diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index 2c34adccce..99ca6f36b9 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -60,6 +60,7 @@ #include "sysemu/cpu-timers.h" #include "sysemu/tcg.h" #include "qapi/error.h" +#include "hw/core/tcg-cpu-ops.h" #include "internal.h" /* #define DEBUG_TB_INVALIDATE */ @@ -2421,6 +2422,7 @@ void cpu_io_recompile(CPUState *cpu, uintptr_t retaddr) CPUArchState *env = cpu->env_ptr; #endif TranslationBlock *tb; + CPUClass *cc; uint32_t n; tb = tcg_tb_lookup(retaddr); @@ -2430,11 +2432,18 @@ void cpu_io_recompile(CPUState *cpu, uintptr_t retaddr) } cpu_restore_state_from_tb(cpu, tb, retaddr, true); - /* On MIPS and SH, delay slot instructions can only be restarted if - they were already the first instruction in the TB. If this is not - the first instruction in a TB then re-execute the preceding - branch. */ + /* + * Some guests must re-execute the branch when re-executing a delay + * slot instruction. When this is the case, adjust icount and N + * to account for the re-execution of the branch. + */ n = 1; + cc = CPU_GET_CLASS(cpu); + if (cc->tcg_ops->io_recompile_replay_branch && + cc->tcg_ops->io_recompile_replay_branch(cpu, tb)) { + cpu_neg(cpu)->icount_decr.u16.low++; + n = 2; + } #if defined(TARGET_MIPS) if ((env->hflags & MIPS_HFLAG_BMASK) != 0 && env->active_tc.PC != tb->pc) { diff --git a/include/hw/core/tcg-cpu-ops.h b/include/hw/core/tcg-cpu-ops.h index ac3bb051f2..72d791438c 100644 --- a/include/hw/core/tcg-cpu-ops.h +++ b/include/hw/core/tcg-cpu-ops.h @@ -88,6 +88,16 @@ struct TCGCPUOps { */ bool (*debug_check_watchpoint)(CPUState *cpu, CPUWatchpoint *wp); + /** + * @io_recompile_replay_branch: Callback for cpu_io_recompile. + * + * The cpu has been stopped, and cpu_restore_state_from_tb has been + * called. If the faulting instruction is in a delay slot, and the + * target architecture requires re-execution of the branch, then + * adjust the cpu state as required and return true. + */ + bool (*io_recompile_replay_branch)(CPUState *cpu, + const TranslationBlock *tb); #endif /* CONFIG_SOFTMMU */ #endif /* NEED_CPU_H */