[Qemu-devel] [RFC PATCH v4 13/13] cexe: allow to enable reverse execution.

[fred.konrad@greensocs.com]

From: KONRAD Frederic <fred.konrad@greensocs.com>

This creates QEMU options for reverse execution.

Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
---
 qemu-options.hx |  9 +++++++++
 vl.c            | 16 ++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/qemu-options.hx b/qemu-options.hx
index ff76ad4..2afb85d 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2946,6 +2946,15 @@ order cores with complex cache hierarchies.  The number of instructions
 executed often has little or no correlation with actual performance.
 ETEXI
 
+DEF("cexe", 0, QEMU_OPTION_cexe, \
+    "-cexe\n" \
+    "                enable reverse execution\n", QEMU_ARCH_ALL)
+STEXI
+@item -cexe
+@findex -cexe
+Enable reverse execution.
+ETEXI
+
 DEF("watchdog", HAS_ARG, QEMU_OPTION_watchdog, \
     "-watchdog i6300esb|ib700\n" \
     "                enable virtual hardware watchdog [default=none]\n",
diff --git a/vl.c b/vl.c
index d0352e3..a94563a 100644
--- a/vl.c
+++ b/vl.c
@@ -228,6 +228,7 @@ static int default_floppy = 1;
 static int default_cdrom = 1;
 static int default_sdcard = 1;
 static int default_vga = 1;
+static int default_cexe;
 
 static struct {
     const char *driver;
@@ -3821,6 +3822,9 @@ int main(int argc, char **argv, char **envp)
             case QEMU_OPTION_icount:
                 icount_option = optarg;
                 break;
+            case QEMU_OPTION_cexe:
+                default_cexe = true;
+                break;
             case QEMU_OPTION_incoming:
                 incoming = optarg;
                 runstate_set(RUN_STATE_INMIGRATE);
@@ -4520,6 +4524,15 @@ int main(int argc, char **argv, char **envp)
         vm_start();
     }
 
+    if (default_cexe) {
+        if (!icount_option) {
+            fprintf(stderr, "Reverse execution requires icount.\n");
+            exit(1);
+        }
+
+        cexe_setup();
+    }
+
     os_setup_post();
 
     if (is_daemonized()) {
@@ -4536,5 +4549,8 @@ int main(int argc, char **argv, char **envp)
     tpm_cleanup();
 #endif
 
+    if (cexe_is_enabled()) {
+        cexe_cleanup();
+    }
     return 0;
 }
-- 
1.9.0