diff options
| -rw-r--r-- | target/arm/op_helper.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/target/arm/op_helper.c b/target/arm/op_helper.c index 78b831f181..efcb600992 100644 --- a/target/arm/op_helper.c +++ b/target/arm/op_helper.c @@ -228,6 +228,7 @@ void HELPER(setend)(CPUARMState *env) arm_rebuild_hflags(env); } +#ifndef CONFIG_USER_ONLY /* Function checks whether WFx (WFI/WFE) instructions are set up to be trapped. * The function returns the target EL (1-3) if the instruction is to be trapped; * otherwise it returns 0 indicating it is not trapped. @@ -282,9 +283,21 @@ static inline int check_wfx_trap(CPUARMState *env, bool is_wfe) return 0; } +#endif void HELPER(wfi)(CPUARMState *env, uint32_t insn_len) { +#ifdef CONFIG_USER_ONLY + /* + * WFI in the user-mode emulator is technically permitted but not + * something any real-world code would do. AArch64 Linux kernels + * trap it via SCTRL_EL1.nTWI and make it an (expensive) NOP; + * AArch32 kernels don't trap it so it will delay a bit. + * For QEMU, make it NOP here, because trying to raise EXCP_HLT + * would trigger an abort. + */ + return; +#else CPUState *cs = env_cpu(env); int target_el = check_wfx_trap(env, false); @@ -309,6 +322,7 @@ void HELPER(wfi)(CPUARMState *env, uint32_t insn_len) cs->exception_index = EXCP_HLT; cs->halted = 1; cpu_loop_exit(cs); +#endif } void HELPER(wfe)(CPUARMState *env) |