diff options
| -rw-r--r-- | cpu-exec.c | 59 | ||||
| -rw-r--r-- | tcg/tcg.h | 19 | ||||
| -rw-r--r-- | tci.c | 6 | ||||
| -rw-r--r-- | trace-events | 2 |
4 files changed, 46 insertions, 40 deletions
@@ -136,7 +136,9 @@ static void init_delay_params(SyncClocks *sc, const CPUState *cpu) static inline tcg_target_ulong cpu_tb_exec(CPUState *cpu, TranslationBlock *itb) { CPUArchState *env = cpu->env_ptr; - uintptr_t next_tb; + uintptr_t ret; + TranslationBlock *last_tb; + int tb_exit; uint8_t *tb_ptr = itb->tc_ptr; qemu_log_mask_and_addr(CPU_LOG_EXEC, itb->pc, @@ -160,36 +162,37 @@ static inline tcg_target_ulong cpu_tb_exec(CPUState *cpu, TranslationBlock *itb) #endif /* DEBUG_DISAS */ cpu->can_do_io = !use_icount; - next_tb = tcg_qemu_tb_exec(env, tb_ptr); + ret = tcg_qemu_tb_exec(env, tb_ptr); cpu->can_do_io = 1; - trace_exec_tb_exit((void *) (next_tb & ~TB_EXIT_MASK), - next_tb & TB_EXIT_MASK); + last_tb = (TranslationBlock *)(ret & ~TB_EXIT_MASK); + tb_exit = ret & TB_EXIT_MASK; + trace_exec_tb_exit(last_tb, tb_exit); - if ((next_tb & TB_EXIT_MASK) > TB_EXIT_IDX1) { + if (tb_exit > TB_EXIT_IDX1) { /* We didn't start executing this TB (eg because the instruction * counter hit zero); we must restore the guest PC to the address * of the start of the TB. */ CPUClass *cc = CPU_GET_CLASS(cpu); - TranslationBlock *tb = (TranslationBlock *)(next_tb & ~TB_EXIT_MASK); - qemu_log_mask_and_addr(CPU_LOG_EXEC, itb->pc, + qemu_log_mask_and_addr(CPU_LOG_EXEC, last_tb->pc, "Stopped execution of TB chain before %p [" TARGET_FMT_lx "] %s\n", - itb->tc_ptr, itb->pc, lookup_symbol(itb->pc)); + last_tb->tc_ptr, last_tb->pc, + lookup_symbol(last_tb->pc)); if (cc->synchronize_from_tb) { - cc->synchronize_from_tb(cpu, tb); + cc->synchronize_from_tb(cpu, last_tb); } else { assert(cc->set_pc); - cc->set_pc(cpu, tb->pc); + cc->set_pc(cpu, last_tb->pc); } } - if ((next_tb & TB_EXIT_MASK) == TB_EXIT_REQUESTED) { + if (tb_exit == TB_EXIT_REQUESTED) { /* We were asked to stop executing TBs (probably a pending * interrupt. We've now stopped, so clear the flag. */ cpu->tcg_exit_req = 0; } - return next_tb; + return ret; } #ifndef CONFIG_USER_ONLY @@ -358,8 +361,8 @@ int cpu_exec(CPUState *cpu) CPUArchState *env = &x86_cpu->env; #endif int ret, interrupt_request; - TranslationBlock *tb; - uintptr_t next_tb; + TranslationBlock *tb, *last_tb; + int tb_exit = 0; SyncClocks sc; /* replay_interrupt may need current_cpu */ @@ -442,7 +445,7 @@ int cpu_exec(CPUState *cpu) #endif } - next_tb = 0; /* force lookup of first TB */ + last_tb = NULL; /* forget the last executed TB after exception */ for(;;) { interrupt_request = cpu->interrupt_request; if (unlikely(interrupt_request)) { @@ -487,7 +490,7 @@ int cpu_exec(CPUState *cpu) else { replay_interrupt(); if (cc->cpu_exec_interrupt(cpu, interrupt_request)) { - next_tb = 0; + last_tb = NULL; } } /* Don't use the cached interrupt_request value, @@ -496,7 +499,7 @@ int cpu_exec(CPUState *cpu) cpu->interrupt_request &= ~CPU_INTERRUPT_EXITTB; /* ensure that no TB jump will be modified as the program flow was changed */ - next_tb = 0; + last_tb = NULL; } } if (unlikely(cpu->exit_request @@ -513,22 +516,24 @@ int cpu_exec(CPUState *cpu) /* as some TB could have been invalidated because of memory exceptions while generating the code, we must recompute the hash index here */ - next_tb = 0; + last_tb = NULL; tcg_ctx.tb_ctx.tb_invalidated_flag = 0; } /* See if we can patch the calling TB. */ - if (next_tb != 0 && !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) { - tb_add_jump((TranslationBlock *)(next_tb & ~TB_EXIT_MASK), - next_tb & TB_EXIT_MASK, tb); + if (last_tb && !qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) { + tb_add_jump(last_tb, tb_exit, tb); } tb_unlock(); if (likely(!cpu->exit_request)) { + uintptr_t ret; trace_exec_tb(tb, tb->pc); /* execute the generated code */ cpu->current_tb = tb; - next_tb = cpu_tb_exec(cpu, tb); + ret = cpu_tb_exec(cpu, tb); cpu->current_tb = NULL; - switch (next_tb & TB_EXIT_MASK) { + last_tb = (TranslationBlock *)(ret & ~TB_EXIT_MASK); + tb_exit = ret & TB_EXIT_MASK; + switch (tb_exit) { case TB_EXIT_REQUESTED: /* Something asked us to stop executing * chained TBs; just continue round the main @@ -541,7 +546,7 @@ int cpu_exec(CPUState *cpu) * or cpu->interrupt_request. */ smp_rmb(); - next_tb = 0; + last_tb = NULL; break; case TB_EXIT_ICOUNT_EXPIRED: { @@ -559,12 +564,12 @@ int cpu_exec(CPUState *cpu) } else { if (insns_left > 0) { /* Execute remaining instructions. */ - tb = (TranslationBlock *)(next_tb & ~TB_EXIT_MASK); - cpu_exec_nocache(cpu, insns_left, tb, false); + cpu_exec_nocache(cpu, insns_left, + last_tb, false); align_clocks(&sc, cpu); } cpu->exception_index = EXCP_INTERRUPT; - next_tb = 0; + last_tb = NULL; cpu_loop_exit(cpu); } break; @@ -925,7 +925,7 @@ static inline unsigned get_mmuidx(TCGMemOpIdx oi) /** * tcg_qemu_tb_exec: - * @env: CPUArchState * for the CPU + * @env: pointer to CPUArchState for the CPU * @tb_ptr: address of generated code for the TB to execute * * Start executing code from a given translation block. @@ -936,30 +936,31 @@ static inline unsigned get_mmuidx(TCGMemOpIdx oi) * which has not yet been directly linked, or an asynchronous * event such as an interrupt needs handling. * - * The return value is a pointer to the next TB to execute - * (if known; otherwise zero). This pointer is assumed to be - * 4-aligned, and the bottom two bits are used to return further - * information: + * Return: The return value is the value passed to the corresponding + * tcg_gen_exit_tb() at translation time of the last TB attempted to execute. + * The value is either zero or a 4-byte aligned pointer to that TB combined + * with additional information in its two least significant bits. The + * additional information is encoded as follows: * 0, 1: the link between this TB and the next is via the specified * TB index (0 or 1). That is, we left the TB via (the equivalent * of) "goto_tb <index>". The main loop uses this to determine * how to link the TB just executed to the next. * 2: we are using instruction counting code generation, and we * did not start executing this TB because the instruction counter - * would hit zero midway through it. In this case the next-TB pointer + * would hit zero midway through it. In this case the pointer * returned is the TB we were about to execute, and the caller must * arrange to execute the remaining count of instructions. * 3: we stopped because the CPU's exit_request flag was set * (usually meaning that there is an interrupt that needs to be - * handled). The next-TB pointer returned is the TB we were - * about to execute when we noticed the pending exit request. + * handled). The pointer returned is the TB we were about to execute + * when we noticed the pending exit request. * * If the bottom two bits indicate an exit-via-index then the CPU * state is correctly synchronised and ready for execution of the next * TB (and in particular the guest PC is the address to execute next). * Otherwise, we gave up on execution of this TB before it started, and * the caller must fix up the CPU state by calling the CPU's - * synchronize_from_tb() method with the next-TB pointer we return (falling + * synchronize_from_tb() method with the TB pointer we return (falling * back to calling the CPU's set_pc method with tb->pb if no * synchronize_from_tb() method exists). * @@ -467,7 +467,7 @@ uintptr_t tcg_qemu_tb_exec(CPUArchState *env, uint8_t *tb_ptr) { long tcg_temps[CPU_TEMP_BUF_NLONGS]; uintptr_t sp_value = (uintptr_t)(tcg_temps + CPU_TEMP_BUF_NLONGS); - uintptr_t next_tb = 0; + uintptr_t ret = 0; tci_reg[TCG_AREG0] = (tcg_target_ulong)env; tci_reg[TCG_REG_CALL_STACK] = sp_value; @@ -1085,7 +1085,7 @@ uintptr_t tcg_qemu_tb_exec(CPUArchState *env, uint8_t *tb_ptr) /* QEMU specific operations. */ case INDEX_op_exit_tb: - next_tb = *(uint64_t *)tb_ptr; + ret = *(uint64_t *)tb_ptr; goto exit; break; case INDEX_op_goto_tb: @@ -1243,5 +1243,5 @@ uintptr_t tcg_qemu_tb_exec(CPUArchState *env, uint8_t *tb_ptr) tci_assert(tb_ptr == old_code_ptr + op_size); } exit: - return next_tb; + return ret; } diff --git a/trace-events b/trace-events index b588091..4fce005 100644 --- a/trace-events +++ b/trace-events @@ -1614,7 +1614,7 @@ kvm_failed_spr_get(int str, const char *msg) "Warning: Unable to retrieve SPR %d # cpu-exec.c disable exec_tb(void *tb, uintptr_t pc) "tb:%p pc=0x%"PRIxPTR disable exec_tb_nocache(void *tb, uintptr_t pc) "tb:%p pc=0x%"PRIxPTR -disable exec_tb_exit(void *next_tb, unsigned int flags) "tb:%p flags=%x" +disable exec_tb_exit(void *last_tb, unsigned int flags) "tb:%p flags=%x" # translate-all.c translate_block(void *tb, uintptr_t pc, uint8_t *tb_code) "tb:%p, pc:0x%"PRIxPTR", tb_code:%p" |