diff mbox series

[1/3] virtio: add VM state change cb with return value

Message ID 20250309090708.3928953-2-haoqian.he@smartx.com (mailing list archive)
State New
Headers show
Series vhost: fix the IO error after live migration | expand

Commit Message

Haoqian He March 9, 2025, 9:07 a.m. UTC
This patch contains two changes:

1. Add VM state change cb type VMChangeStateHandlerExt which has return
value for virtio devices VMChangeStateEntry. When VM state changes,
virtio device will call the _Ext version.

2. Add return value for vm_state_notify().

Signed-off-by: Haoqian He <haoqian.he@smartx.com>
---
 hw/block/virtio-blk.c             |  2 +-
 hw/core/vm-change-state-handler.c | 14 ++++++++------
 hw/scsi/scsi-bus.c                |  2 +-
 hw/vfio/migration.c               |  2 +-
 hw/virtio/virtio.c                |  5 +++--
 include/system/runstate.h         | 11 ++++++++---
 system/cpus.c                     |  4 ++--
 system/runstate.c                 | 25 ++++++++++++++++++++-----
 8 files changed, 44 insertions(+), 21 deletions(-)
diff mbox series

Patch

diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index a1829e3abd..4d6c3c9a54 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -1918,7 +1918,7 @@  static void virtio_blk_device_realize(DeviceState *dev, Error **errp)
      * called after ->start_ioeventfd() has already set blk's AioContext.
      */
     s->change =
-        qdev_add_vm_change_state_handler(dev, virtio_blk_dma_restart_cb, s);
+        qdev_add_vm_change_state_handler(dev, virtio_blk_dma_restart_cb, NULL, s);
 
     blk_ram_registrar_init(&s->blk_ram_registrar, s->blk);
     blk_set_dev_ops(s->blk, &virtio_block_ops, s);
diff --git a/hw/core/vm-change-state-handler.c b/hw/core/vm-change-state-handler.c
index 7064995578..d5045b17c1 100644
--- a/hw/core/vm-change-state-handler.c
+++ b/hw/core/vm-change-state-handler.c
@@ -40,6 +40,7 @@  static int qdev_get_dev_tree_depth(DeviceState *dev)
  * qdev_add_vm_change_state_handler:
  * @dev: the device that owns this handler
  * @cb: the callback function to be invoked
+ * @cb_ext: the callback function with return value to be invoked
  * @opaque: user data passed to the callback function
  *
  * This function works like qemu_add_vm_change_state_handler() except callbacks
@@ -54,21 +55,22 @@  static int qdev_get_dev_tree_depth(DeviceState *dev)
  */
 VMChangeStateEntry *qdev_add_vm_change_state_handler(DeviceState *dev,
                                                      VMChangeStateHandler *cb,
+                                                     VMChangeStateHandlerExt *cb_ext,
                                                      void *opaque)
 {
-    return qdev_add_vm_change_state_handler_full(dev, cb, NULL, opaque);
+    return qdev_add_vm_change_state_handler_full(dev, cb, NULL, cb_ext, opaque);
 }
 
 /*
  * Exactly like qdev_add_vm_change_state_handler() but passes a prepare_cb
- * argument too.
+ * and the cb_ext arguments too.
  */
 VMChangeStateEntry *qdev_add_vm_change_state_handler_full(
-    DeviceState *dev, VMChangeStateHandler *cb,
-    VMChangeStateHandler *prepare_cb, void *opaque)
+    DeviceState *dev, VMChangeStateHandler *cb, VMChangeStateHandler *prepare_cb,
+    VMChangeStateHandlerExt *cb_ext, void *opaque)
 {
     int depth = qdev_get_dev_tree_depth(dev);
 
-    return qemu_add_vm_change_state_handler_prio_full(cb, prepare_cb, opaque,
-                                                      depth);
+    return qemu_add_vm_change_state_handler_prio_full(cb, prepare_cb, cb_ext,
+                                                      opaque, depth);
 }
diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c
index 7d4546800f..ec098f5f0a 100644
--- a/hw/scsi/scsi-bus.c
+++ b/hw/scsi/scsi-bus.c
@@ -356,7 +356,7 @@  static void scsi_qdev_realize(DeviceState *qdev, Error **errp)
         return;
     }
     dev->vmsentry = qdev_add_vm_change_state_handler(DEVICE(dev),
-            scsi_dma_restart_cb, dev);
+            scsi_dma_restart_cb, NULL, dev);
 }
 
 static void scsi_qdev_unrealize(DeviceState *qdev)
diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
index adfa752db5..52bb9a3845 100644
--- a/hw/vfio/migration.c
+++ b/hw/vfio/migration.c
@@ -976,7 +976,7 @@  static int vfio_migration_init(VFIODevice *vbasedev)
                      vfio_vmstate_change_prepare :
                      NULL;
     migration->vm_state = qdev_add_vm_change_state_handler_full(
-        vbasedev->dev, vfio_vmstate_change, prepare_cb, vbasedev);
+        vbasedev->dev, vfio_vmstate_change, prepare_cb, NULL, vbasedev);
     migration_add_notifier(&migration->migration_state,
                            vfio_migration_state_notifier);
 
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 85110bce37..5e8d4cab53 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -3419,7 +3419,7 @@  void virtio_cleanup(VirtIODevice *vdev)
     qemu_del_vm_change_state_handler(vdev->vmstate);
 }
 
-static void virtio_vmstate_change(void *opaque, bool running, RunState state)
+static int virtio_vmstate_change(void *opaque, bool running, RunState state)
 {
     VirtIODevice *vdev = opaque;
     BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
@@ -3438,6 +3438,7 @@  static void virtio_vmstate_change(void *opaque, bool running, RunState state)
     if (!backend_run) {
         virtio_set_status(vdev, vdev->status);
     }
+    return 0;
 }
 
 void virtio_instance_init_common(Object *proxy_obj, void *data,
@@ -3489,7 +3490,7 @@  void virtio_init(VirtIODevice *vdev, uint16_t device_id, size_t config_size)
         vdev->config = NULL;
     }
     vdev->vmstate = qdev_add_vm_change_state_handler(DEVICE(vdev),
-            virtio_vmstate_change, vdev);
+            NULL, virtio_vmstate_change, vdev);
     vdev->device_endian = virtio_default_endian();
     vdev->use_guest_notifier_mask = true;
 }
diff --git a/include/system/runstate.h b/include/system/runstate.h
index bffc3719d4..af33ea92b6 100644
--- a/include/system/runstate.h
+++ b/include/system/runstate.h
@@ -12,6 +12,7 @@  bool runstate_needs_reset(void);
 void runstate_replay_enable(void);
 
 typedef void VMChangeStateHandler(void *opaque, bool running, RunState state);
+typedef int VMChangeStateHandlerExt(void *opaque, bool running, RunState state);
 
 VMChangeStateEntry *qemu_add_vm_change_state_handler(VMChangeStateHandler *cb,
                                                      void *opaque);
@@ -20,21 +21,25 @@  VMChangeStateEntry *qemu_add_vm_change_state_handler_prio(
 VMChangeStateEntry *
 qemu_add_vm_change_state_handler_prio_full(VMChangeStateHandler *cb,
                                            VMChangeStateHandler *prepare_cb,
+                                           VMChangeStateHandlerExt *cb_ext,
                                            void *opaque, int priority);
 VMChangeStateEntry *qdev_add_vm_change_state_handler(DeviceState *dev,
                                                      VMChangeStateHandler *cb,
+                                                     VMChangeStateHandlerExt *cb_ext,
                                                      void *opaque);
 VMChangeStateEntry *qdev_add_vm_change_state_handler_full(
-    DeviceState *dev, VMChangeStateHandler *cb,
-    VMChangeStateHandler *prepare_cb, void *opaque);
+    DeviceState *dev, VMChangeStateHandler *cb, VMChangeStateHandler *prepare_cb,
+    VMChangeStateHandlerExt *cb_ext, void *opaque);
 void qemu_del_vm_change_state_handler(VMChangeStateEntry *e);
 /**
  * vm_state_notify: Notify the state of the VM
  *
  * @running: whether the VM is running or not.
  * @state: the #RunState of the VM.
+ *
+ * Return the result of the callback which has return value.
  */
-void vm_state_notify(bool running, RunState state);
+int vm_state_notify(bool running, RunState state);
 
 static inline bool shutdown_caused_by_guest(ShutdownCause cause)
 {
diff --git a/system/cpus.c b/system/cpus.c
index 37e5892c24..f07f72621e 100644
--- a/system/cpus.c
+++ b/system/cpus.c
@@ -298,14 +298,14 @@  static int do_vm_stop(RunState state, bool send_stop)
         if (oldstate == RUN_STATE_RUNNING) {
             pause_all_vcpus();
         }
-        vm_state_notify(0, state);
+        ret = vm_state_notify(0, state);
         if (send_stop) {
             qapi_event_send_stop();
         }
     }
 
     bdrv_drain_all();
-    ret = bdrv_flush_all();
+    ret |= bdrv_flush_all();
     trace_vm_stop_flush_all(ret);
 
     return ret;
diff --git a/system/runstate.c b/system/runstate.c
index 272801d307..2219cec409 100644
--- a/system/runstate.c
+++ b/system/runstate.c
@@ -297,6 +297,7 @@  void qemu_system_vmstop_request(RunState state)
 struct VMChangeStateEntry {
     VMChangeStateHandler *cb;
     VMChangeStateHandler *prepare_cb;
+    VMChangeStateHandlerExt *cb_ext;
     void *opaque;
     QTAILQ_ENTRY(VMChangeStateEntry) entries;
     int priority;
@@ -320,14 +321,15 @@  static QTAILQ_HEAD(, VMChangeStateEntry) vm_change_state_head =
 VMChangeStateEntry *qemu_add_vm_change_state_handler_prio(
         VMChangeStateHandler *cb, void *opaque, int priority)
 {
-    return qemu_add_vm_change_state_handler_prio_full(cb, NULL, opaque,
-                                                      priority);
+    return qemu_add_vm_change_state_handler_prio_full(cb, NULL, NULL,
+                                                      opaque, priority);
 }
 
 /**
  * qemu_add_vm_change_state_handler_prio_full:
  * @cb: the main callback to invoke
  * @prepare_cb: a callback to invoke before the main callback
+ * @cb_ext: the main callback to invoke with return value
  * @opaque: user data passed to the callbacks
  * @priority: low priorities execute first when the vm runs and the reverse is
  *            true when the vm stops
@@ -344,6 +346,7 @@  VMChangeStateEntry *qemu_add_vm_change_state_handler_prio(
 VMChangeStateEntry *
 qemu_add_vm_change_state_handler_prio_full(VMChangeStateHandler *cb,
                                            VMChangeStateHandler *prepare_cb,
+                                           VMChangeStateHandlerExt *cb_ext,
                                            void *opaque, int priority)
 {
     VMChangeStateEntry *e;
@@ -352,6 +355,7 @@  qemu_add_vm_change_state_handler_prio_full(VMChangeStateHandler *cb,
     e = g_malloc0(sizeof(*e));
     e->cb = cb;
     e->prepare_cb = prepare_cb;
+    e->cb_ext = cb_ext;
     e->opaque = opaque;
     e->priority = priority;
 
@@ -379,9 +383,10 @@  void qemu_del_vm_change_state_handler(VMChangeStateEntry *e)
     g_free(e);
 }
 
-void vm_state_notify(bool running, RunState state)
+int vm_state_notify(bool running, RunState state)
 {
     VMChangeStateEntry *e, *next;
+    int ret = 0;
 
     trace_vm_state_notify(running, state, RunState_str(state));
 
@@ -393,7 +398,12 @@  void vm_state_notify(bool running, RunState state)
         }
 
         QTAILQ_FOREACH_SAFE(e, &vm_change_state_head, entries, next) {
-            e->cb(e->opaque, running, state);
+            if (e->cb) {
+                e->cb(e->opaque, running, state);
+            } else if (e->cb_ext) {
+                // no need to process the result when starting VM
+                e->cb_ext(e->opaque, running, state);
+            }
         }
     } else {
         QTAILQ_FOREACH_REVERSE_SAFE(e, &vm_change_state_head, entries, next) {
@@ -403,9 +413,14 @@  void vm_state_notify(bool running, RunState state)
         }
 
         QTAILQ_FOREACH_REVERSE_SAFE(e, &vm_change_state_head, entries, next) {
-            e->cb(e->opaque, running, state);
+            if (e->cb) {
+                e->cb(e->opaque, running, state);
+            } else if (e->cb_ext) {
+                ret |= e->cb_ext(e->opaque, running, state);
+            }
         }
     }
+    return ret;
 }
 
 static ShutdownCause reset_requested;