target-*: Introduce and use cpu_breakpoint_test

Reduce the boilerplate required for each target. At the same time,
move the test for breakpoint after calling tcg_gen_insn_start.

Note that arm and aarch64 do not use cpu_breakpoint_test, but still
move the inline test down after tcg_gen_insn_start.

Backports commit b933066ae03d924a92b2616b4a24e7d91cd5b841 from qemu

qemu/include/qom/cpu.h

@@ -612,6 +612,7 @@ void cpu_single_step(CPUState *cpu, int enabled);
 /* 0x08 currently unused */
 #define BP_GDB                0x10
 #define BP_CPU                0x20
+#define BP_ANY                (BP_GDB | BP_CPU)
 #define BP_WATCHPOINT_HIT_READ 0x40
 #define BP_WATCHPOINT_HIT_WRITE 0x80
 #define BP_WATCHPOINT_HIT (BP_WATCHPOINT_HIT_READ | BP_WATCHPOINT_HIT_WRITE)
@@ -629,6 +630,21 @@ int cpu_watchpoint_remove(CPUState *cpu, vaddr addr,
 void cpu_watchpoint_remove_by_ref(CPUState *cpu, CPUWatchpoint *watchpoint);
 void cpu_watchpoint_remove_all(CPUState *cpu, int mask);
 
+/* Return true if PC matches an installed breakpoint.  */
+static inline bool cpu_breakpoint_test(CPUState *cpu, vaddr pc, int mask)
+{
+    CPUBreakpoint *bp;
+
+    if (unlikely(!QTAILQ_EMPTY(&cpu->breakpoints))) {
+        QTAILQ_FOREACH(bp, &cpu->breakpoints, entry) {
+            if (bp->pc == pc && (bp->flags & mask)) {
+                return true;
+            }
+        }
+    }
+    return false;
+}
+
 void QEMU_NORETURN cpu_abort(CPUState *cpu, const char *fmt, ...)
     GCC_FMT_ATTR(2, 3);
 

qemu/target-arm/translate-a64.c

@@ -11216,7 +11216,6 @@ void gen_intermediate_code_a64(ARMCPU *cpu, TranslationBlock *tb)
     CPUState *cs = CPU(cpu);
     CPUARMState *env = &cpu->env;
     DisasContext dc1, *dc = &dc1;
-    CPUBreakpoint *bp;
     target_ulong pc_start;
     target_ulong next_page_start;
     int num_insns;
@@ -11316,28 +11315,22 @@ void gen_intermediate_code_a64(ARMCPU *cpu, TranslationBlock *tb)
     gen_tb_start(tcg_ctx);
 
     do {
+        tcg_gen_insn_start(tcg_ctx, dc->pc, 0);
+        num_insns++;
+
         if (unlikely(!QTAILQ_EMPTY(&cs->breakpoints))) {
+            CPUBreakpoint *bp;
             QTAILQ_FOREACH(bp, &cs->breakpoints, entry) {
                 if (bp->pc == dc->pc) {
-                    if (bp->flags & BP_CPU) {
-                        gen_helper_check_breakpoints(tcg_ctx, tcg_ctx->cpu_env);
-                        /* End the TB early; it likely won't be executed */
-                        dc->is_jmp = DISAS_UPDATE;
-                    } else {
-                        gen_exception_internal_insn(dc, 0, EXCP_DEBUG);
-                        /* Advance PC so that clearing the breakpoint will
-                           invalidate this TB.  */
-                        dc->pc += 4;
-                        goto done_generating;
-                    }
-                    break;
+                    gen_exception_internal_insn(dc, 0, EXCP_DEBUG);
+                    /* Advance PC so that clearing the breakpoint will
+                       invalidate this TB.  */
+                    dc->pc += 2;
+                    goto done_generating;
                 }
             }
         }
 
-        tcg_gen_insn_start(tcg_ctx, dc->pc, 0);
-        num_insns++;
-
         //if (num_insns == max_insns && (tb->cflags & CF_LAST_IO)) {
         //    gen_io_start();
         //}

qemu/target-arm/translate.c

@@ -11386,7 +11386,6 @@ void gen_intermediate_code(CPUARMState *env, TranslationBlock *tb)
     ARMCPU *cpu = arm_env_get_cpu(env);
     CPUState *cs = CPU(cpu);
     DisasContext dc1, *dc = &dc1;
-    CPUBreakpoint *bp;
     target_ulong pc_start;
     target_ulong next_page_start;
     int num_insns;
@@ -11541,7 +11540,9 @@ void gen_intermediate_code(CPUARMState *env, TranslationBlock *tb)
         store_cpu_field(tcg_ctx, tmp, condexec_bits);
       }
     do {
-        //printf(">>> arm pc = %x\n", dc->pc);
+        tcg_gen_insn_start(tcg_ctx, dc->pc,
+                           (dc->condexec_cond << 4) | (dc->condexec_mask >> 1));
+        num_insns++;
 #ifdef CONFIG_USER_ONLY
         /* Intercept jump to the magic kernel page.  */
         if (dc->pc >= 0xffff0000) {
@@ -11562,6 +11563,7 @@ void gen_intermediate_code(CPUARMState *env, TranslationBlock *tb)
 #endif
 
         if (unlikely(!QTAILQ_EMPTY(&cs->breakpoints))) {
+            CPUBreakpoint *bp;
             QTAILQ_FOREACH(bp, &cs->breakpoints, entry) {
                 if (bp->pc == dc->pc) {
                     if (bp->flags & BP_CPU) {
@@ -11582,10 +11584,6 @@ void gen_intermediate_code(CPUARMState *env, TranslationBlock *tb)
             }
         }
 
-        tcg_gen_insn_start(tcg_ctx, dc->pc,
-                           (dc->condexec_cond << 4) | (dc->condexec_mask >> 1));
-        num_insns++;
-
         //if (num_insns == max_insns && (tb->cflags & CF_LAST_IO)) {
         //    gen_io_start();
         //}

qemu/target-i386/translate.c

@@ -8567,7 +8567,6 @@ void gen_intermediate_code(CPUX86State *env, TranslationBlock *tb)
     TCGContext *tcg_ctx = env->uc->tcg_ctx;
     DisasContext dc1, *dc = &dc1;
     target_ulong pc_ptr;
-    CPUBreakpoint *bp;
     uint64_t flags;
     target_ulong pc_start;
     target_ulong cs_base;
@@ -8701,18 +8700,17 @@ void gen_intermediate_code(CPUX86State *env, TranslationBlock *tb)
 
     gen_tb_start(tcg_ctx);
     for(;;) {
-        if (unlikely(!QTAILQ_EMPTY(&cs->breakpoints))) {
-            QTAILQ_FOREACH(bp, &cs->breakpoints, entry) {
-                if (bp->pc == pc_ptr &&
-                    !((bp->flags & BP_CPU) && (tb->flags & HF_RF_MASK))) {
-                    gen_debug(dc, pc_ptr - dc->cs_base);
-                    goto done_generating;
-                }
-            }
-        }
         tcg_gen_insn_start(tcg_ctx, pc_start, dc->cc_op);
         num_insns++;
 
+        /* If RF is set, suppress an internally generated breakpoint.  */
+        if (unlikely(cpu_breakpoint_test(cs, pc_ptr,
+                                         tb->flags & HF_RF_MASK
+                                         ? BP_GDB : BP_ANY))) {
+            gen_debug(dc, pc_ptr - dc->cs_base);
+            goto done_generating;
+        }
+        // Unicorn: commented out
         //if (num_insns == max_insns && (tb->cflags & CF_LAST_IO)) {
         //    gen_io_start();
         //}

qemu/target-m68k/translate.c

@@ -3059,7 +3059,6 @@ void gen_intermediate_code(CPUM68KState *env, TranslationBlock *tb)
     M68kCPU *cpu = m68k_env_get_cpu(env);
     CPUState *cs = CPU(cpu);
     DisasContext dc1, *dc = &dc1;
-    CPUBreakpoint *bp;
     target_ulong pc_start;
     int pc_offset;
     int num_insns;
@@ -3112,20 +3111,15 @@ void gen_intermediate_code(CPUM68KState *env, TranslationBlock *tb)
     gen_tb_start(tcg_ctx);
     do {
         pc_offset = dc->pc - pc_start;
-        if (unlikely(!QTAILQ_EMPTY(&cs->breakpoints))) {
-            QTAILQ_FOREACH(bp, &cs->breakpoints, entry) {
-                if (bp->pc == dc->pc) {
-                    gen_exception(dc, dc->pc, EXCP_DEBUG);
-                    dc->is_jmp = DISAS_JUMP;
-                    break;
-                }
-            }
-            if (dc->is_jmp)
-                break;
-        }
         tcg_gen_insn_start(tcg_ctx, dc->pc);
         num_insns++;
 
+        if (unlikely(cpu_breakpoint_test(cs, dc->pc, BP_ANY))) {
+            gen_exception(dc, dc->pc, EXCP_DEBUG);
+            dc->is_jmp = DISAS_JUMP;
+            break;
+        }
+
         // UNICORN: Commented out
         //if (num_insns == max_insns && (tb->cflags & CF_LAST_IO)) {
         //    gen_io_start();

qemu/target-mips/translate.c

@@ -19701,7 +19701,6 @@ void gen_intermediate_code(CPUMIPSState *env, struct TranslationBlock *tb)
     DisasContext ctx;
     target_ulong pc_start;
     target_ulong next_page_start;
-    CPUBreakpoint *bp;
     int num_insns;
     int max_insns;
     int insn_bytes;
@@ -19773,24 +19772,19 @@ void gen_intermediate_code(CPUMIPSState *env, struct TranslationBlock *tb)
 
     gen_tb_start(tcg_ctx);
     while (ctx.bstate == BS_NONE) {
-        // printf(">>> mips pc = %x\n", ctx.pc);
-        if (unlikely(!QTAILQ_EMPTY(&cs->breakpoints))) {
-            QTAILQ_FOREACH(bp, &cs->breakpoints, entry) {
-                if (bp->pc == ctx.pc) {
-                    save_cpu_state(&ctx, 1);
-                    ctx.bstate = BS_BRANCH;
-                    gen_helper_raise_exception_debug(tcg_ctx, tcg_ctx->cpu_env);
-                    /* Include the breakpoint location or the tb won't
-                     * be flushed when it must be.  */
-                    ctx.pc += 4;
-                    goto done_generating;
-                }
-            }
-        }
-
         tcg_gen_insn_start(tcg_ctx, ctx.pc, ctx.hflags & MIPS_HFLAG_BMASK, ctx.btarget);
         num_insns++;
 
+        if (unlikely(cpu_breakpoint_test(cs, ctx.pc, BP_ANY))) {
+            save_cpu_state(&ctx, 1);
+            ctx.bstate = BS_BRANCH;
+            gen_helper_raise_exception_debug(tcg_ctx, tcg_ctx->cpu_env);
+            /* Include the breakpoint location or the tb won't
+             * be flushed when it must be.  */
+            ctx.pc += 4;
+            goto done_generating;
+        }
+
         // Unicorn: Commented out
         //if (num_insns == max_insns && (tb->cflags & CF_LAST_IO)) {
         //    gen_io_start();

qemu/target-sparc/translate.c

@@ -5363,7 +5363,6 @@ void gen_intermediate_code(CPUSPARCState * env, TranslationBlock * tb)
     CPUState *cs = CPU(cpu);
     target_ulong pc_start, last_pc;
     DisasContext dc1, *dc = &dc1;
-    CPUBreakpoint *bp;
     int num_insns = 0;
     int max_insns;
     unsigned int insn;
@@ -5419,18 +5418,6 @@ void gen_intermediate_code(CPUSPARCState * env, TranslationBlock * tb)
 
     gen_tb_start(tcg_ctx);
     do {
-        if (unlikely(!QTAILQ_EMPTY(&cs->breakpoints))) {
-            QTAILQ_FOREACH(bp, &cs->breakpoints, entry) {
-                if (bp->pc == dc->pc) {
-                    if (dc->pc != pc_start)
-                        save_state(dc);
-                    gen_helper_debug(tcg_ctx, tcg_ctx->cpu_env);
-                    tcg_gen_exit_tb(tcg_ctx, 0);
-                    dc->is_br = 1;
-                    goto exit_gen_loop;
-                }
-            }
-        }
         if (dc->npc & JUMP_PC) {
             assert(dc->jump_pc[1] == dc->pc + 4);
             tcg_gen_insn_start(tcg_ctx, dc->pc, dc->jump_pc[0] | JUMP_PC);
@@ -5439,6 +5426,16 @@ void gen_intermediate_code(CPUSPARCState * env, TranslationBlock * tb)
         }
         num_insns++;
 
+        if (unlikely(cpu_breakpoint_test(cs, dc->pc, BP_ANY))) {
+            if (dc->pc != pc_start) {
+                save_state(dc);
+            }
+            gen_helper_debug(tcg_ctx, tcg_ctx->cpu_env);
+            tcg_gen_exit_tb(tcg_ctx, 0);
+            dc->is_br = 1;
+            goto exit_gen_loop;
+        }
+
         //if (num_insns == max_insns && (tb->cflags & CF_LAST_IO)) {
         //    gen_io_start();
         //}