accel/tcg: Add CF_NO_GOTO_TB and CF_NO_GOTO_PTR

Move the -d nochain check to bits on tb->cflags.
These will be used for more than -d nochain shortly.

Set bits during curr_cflags, test them in translator_use_goto_tb,
assert we're not doing anything odd in tcg_gen_goto_tb.  The test
in tcg_gen_exit_tb is redundant with the assert for goto_tb_issue_mask.

Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20210717221851.2124573-4-richard.henderson@linaro.org>

accel/tcg/cpu-exec.c

@@ -147,7 +147,13 @@ static void init_delay_params(SyncClocks *sc, const CPUState *cpu)
 
 uint32_t curr_cflags(CPUState *cpu)
 {
-    return cpu->tcg_cflags;
+    uint32_t cflags = cpu->tcg_cflags;
+
+    if (qemu_loglevel_mask(CPU_LOG_TB_NOCHAIN)) {
+        cflags |= CF_NO_GOTO_TB | CF_NO_GOTO_PTR;
+    }
+
+    return cflags;
 }
 
 /* Might cause an exception, so have a longjmp destination ready */

accel/tcg/translator.c

@@ -33,6 +33,11 @@ void translator_loop_temp_check(DisasContextBase *db)
 
 bool translator_use_goto_tb(DisasContextBase *db, target_ulong dest)
 {
+    /* Suppress goto_tb if requested. */
+    if (tb_cflags(db->tb) & CF_NO_GOTO_TB) {
+        return false;
+    }
+
     /* Suppress goto_tb in the case of single-steping.  */
     if (db->singlestep_enabled || singlestep) {
         return false;