The current exec and cpu flags only show information when we enter a
TranslationBlock. The blocks will then chain together until there is a
reason to exit which can make things harder to follow. This new option
disables the chaining for debugging purposes.
Signed-off-by: Alex Bennée <alex.ben...@linaro.org>
diff --git a/cpu-exec.c b/cpu-exec.c
index abe02b7..c20349c 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -620,8 +620,10 @@ int cpu_exec(CPUArchState *env)
}
/* see if we can patch the calling TB. When the TB
spans two pages, we cannot safely do a direct
- jump. */
- if (next_tb != 0 && tb->page_addr[1] == -1) {
+ jump. It can also complicate tracing so disable if
+ asked (but be aware this can change behaviour). */
+ if (next_tb != 0 && tb->page_addr[1] == -1 &&
+ !qemu_loglevel_mask (CPU_LOG_TB_NOCHAIN)) {
tb_add_jump((TranslationBlock *)(next_tb & ~TB_EXIT_MASK),
next_tb & TB_EXIT_MASK, tb);
}
diff --git a/include/qemu/log.h b/include/qemu/log.h
index f6cef9e..82902b0 100644
--- a/include/qemu/log.h
+++ b/include/qemu/log.h
@@ -40,6 +40,7 @@ static inline bool qemu_log_enabled(void)
#define CPU_LOG_RESET (1 << 9)
#define LOG_UNIMP (1 << 10)
#define LOG_GUEST_ERROR (1 << 11)
+#define CPU_LOG_TB_NOCHAIN (1 << 12)
/* Returns true if a bit is set in the current loglevel mask
*/
diff --git a/qemu-log.c b/qemu-log.c
index a54b332..dc78a93 100644
--- a/qemu-log.c
+++ b/qemu-log.c
@@ -175,6 +175,8 @@ const QEMULogItem qemu_log_items[] = {
{ LOG_GUEST_ERROR, "guest_errors",
"log when the guest OS does something invalid (eg accessing a\n"
"non-existent register)" },
+ { CPU_LOG_TB_NOCHAIN, "nochain",
+ "disable chaining of translation blocks (better tracing, but slower)" },
{ 0, NULL, NULL },
};
--
1.9.1
