[V4,08/25] vl: add helper to request re-exec

Commit Message

Steven Sistare July 6, 2021, 4:45 p.m. UTC

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 <[e-mail]>
---
 include/sysemu/runstate.h |  1 +
 softmmu/runstate.c        | 37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)

Patch

diff --git a/include/sysemu/runstate.h b/include/sysemu/runstate.h
index ed4b735..e1ae7e5 100644
--- a/include/sysemu/runstate.h
+++ b/include/sysemu/runstate.h
@@ -57,6 +57,7 @@  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);
+void qemu_system_exec_request(strList *args);
 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 ccb35cb..554dfc6 100644
--- a/softmmu/runstate.c
+++ b/softmmu/runstate.c
@@ -354,6 +354,7 @@  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 char **exec_argv;
 
 ShutdownCause qemu_shutdown_requested_get(void)
 {
@@ -370,6 +371,11 @@  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) {
@@ -644,6 +650,32 @@  void qemu_system_shutdown_request(ShutdownCause reason)
     qemu_notify_event();
 }
 
+static char **make_argv(strList *args)
+{
+    strList *arg;
+    char **argv;
+    int n = 1, i = 0;
+
+    for (arg = args; arg != NULL; arg = arg->next) {
+        n++;
+    }
+
+    argv = g_malloc(n * sizeof(char *));
+    for (arg = args; arg != NULL; arg = arg->next) {
+        argv[i++] = g_strdup(arg->value);
+    }
+    argv[i] = NULL;
+
+    return argv;
+}
+
+void qemu_system_exec_request(strList *args)
+{
+    exec_argv = make_argv(args);
+    shutdown_requested = 1;
+    qemu_notify_event();
+}
+
 static void qemu_system_powerdown(void)
 {
     qapi_event_send_powerdown();
@@ -692,6 +724,11 @@  static bool main_loop_should_exit(void)
     }
     request = qemu_shutdown_requested();
     if (request) {
+
+        if (qemu_exec_requested()) {
+            execvp(exec_argv[0], exec_argv);
+            error_setg_errno(&error_fatal, errno, "execvp failed");
+        }
         qemu_kill_report();
         qemu_system_shutdown(request);
         if (shutdown_action == SHUTDOWN_ACTION_PAUSE) {