[PATCH V8 18/39] vl: helper to request re-exec

[Steve Sistare]

Add a qemu_system_exec_request() hook that causes the main loop to exit and
re-exec qemu using the specified arguments.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
---
 include/sysemu/runstate.h |  1 +
 softmmu/runstate.c        | 26 ++++++++++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/include/sysemu/runstate.h b/include/sysemu/runstate.h
index 16c1c41..6b0b4f1 100644
--- a/include/sysemu/runstate.h
+++ b/include/sysemu/runstate.h
@@ -63,6 +63,7 @@ void qemu_system_wakeup_enable(WakeupReason reason, bool 
enabled);
 void qemu_register_wakeup_notifier(Notifier *notifier);
 void qemu_register_wakeup_support(void);
 void qemu_system_shutdown_request(ShutdownCause reason);
+int qemu_system_exec_request(const strList *args, Error **errp);
 void qemu_system_powerdown_request(void);
 void qemu_register_powerdown_notifier(Notifier *notifier);
 void qemu_register_shutdown_notifier(Notifier *notifier);
diff --git a/softmmu/runstate.c b/softmmu/runstate.c
index cfd6aa9..c35ab09 100644
--- a/softmmu/runstate.c
+++ b/softmmu/runstate.c
@@ -37,6 +37,7 @@
 #include "monitor/monitor.h"
 #include "net/net.h"
 #include "net/vhost_net.h"
+#include "qapi/util.h"
 #include "qapi/error.h"
 #include "qapi/qapi-commands-run-state.h"
 #include "qapi/qapi-events-run-state.h"
@@ -355,6 +356,7 @@ static NotifierList wakeup_notifiers =
 static NotifierList shutdown_notifiers =
     NOTIFIER_LIST_INITIALIZER(shutdown_notifiers);
 static uint32_t wakeup_reason_mask = ~(1 << QEMU_WAKEUP_REASON_NONE);
+static GStrv exec_argv;
 
 ShutdownCause qemu_shutdown_requested_get(void)
 {
@@ -371,6 +373,11 @@ static int qemu_shutdown_requested(void)
     return qatomic_xchg(&shutdown_requested, SHUTDOWN_CAUSE_NONE);
 }
 
+static int qemu_exec_requested(void)
+{
+    return exec_argv != NULL;
+}
+
 static void qemu_kill_report(void)
 {
     if (!qtest_driver() && shutdown_signal) {
@@ -641,6 +648,18 @@ void qemu_system_shutdown_request(ShutdownCause reason)
     qemu_notify_event();
 }
 
+int qemu_system_exec_request(const strList *args, Error **errp)
+{
+    exec_argv = strv_from_strList(args);
+    if (!exec_argv[0]) {
+        error_setg(errp, "qemu_system_exec_request: argv[0] is NULL");
+        return 1;
+    }
+    shutdown_requested = 1;
+    qemu_notify_event();
+    return 0;
+}
+
 static void qemu_system_powerdown(void)
 {
     qapi_event_send_powerdown();
@@ -689,6 +708,13 @@ static bool main_loop_should_exit(void)
     }
     request = qemu_shutdown_requested();
     if (request) {
+
+        if (qemu_exec_requested()) {
+            execvp(exec_argv[0], exec_argv);
+            error_report("execvp %s failed: %s", exec_argv[0], 
strerror(errno));
+            g_strfreev(exec_argv);
+            exec_argv = NULL;
+        }
         qemu_kill_report();
         qemu_system_shutdown(request);
         if (shutdown_action == SHUTDOWN_ACTION_PAUSE) {
-- 
1.8.3.1