[Qemu-devel] [PATCH 19/22] tcg: introduce tcg_context_clone

[Emilio G. Cota]

Before we make TCGContext thread-local.

Signed-off-by: Emilio G. Cota <c...@braap.org>
---
 tcg/tcg.h |  1 +
 tcg/tcg.c | 14 ++++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/tcg/tcg.h b/tcg/tcg.h
index 2a64ee2..be5f3fd 100644
--- a/tcg/tcg.h
+++ b/tcg/tcg.h
@@ -778,6 +778,7 @@ static inline void *tcg_malloc(int size)
 }
 
 void tcg_context_init(TCGContext *s);
+void tcg_context_clone(TCGContext *s);
 void tcg_prologue_init(TCGContext *s);
 void tcg_register_thread(void);
 void tcg_func_start(TCGContext *s);
diff --git a/tcg/tcg.c b/tcg/tcg.c
index 2f003a0..8febf53 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -117,6 +117,7 @@ static bool tcg_out_tb_finalize(TCGContext *s);
 
 #define TCG_HIGHWATER 1024
 
+static const TCGContext *tcg_init_ctx;
 static QemuMutex tcg_lock;
 
 /*
@@ -353,6 +354,7 @@ void tcg_context_init(TCGContext *s)
     TCGArgConstraint *args_ct;
     int *sorted_args;
 
+    tcg_init_ctx = s;
     memset(s, 0, sizeof(*s));
     s->nb_globals = 0;
 
@@ -409,6 +411,18 @@ void tcg_context_init(TCGContext *s)
 }
 
 /*
+ * Clone the initial TCGContext. Used by TCG threads to copy the TCGContext
+ * set up by their parent thread via tcg_context_init().
+ */
+void tcg_context_clone(TCGContext *s)
+{
+    if (unlikely(tcg_init_ctx == NULL || tcg_init_ctx == s)) {
+        tcg_abort();
+    }
+    memcpy(s, tcg_init_ctx, sizeof(*s));
+}
+
+/*
  * Allocate TBs right before their corresponding translated code, making
  * sure that TBs and code are on different cache lines.
  */
-- 
2.7.4