>From 6ce760bc19546e4d139732e9a5eb44b578dd834b Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Wed, 29 Jun 2016 22:12:55 -0700 Subject: [PATCH v7 06/35] tcg: Add EXCP_ATOMIC MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When we cannot emulate an atomic operation within a parallel context, this exception allows us to stop the world and try again in a serial context. Reviewed-by: Emilio G. Cota Reviewed-by: Alex Bennée Signed-off-by: Richard Henderson --- cpu-exec-common.c | 6 ++++++ cpu-exec.c | 30 ++++++++++++++++++++++++++++++ cpus.c | 2 ++ include/exec/cpu-all.h | 1 + include/exec/exec-all.h | 1 + include/qemu-common.h | 1 + linux-user/main.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ tcg/tcg.h | 1 + translate-all.c | 1 + 9 files changed, 88 insertions(+) diff --git a/cpu-exec-common.c b/cpu-exec-common.c index 0cb4ae6..767d9c6 100644 --- a/cpu-exec-common.c +++ b/cpu-exec-common.c @@ -77,3 +77,9 @@ void cpu_loop_exit_restore(CPUState *cpu, uintptr_t pc) } siglongjmp(cpu->jmp_env, 1); } + +void cpu_loop_exit_atomic(CPUState *cpu, uintptr_t pc) +{ + cpu->exception_index = EXCP_ATOMIC; + cpu_loop_exit_restore(cpu, pc); +} diff --git a/cpu-exec.c b/cpu-exec.c index e114fcd..c999793 100644 --- a/cpu-exec.c +++ b/cpu-exec.c @@ -222,6 +222,36 @@ static void cpu_exec_nocache(CPUState *cpu, int max_cycles, } #endif +static void cpu_exec_step(CPUState *cpu) +{ + CPUArchState *env = (CPUArchState *)cpu->env_ptr; + TranslationBlock *tb; + target_ulong cs_base, pc; + uint32_t flags; + + cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags); + tb = tb_gen_code(cpu, pc, cs_base, flags, + 1 | CF_NOCACHE | CF_IGNORE_ICOUNT); + tb->orig_tb = NULL; + /* execute the generated code */ + trace_exec_tb_nocache(tb, pc); + cpu_tb_exec(cpu, tb); + tb_phys_invalidate(tb, -1); + tb_free(tb); +} + +void cpu_exec_step_atomic(CPUState *cpu) +{ + start_exclusive(); + + /* Since we got here, we know that parallel_cpus must be true. */ + parallel_cpus = false; + cpu_exec_step(cpu); + parallel_cpus = true; + + end_exclusive(); +} + struct tb_desc { target_ulong pc; target_ulong cs_base; diff --git a/cpus.c b/cpus.c index 31204bb..cfd5cdc 100644 --- a/cpus.c +++ b/cpus.c @@ -1497,6 +1497,8 @@ static void tcg_exec_all(void) if (r == EXCP_DEBUG) { cpu_handle_guest_debug(cpu); break; + } else if (r == EXCP_ATOMIC) { + cpu_exec_step_atomic(cpu); } } else if (cpu->stop || cpu->stopped) { if (cpu->unplug) { diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h index b6a7059..1f7e9d8 100644 --- a/include/exec/cpu-all.h +++ b/include/exec/cpu-all.h @@ -31,6 +31,7 @@ #define EXCP_DEBUG 0x10002 /* cpu stopped after a breakpoint or singlestep */ #define EXCP_HALTED 0x10003 /* cpu is halted (waiting for external event) */ #define EXCP_YIELD 0x10004 /* cpu wants to yield timeslice to another */ +#define EXCP_ATOMIC 0x10005 /* stop-the-world and emulate atomic */ /* some important defines: * diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h index 336a57c..13633a2 100644 --- a/include/exec/exec-all.h +++ b/include/exec/exec-all.h @@ -60,6 +60,7 @@ TranslationBlock *tb_gen_code(CPUState *cpu, void cpu_exec_init(CPUState *cpu, Error **errp); void QEMU_NORETURN cpu_loop_exit(CPUState *cpu); void QEMU_NORETURN cpu_loop_exit_restore(CPUState *cpu, uintptr_t pc); +void QEMU_NORETURN cpu_loop_exit_atomic(CPUState *cpu, uintptr_t pc); #if !defined(CONFIG_USER_ONLY) void cpu_reloading_memory_map(void); diff --git a/include/qemu-common.h b/include/qemu-common.h index 9e8b0bd..291f98d 100644 --- a/include/qemu-common.h +++ b/include/qemu-common.h @@ -80,6 +80,7 @@ void tcg_exec_init(unsigned long tb_size); bool tcg_enabled(void); void cpu_exec_init_all(void); +void cpu_exec_step_atomic(CPUState *cpu); /** * Sends a (part of) iovec down a socket, yielding when the socket is full, or diff --git a/linux-user/main.c b/linux-user/main.c index 0e31dad..a6406ce 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -354,6 +354,9 @@ void cpu_loop(CPUX86State *env) } } break; + case EXCP_ATOMIC: + cpu_exec_step_atomic(cs); + break; default: pc = env->segs[R_CS].base + env->eip; EXCP_DUMP(env, "qemu: 0x%08lx: unhandled CPU exception 0x%x - aborting\n", @@ -848,6 +851,9 @@ void cpu_loop(CPUARMState *env) case EXCP_YIELD: /* nothing to do here for user-mode, just resume guest code */ break; + case EXCP_ATOMIC: + cpu_exec_step_atomic(cs); + break; default: error: EXCP_DUMP(env, "qemu: unhandled CPU exception 0x%x - aborting\n", trapnr); @@ -1048,6 +1054,9 @@ void cpu_loop(CPUARMState *env) case EXCP_YIELD: /* nothing to do here for user-mode, just resume guest code */ break; + case EXCP_ATOMIC: + cpu_exec_step_atomic(cs); + break; default: EXCP_DUMP(env, "qemu: unhandled CPU exception 0x%x - aborting\n", trapnr); abort(); @@ -1139,6 +1148,9 @@ void cpu_loop(CPUUniCore32State *env) } } break; + case EXCP_ATOMIC: + cpu_exec_step_atomic(cs); + break; default: goto error; } @@ -1412,6 +1424,9 @@ void cpu_loop (CPUSPARCState *env) } } break; + case EXCP_ATOMIC: + cpu_exec_step_atomic(cs); + break; default: printf ("Unhandled trap: 0x%x\n", trapnr); cpu_dump_state(cs, stderr, fprintf, 0); @@ -1951,6 +1966,9 @@ void cpu_loop(CPUPPCState *env) case EXCP_INTERRUPT: /* just indicate that signals should be handled asap */ break; + case EXCP_ATOMIC: + cpu_exec_step_atomic(cs); + break; default: cpu_abort(cs, "Unknown exception 0x%x. Aborting\n", trapnr); break; @@ -2626,6 +2644,9 @@ done_syscall: } } break; + case EXCP_ATOMIC: + cpu_exec_step_atomic(cs); + break; default: error: EXCP_DUMP(env, "qemu: unhandled CPU exception 0x%x - aborting\n", trapnr); @@ -2713,6 +2734,9 @@ void cpu_loop(CPUOpenRISCState *env) case EXCP_NR: qemu_log_mask(CPU_LOG_INT, "\nNR\n"); break; + case EXCP_ATOMIC: + cpu_exec_step_atomic(cs); + break; default: EXCP_DUMP(env, "\nqemu: unhandled CPU exception %#x - aborting\n", trapnr); @@ -2789,6 +2813,9 @@ void cpu_loop(CPUSH4State *env) queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); break; + case EXCP_ATOMIC: + cpu_exec_step_atomic(cs); + break; default: printf ("Unhandled trap: 0x%x\n", trapnr); cpu_dump_state(cs, stderr, fprintf, 0); @@ -2856,6 +2883,9 @@ void cpu_loop(CPUCRISState *env) } } break; + case EXCP_ATOMIC: + cpu_exec_step_atomic(cs); + break; default: printf ("Unhandled trap: 0x%x\n", trapnr); cpu_dump_state(cs, stderr, fprintf, 0); @@ -2972,6 +3002,9 @@ void cpu_loop(CPUMBState *env) } } break; + case EXCP_ATOMIC: + cpu_exec_step_atomic(cs); + break; default: printf ("Unhandled trap: 0x%x\n", trapnr); cpu_dump_state(cs, stderr, fprintf, 0); @@ -3075,6 +3108,9 @@ void cpu_loop(CPUM68KState *env) } } break; + case EXCP_ATOMIC: + cpu_exec_step_atomic(cs); + break; default: EXCP_DUMP(env, "qemu: unhandled CPU exception 0x%x - aborting\n", trapnr); abort(); @@ -3311,6 +3347,9 @@ void cpu_loop(CPUAlphaState *env) case EXCP_INTERRUPT: /* Just indicate that signals should be handled asap. */ break; + case EXCP_ATOMIC: + cpu_exec_step_atomic(cs); + break; default: printf ("Unhandled trap: 0x%x\n", trapnr); cpu_dump_state(cs, stderr, fprintf, 0); @@ -3440,6 +3479,9 @@ void cpu_loop(CPUS390XState *env) queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); break; + case EXCP_ATOMIC: + cpu_exec_step_atomic(cs); + break; default: fprintf(stderr, "Unhandled trap: 0x%x\n", trapnr); cpu_dump_state(cs, stderr, fprintf, 0); @@ -3694,6 +3736,9 @@ void cpu_loop(CPUTLGState *env) case TILEGX_EXCP_REG_UDN_ACCESS: gen_sigill_reg(env); break; + case EXCP_ATOMIC: + cpu_exec_step_atomic(cs); + break; default: fprintf(stderr, "trapnr is %d[0x%x].\n", trapnr, trapnr); g_assert_not_reached(); diff --git a/tcg/tcg.h b/tcg/tcg.h index c9949aa..3b21156 100644 --- a/tcg/tcg.h +++ b/tcg/tcg.h @@ -704,6 +704,7 @@ struct TCGContext { }; extern TCGContext tcg_ctx; +extern bool parallel_cpus; static inline void tcg_set_insn_param(int op_idx, int arg, TCGArg v) { diff --git a/translate-all.c b/translate-all.c index 8ca393c..4200869 100644 --- a/translate-all.c +++ b/translate-all.c @@ -119,6 +119,7 @@ static void *l1_map[V_L1_SIZE]; /* code generation context */ TCGContext tcg_ctx; +bool parallel_cpus; /* translation block context */ #ifdef CONFIG_USER_ONLY -- 2.7.4