[Qemu-devel] [PATCH v8 10/25] tcg: enable tb_lock() for SoftMMU

[Alex Bennée]

tb_lock() has long been used for linux-user mode to protect code
generation. By enabling it now we prepare for MTTCG and ensure all code
generation is serialised by this lock. The other major structure that
needs protecting is the l1_map and its PageDesc structures. For the
SoftMMU case we also use tb_lock() to protect these structures instead
of linux-user mmap_lock() which as the name suggests serialises updates
to the structure as a result of guest mmap operations.

Signed-off-by: Alex Bennée <address@hidden>
Reviewed-by: Richard Henderson <address@hidden>
---
v4
  - split from main tcg: enable thread-per-vCPU patch
v7
  - fixed up with Pranith's tcg_debug_assert() changes
---
 translate-all.c | 15 +--------------
 1 file changed, 1 insertion(+), 14 deletions(-)

diff --git a/translate-all.c b/translate-all.c
index 41b36f04c6..87e9d00d14 100644
--- a/translate-all.c
+++ b/translate-all.c
@@ -75,7 +75,7 @@
  * mmap_lock.
  */
 #ifdef CONFIG_SOFTMMU
-#define assert_memory_lock() do { /* nothing */ } while (0)
+#define assert_memory_lock() tcg_debug_assert(have_tb_lock)
 #else
 #define assert_memory_lock() tcg_debug_assert(have_mmap_lock())
 #endif
@@ -135,9 +135,7 @@ TCGContext tcg_ctx;
 bool parallel_cpus;
 
 /* translation block context */
-#ifdef CONFIG_USER_ONLY
 __thread int have_tb_lock;
-#endif
 
 static void page_table_config_init(void)
 {
@@ -159,40 +157,29 @@ static void page_table_config_init(void)
     assert(v_l2_levels >= 0);
 }
 
-#ifdef CONFIG_USER_ONLY
 #define assert_tb_locked() tcg_debug_assert(have_tb_lock)
 #define assert_tb_unlocked() tcg_debug_assert(!have_tb_lock)
-#else
-#define assert_tb_locked()  do { /* nothing */ } while (0)
-#define assert_tb_unlocked()  do { /* nothing */ } while (0)
-#endif
 
 void tb_lock(void)
 {
-#ifdef CONFIG_USER_ONLY
     assert_tb_unlocked();
     qemu_mutex_lock(&tcg_ctx.tb_ctx.tb_lock);
     have_tb_lock++;
-#endif
 }
 
 void tb_unlock(void)
 {
-#ifdef CONFIG_USER_ONLY
     assert_tb_locked();
     have_tb_lock--;
     qemu_mutex_unlock(&tcg_ctx.tb_ctx.tb_lock);
-#endif
 }
 
 void tb_lock_reset(void)
 {
-#ifdef CONFIG_USER_ONLY
     if (have_tb_lock) {
         qemu_mutex_unlock(&tcg_ctx.tb_ctx.tb_lock);
         have_tb_lock = 0;
     }
-#endif
 }
 
 static TranslationBlock *tb_find_pc(uintptr_t tc_ptr);
-- 
2.11.0