From b48508a6c1bee8b5ccd5226cfc9a69f32fbf3efe Mon Sep 17 00:00:00 2001
From: Richard Henderson <rth@twiddle.net>
Date: Tue, 27 Feb 2018 22:27:49 -0500
Subject: [PATCH] tcg: Emit barriers with parallel_cpus

Backports commit 91682118aa330aff7e8ef0cc685c32d101f49940 from qemu
---
 qemu/tcg/tcg-op.c | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/qemu/tcg/tcg-op.c b/qemu/tcg/tcg-op.c
index fe083ef0..374a485e 100644
--- a/qemu/tcg/tcg-op.c
+++ b/qemu/tcg/tcg-op.c
@@ -149,17 +149,7 @@ void tcg_gen_op6(TCGContext *ctx, TCGOpcode opc, TCGArg a1, TCGArg a2,
 
 void tcg_gen_mb(TCGContext *ctx, TCGBar mb_type)
 {
-    bool emit_barriers = true;
-
-#ifndef CONFIG_USER_ONLY
-    /* TODO: When MTTCG is available for system mode, we will check
-     * the following condition and enable emit_barriers
-     * (qemu_tcg_mttcg_enabled() && smp_cpus > 1)
-     */
-    emit_barriers = false;
-#endif
-
-    if (emit_barriers) {
+    if (ctx->uc->parallel_cpus) {
         tcg_gen_op1(ctx, INDEX_op_mb, mb_type);
     }
 }