Queued TCG patches

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Merge remote-tracking branch 'remotes/rth/tags/pull-tcg-20170603' into staging

Queued TCG patches

# gpg: Signature made Fri 30 Jun 2017 20:03:53 BST
# gpg:                using RSA key 0xAD1270CC4DD0279B
# gpg: Good signature from "Richard Henderson <rth7680@gmail.com>"
# gpg:                 aka "Richard Henderson <rth@redhat.com>"
# gpg:                 aka "Richard Henderson <rth@twiddle.net>"
# Primary key fingerprint: 9CB1 8DDA F8E8 49AD 2AFC  16A4 AD12 70CC 4DD0 279B

* remotes/rth/tags/pull-tcg-20170603:
  tcg: consistently access cpu->tb_jmp_cache atomically
  gen-icount: use tcg_ctx.tcg_env instead of cpu_env
  gen-icount: add missing inline to gen_tb_end

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

accel/tcg/cputlb.c

@@ -118,7 +118,7 @@ static void tlb_flush_nocheck(CPUState *cpu)
 
     memset(env->tlb_table, -1, sizeof(env->tlb_table));
     memset(env->tlb_v_table, -1, sizeof(env->tlb_v_table));
-    memset(cpu->tb_jmp_cache, 0, sizeof(cpu->tb_jmp_cache));
+    cpu_tb_jmp_cache_clear(cpu);
 
     env->vtlb_index = 0;
     env->tlb_flush_addr = -1;
@@ -183,7 +183,7 @@ static void tlb_flush_by_mmuidx_async_work(CPUState *cpu, run_on_cpu_data data)
         }
     }
 
-    memset(cpu->tb_jmp_cache, 0, sizeof(cpu->tb_jmp_cache));
+    cpu_tb_jmp_cache_clear(cpu);
 
     tlb_debug("done\n");
 

accel/tcg/translate-all.c

@@ -928,11 +928,7 @@ static void do_tb_flush(CPUState *cpu, run_on_cpu_data tb_flush_count)
     }
 
     CPU_FOREACH(cpu) {
-        int i;
+        cpu_tb_jmp_cache_clear(cpu);
-
-        for (i = 0; i < TB_JMP_CACHE_SIZE; ++i) {
-            atomic_set(&cpu->tb_jmp_cache[i], NULL);
-        }
     }
 
     tcg_ctx.tb_ctx.nb_tbs = 0;
@@ -1813,19 +1809,21 @@ void cpu_io_recompile(CPUState *cpu, uintptr_t retaddr)
     cpu_loop_exit_noexc(cpu);
 }
 
+static void tb_jmp_cache_clear_page(CPUState *cpu, target_ulong page_addr)
+{
+    unsigned int i, i0 = tb_jmp_cache_hash_page(page_addr);
+
+    for (i = 0; i < TB_JMP_PAGE_SIZE; i++) {
+        atomic_set(&cpu->tb_jmp_cache[i0 + i], NULL);
+    }
+}
+
 void tb_flush_jmp_cache(CPUState *cpu, target_ulong addr)
 {
-    unsigned int i;
-
     /* Discard jump cache entries for any tb which might potentially
        overlap the flushed page.  */
-    i = tb_jmp_cache_hash_page(addr - TARGET_PAGE_SIZE);
+    tb_jmp_cache_clear_page(cpu, addr - TARGET_PAGE_SIZE);
-    memset(&cpu->tb_jmp_cache[i], 0,
+    tb_jmp_cache_clear_page(cpu, addr);
-           TB_JMP_PAGE_SIZE * sizeof(TranslationBlock *));
-
-    i = tb_jmp_cache_hash_page(addr);
-    memset(&cpu->tb_jmp_cache[i], 0,
-           TB_JMP_PAGE_SIZE * sizeof(TranslationBlock *));
 }
 
 static void print_qht_statistics(FILE *f, fprintf_function cpu_fprintf,

include/exec/gen-icount.h

@@ -19,7 +19,7 @@ static inline void gen_tb_start(TranslationBlock *tb)
         count = tcg_temp_new_i32();
     }
 
-    tcg_gen_ld_i32(count, cpu_env,
+    tcg_gen_ld_i32(count, tcg_ctx.tcg_env,
                    -ENV_OFFSET + offsetof(CPUState, icount_decr.u32));
 
     if (tb->cflags & CF_USE_ICOUNT) {
@@ -37,14 +37,14 @@ static inline void gen_tb_start(TranslationBlock *tb)
     tcg_gen_brcondi_i32(TCG_COND_LT, count, 0, exitreq_label);
 
     if (tb->cflags & CF_USE_ICOUNT) {
-        tcg_gen_st16_i32(count, cpu_env,
+        tcg_gen_st16_i32(count, tcg_ctx.tcg_env,
                          -ENV_OFFSET + offsetof(CPUState, icount_decr.u16.low));
     }
 
     tcg_temp_free_i32(count);
 }
 
-static void gen_tb_end(TranslationBlock *tb, int num_insns)
+static inline void gen_tb_end(TranslationBlock *tb, int num_insns)
 {
     if (tb->cflags & CF_USE_ICOUNT) {
         /* Update the num_insn immediate parameter now that we know
@@ -62,14 +62,16 @@ static void gen_tb_end(TranslationBlock *tb, int num_insns)
 static inline void gen_io_start(void)
 {
     TCGv_i32 tmp = tcg_const_i32(1);
-    tcg_gen_st_i32(tmp, cpu_env, -ENV_OFFSET + offsetof(CPUState, can_do_io));
+    tcg_gen_st_i32(tmp, tcg_ctx.tcg_env,
+                   -ENV_OFFSET + offsetof(CPUState, can_do_io));
     tcg_temp_free_i32(tmp);
 }
 
 static inline void gen_io_end(void)
 {
     TCGv_i32 tmp = tcg_const_i32(0);
-    tcg_gen_st_i32(tmp, cpu_env, -ENV_OFFSET + offsetof(CPUState, can_do_io));
+    tcg_gen_st_i32(tmp, tcg_ctx.tcg_env,
+                   -ENV_OFFSET + offsetof(CPUState, can_do_io));
     tcg_temp_free_i32(tmp);
 }
 

include/qom/cpu.h

@@ -346,7 +346,7 @@ struct CPUState {
 
     void *env_ptr; /* CPUArchState */
 
-    /* Writes protected by tb_lock, reads not thread-safe  */
+    /* Accessed in parallel; all accesses must be atomic */
     struct TranslationBlock *tb_jmp_cache[TB_JMP_CACHE_SIZE];
 
     struct GDBRegisterState *gdb_regs;
@@ -422,6 +422,15 @@ extern struct CPUTailQ cpus;
 
 extern __thread CPUState *current_cpu;
 
+static inline void cpu_tb_jmp_cache_clear(CPUState *cpu)
+{
+    unsigned int i;
+
+    for (i = 0; i < TB_JMP_CACHE_SIZE; i++) {
+        atomic_set(&cpu->tb_jmp_cache[i], NULL);
+    }
+}
+
 /**
  * qemu_tcg_mttcg_enabled:
  * Check whether we are running MultiThread TCG or not.

qom/cpu.c

@@ -274,7 +274,6 @@ void cpu_reset(CPUState *cpu)
 static void cpu_common_reset(CPUState *cpu)
 {
     CPUClass *cc = CPU_GET_CLASS(cpu);
-    int i;
 
     if (qemu_loglevel_mask(CPU_LOG_RESET)) {
         qemu_log("CPU Reset (CPU %d)\n", cpu->cpu_index);
@@ -292,9 +291,7 @@ static void cpu_common_reset(CPUState *cpu)
     cpu->crash_occurred = false;
 
     if (tcg_enabled()) {
-        for (i = 0; i < TB_JMP_CACHE_SIZE; ++i) {
+        cpu_tb_jmp_cache_clear(cpu);
-            atomic_set(&cpu->tb_jmp_cache[i], NULL);
-        }
 
 #ifdef CONFIG_SOFTMMU
         tlb_flush(cpu, 0);