[Qemu-devel] [PATCH v6 1/2] move vm_start to cpus.c

[Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>]

This patch:

* moves vm_start to cpus.c .
* exports qemu_vmstop_requested, since it's needed by vm_start .
* extracts vm_prepare_start from vm_start; it does what vm_start did,
  except restarting the cpus. vm_start now calls vm_prepare_start.
* moves the call to qemu_clock_enable away from resume_all_vcpus, and
  add an explicit call to it before each instance of resume_all_vcpus
  in the code.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
---
 cpus.c                  | 42 ++++++++++++++++++++++++++++++++++++++++++
 include/sysemu/sysemu.h |  2 ++
 vl.c                    | 30 +-----------------------------
 3 files changed, 45 insertions(+), 29 deletions(-)

diff --git a/cpus.c b/cpus.c
index 71a82e5..061de39 100644
--- a/cpus.c
+++ b/cpus.c
@@ -1578,6 +1578,48 @@ int vm_stop(RunState state)
     return do_vm_stop(state);
 }
 
+/**
+ * Prepare for (re)starting the VM.
+ * Returns -1 if the vCPUs are not to be restarted (e.g. if they are already
+ * running or in case of an error condition), 0 otherwise.
+ */
+int vm_prepare_start(void)
+{
+    RunState requested;
+    int res = 0;
+
+    qemu_vmstop_requested(&requested);
+    if (runstate_is_running() && requested == RUN_STATE__MAX) {
+        return -1;
+    }
+
+    /* Ensure that a STOP/RESUME pair of events is emitted if a
+     * vmstop request was pending.  The BLOCK_IO_ERROR event, for
+     * example, according to documentation is always followed by
+     * the STOP event.
+     */
+    if (runstate_is_running()) {
+        qapi_event_send_stop(&error_abort);
+        res = -1;
+    } else {
+        replay_enable_events();
+        cpu_enable_ticks();
+        runstate_set(RUN_STATE_RUNNING);
+        vm_state_notify(1, RUN_STATE_RUNNING);
+    }
+
+    /* XXX: is it ok to send this even before actually resuming the CPUs? */
+    qapi_event_send_resume(&error_abort);
+    return res;
+}
+
+void vm_start(void)
+{
+    if (!vm_prepare_start()) {
+        resume_all_vcpus();
+    }
+}
+
 /* does a state transition even if the VM is already stopped,
    current state is forgotten forever */
 int vm_stop_force_state(RunState state)
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index ff8ffb5..0bb0c40 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -37,6 +37,7 @@ void vm_state_notify(int running, RunState state);
 #define VMRESET_REPORT   true
 
 void vm_start(void);
+int vm_prepare_start(void);
 int vm_stop(RunState state);
 int vm_stop_force_state(RunState state);
 
@@ -60,6 +61,7 @@ void qemu_register_powerdown_notifier(Notifier *notifier);
 void qemu_system_debug_request(void);
 void qemu_system_vmstop_request(RunState reason);
 void qemu_system_vmstop_request_prepare(void);
+bool qemu_vmstop_requested(RunState *r);
 int qemu_shutdown_requested_get(void);
 int qemu_reset_requested_get(void);
 void qemu_system_killed(int signal, pid_t pid);
diff --git a/vl.c b/vl.c
index abb0900..7a32a30 100644
--- a/vl.c
+++ b/vl.c
@@ -757,7 +757,7 @@ StatusInfo *qmp_query_status(Error **errp)
     return info;
 }
 
-static bool qemu_vmstop_requested(RunState *r)
+bool qemu_vmstop_requested(RunState *r)
 {
     qemu_mutex_lock(&vmstop_lock);
     *r = vmstop_requested;
@@ -778,34 +778,6 @@ void qemu_system_vmstop_request(RunState state)
     qemu_notify_event();
 }
 
-void vm_start(void)
-{
-    RunState requested;
-
-    qemu_vmstop_requested(&requested);
-    if (runstate_is_running() && requested == RUN_STATE__MAX) {
-        return;
-    }
-
-    /* Ensure that a STOP/RESUME pair of events is emitted if a
-     * vmstop request was pending.  The BLOCK_IO_ERROR event, for
-     * example, according to documentation is always followed by
-     * the STOP event.
-     */
-    if (runstate_is_running()) {
-        qapi_event_send_stop(&error_abort);
-    } else {
-        replay_enable_events();
-        cpu_enable_ticks();
-        runstate_set(RUN_STATE_RUNNING);
-        vm_state_notify(1, RUN_STATE_RUNNING);
-        resume_all_vcpus();
-    }
-
-    qapi_event_send_resume(&error_abort);
-}
-
-
 /***********************************************************/
 /* real time host monotonic timer */
 
-- 
1.9.1