trace: add some tcg tracing support
This adds a couple of tcg specific trace-events which are useful for
tracing execution though tcg generated blocks. It's been tested with
lttng user space tracing but is generic enough for all systems. The tcg
events are:
* translate_block - when a subject block is translated
* exec_tb - when a translated block is entered
* exec_tb_exit - when we exit the translated code
* exec_tb_nocache - special case translations
Of course we can only trace the entrance to the first block of a chain
as each block will jump directly to the next when it can. See the -d
nochain patch to allow more complete tracing at the expense of
performance.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/cpu-exec.c b/cpu-exec.c
index cbc8067..c6aad74 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -18,6 +18,7 @@
*/
#include "config.h"
#include "cpu.h"
+#include "trace.h"
#include "disas/disas.h"
#include "tcg.h"
#include "qemu/atomic.h"
@@ -168,6 +169,9 @@
#endif /* DEBUG_DISAS */
next_tb = tcg_qemu_tb_exec(env, tb_ptr);
+ trace_exec_tb_exit((void *) (next_tb & ~TB_EXIT_MASK),
+ next_tb & TB_EXIT_MASK);
+
if ((next_tb & TB_EXIT_MASK) > TB_EXIT_IDX1) {
/* We didn't start executing this TB (eg because the instruction
* counter hit zero); we must restore the guest PC to the address
@@ -208,6 +212,7 @@
max_cycles);
cpu->current_tb = tb;
/* execute the generated code */
+ trace_exec_tb_nocache(tb, tb->pc);
cpu_tb_exec(cpu, tb->tc_ptr);
cpu->current_tb = NULL;
tb_phys_invalidate(tb, -1);
@@ -749,6 +754,7 @@
cpu->current_tb = tb;
barrier();
if (likely(!cpu->exit_request)) {
+ trace_exec_tb(tb, tb->pc);
tc_ptr = tb->tc_ptr;
/* execute the generated code */
next_tb = cpu_tb_exec(cpu, tc_ptr);
