[Qemu-devel] [PATCH 2/5] disk_deadlines: add request to resume Virtual Machine

["Denis V. Lunev" <den@openvz.org>]

From: Raushaniya Maksudova <rmaksudova@virtuozzo.com>

In some cases one needs to pause and resume a Virtual Machine from inside
of Qemu. Currently there are request functions to pause VM (vmstop), but
there are no respective ones to resume VM.

Signed-off-by: Raushaniya Maksudova <rmaksudova@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
---
 include/sysemu/sysemu.h |  1 +
 stubs/vm-stop.c         |  5 +++++
 vl.c                    | 18 ++++++++++++++++++
 3 files changed, 24 insertions(+)

diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 44570d1..a382ae1 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -62,6 +62,7 @@ void qemu_system_shutdown_request(void);
 void qemu_system_powerdown_request(void);
 void qemu_register_powerdown_notifier(Notifier *notifier);
 void qemu_system_debug_request(void);
+void qemu_system_vmstart_request(void);
 void qemu_system_vmstop_request(RunState reason);
 void qemu_system_vmstop_request_prepare(void);
 int qemu_shutdown_requested_get(void);
diff --git a/stubs/vm-stop.c b/stubs/vm-stop.c
index 69fd86b..c8e2cdd 100644
--- a/stubs/vm-stop.c
+++ b/stubs/vm-stop.c
@@ -10,3 +10,8 @@ void qemu_system_vmstop_request(RunState state)
 {
     abort();
 }
+
+void qemu_system_vmstart_request(void)
+{
+    abort();
+}
diff --git a/vl.c b/vl.c
index 584ca88..63f10d3 100644
--- a/vl.c
+++ b/vl.c
@@ -563,6 +563,7 @@ static RunState current_run_state = RUN_STATE_PRELAUNCH;
 /* We use RUN_STATE_MAX but any invalid value will do */
 static RunState vmstop_requested = RUN_STATE_MAX;
 static QemuMutex vmstop_lock;
+static bool vmstart_requested;
 
 typedef struct {
     RunState from;
@@ -723,6 +724,19 @@ void qemu_system_vmstop_request(RunState state)
     qemu_notify_event();
 }
 
+static bool qemu_vmstart_requested(void)
+{
+    bool r = vmstart_requested;
+    vmstart_requested = false;
+    return r;
+}
+
+void qemu_system_vmstart_request(void)
+{
+    vmstart_requested = true;
+    qemu_notify_event();
+}
+
 void vm_start(void)
 {
     RunState requested;
@@ -1884,6 +1898,10 @@ static bool main_loop_should_exit(void)
     if (qemu_vmstop_requested(&r)) {
         vm_stop(r);
     }
+    if (qemu_vmstart_requested()) {
+        vm_start();
+    }
+
     return false;
 }
 
-- 
2.1.4