translate-all: add DEBUG_LOCKING asserts

This adds asserts to check the locking on the various translation engines structures. There are two sets of structures that are protected by locks. The first the l1map and PageDesc structures used to track which translation blocks are associated with which physical addresses. In user-mode this is covered by the mmap_lock. The second case are TB context related structures which are protected by tb_lock which is also user-mode only. Currently the asserts do nothing in SoftMMU mode but this will change for MTTCG. Signed-off-by: Alex Bennée <[email protected]> Reviewed-by: Richard Henderson <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
NarutoGit · Oct 31, 2016 · 301e40e · 301e40e
1 parent 955939a
commit 301e40e
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Showing 4 changed files with 52 additions and 0 deletions.
diff --git a/bsd-user/mmap.c b/bsd-user/mmap.c
@@ -42,6 +42,11 @@ void mmap_unlock(void)
     }
 }
 
+bool have_mmap_lock(void)
+{
+    return mmap_lock_count > 0 ? true : false;
+}
+
 /* Grab lock to make sure things are in a consistent state after fork().  */
 void mmap_fork_start(void)
 {

diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
@@ -369,6 +369,7 @@ void tlb_fill(CPUState *cpu, target_ulong addr, MMUAccessType access_type,
 #if defined(CONFIG_USER_ONLY)
 void mmap_lock(void);
 void mmap_unlock(void);
+bool have_mmap_lock(void);
 
 static inline tb_page_addr_t get_page_addr_code(CPUArchState *env1, target_ulong addr)
 {

diff --git a/linux-user/mmap.c b/linux-user/mmap.c
@@ -41,6 +41,11 @@ void mmap_unlock(void)
     }
 }
 
+bool have_mmap_lock(void)
+{
+    return mmap_lock_count > 0 ? true : false;
+}
+
 /* Grab lock to make sure things are in a consistent state after fork().  */
 void mmap_fork_start(void)
 {

diff --git a/translate-all.c b/translate-all.c
@@ -31,6 +31,7 @@
 #include "tcg.h"
 #if defined(CONFIG_USER_ONLY)
 #include "qemu.h"
+#include "exec/exec-all.h"
 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
 #include <sys/param.h>
 #if __FreeBSD_version >= 700104
@@ -58,6 +59,7 @@
 
 /* #define DEBUG_TB_INVALIDATE */
 /* #define DEBUG_TB_FLUSH */
+/* #define DEBUG_LOCKING */
 /* make various TB consistency checks */
 /* #define DEBUG_TB_CHECK */
 
@@ -66,6 +68,28 @@
 #undef DEBUG_TB_CHECK
 #endif
 
+/* Access to the various translations structures need to be serialised via locks
+ * for consistency. This is automatic for SoftMMU based system
+ * emulation due to its single threaded nature. In user-mode emulation
+ * access to the memory related structures are protected with the
+ * mmap_lock.
+ */
+#ifdef DEBUG_LOCKING
+#define DEBUG_MEM_LOCKS 1
+#else
+#define DEBUG_MEM_LOCKS 0
+#endif
+
+#ifdef CONFIG_SOFTMMU
+#define assert_memory_lock() do { /* nothing */ } while (0)
+#else
+#define assert_memory_lock() do {               \
+        if (DEBUG_MEM_LOCKS) {                  \
+            g_assert(have_mmap_lock());         \
+        }                                       \
+    } while (0)
+#endif
+
 #define SMC_BITMAP_USE_THRESHOLD 10
 
 typedef struct PageDesc {
@@ -173,6 +197,23 @@ void tb_lock_reset(void)
 #endif
 }
 
+#ifdef DEBUG_LOCKING
+#define DEBUG_TB_LOCKS 1
+#else
+#define DEBUG_TB_LOCKS 0
+#endif
+
+#ifdef CONFIG_SOFTMMU
+#define assert_tb_lock() do { /* nothing */ } while (0)
+#else
+#define assert_tb_lock() do {               \
+        if (DEBUG_TB_LOCKS) {               \
+            g_assert(have_tb_lock);         \
+        }                                   \
+    } while (0)
+#endif
+
+
 static TranslationBlock *tb_find_pc(uintptr_t tc_ptr);
 
 void cpu_gen_init(void)