, the issue is about QEMU not correctly reporting a hardware capability flag. The getauxval function is a system call, but the problem isn't with the system call itself. Instead, it's about how QEMU emulates the hardware capabilities. The HWCAP2 is part of the auxiliary vector provided by the kernel, which QEMU's user-mode emulation is responsible for generating. If QEMU isn't setting the correct HWCAP2 flags, that's a runtime issue because it's about the environment setup during execution. It's not a specific instruction being mishandled, nor is it a direct syscall error. So the correct category is runtime. runtime