target/sh4: Disable decode_gusa when plugins enabled

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230824181233.1568795-3-richard.henderson@linaro.org>
[AJB: fixed s/cpu_env/tcg_env/ during re-base]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20231009164104.369749-22-alex.bennee@linaro.org>

target/sh4/translate.c

@@ -1816,6 +1816,18 @@ static void decode_opc(DisasContext * ctx)
 }
 
 #ifdef CONFIG_USER_ONLY
+/*
+ * Restart with the EXCLUSIVE bit set, within a TB run via
+ * cpu_exec_step_atomic holding the exclusive lock.
+ */
+static void gen_restart_exclusive(DisasContext *ctx)
+{
+    ctx->envflags |= TB_FLAG_GUSA_EXCLUSIVE;
+    gen_save_cpu_state(ctx, false);
+    gen_helper_exclusive(tcg_env);
+    ctx->base.is_jmp = DISAS_NORETURN;
+}
+
 /* For uniprocessors, SH4 uses optimistic restartable atomic sequences.
    Upon an interrupt, a real kernel would simply notice magic values in
    the registers and reset the PC to the start of the sequence.
@@ -2149,12 +2161,7 @@ static void decode_gusa(DisasContext *ctx, CPUSH4State *env)
     qemu_log_mask(LOG_UNIMP, "Unrecognized gUSA sequence %08x-%08x\n",
                   pc, pc_end);
 
-    /* Restart with the EXCLUSIVE bit set, within a TB run via
-       cpu_exec_step_atomic holding the exclusive lock.  */
-    ctx->envflags |= TB_FLAG_GUSA_EXCLUSIVE;
-    gen_save_cpu_state(ctx, false);
-    gen_helper_exclusive(tcg_env);
-    ctx->base.is_jmp = DISAS_NORETURN;
+    gen_restart_exclusive(ctx);
 
     /* We're not executing an instruction, but we must report one for the
        purposes of accounting within the TB.  We might as well report the
@@ -2242,12 +2249,22 @@ static void sh4_tr_translate_insn(DisasContextBase *dcbase, CPUState *cs)
 #ifdef CONFIG_USER_ONLY
     if (unlikely(ctx->envflags & TB_FLAG_GUSA_MASK)
         && !(ctx->envflags & TB_FLAG_GUSA_EXCLUSIVE)) {
-        /* We're in an gUSA region, and we have not already fallen
-           back on using an exclusive region.  Attempt to parse the
-           region into a single supported atomic operation.  Failure
-           is handled within the parser by raising an exception to
-           retry using an exclusive region.  */
-        decode_gusa(ctx, env);
+        /*
+         * We're in an gUSA region, and we have not already fallen
+         * back on using an exclusive region.  Attempt to parse the
+         * region into a single supported atomic operation.  Failure
+         * is handled within the parser by raising an exception to
+         * retry using an exclusive region.
+         *
+         * Parsing the region in one block conflicts with plugins,
+         * so always use exclusive mode if plugins enabled.
+         */
+        if (ctx->base.plugin_enabled) {
+            gen_restart_exclusive(ctx);
+            ctx->base.pc_next += 2;
+        } else {
+            decode_gusa(ctx, env);
+        }
         return;
     }
 #endif