From 032fc7e1bc37a62ea45d77be9e96847a58bb25c9 Mon Sep 17 00:00:00 2001

From: Stefan Hajnoczi <stefanha@redhat.com>

Date: Tue, 16 Jul 2019 13:22:14 +0200

Subject: [PATCH 21/23] qdev: add qdev_add_vm_change_state_handler()

RH-Author: Stefan Hajnoczi <stefanha@redhat.com>

Message-id: <20190716132215.18503-3-stefanha@redhat.com>

Patchwork-id: 89537

O-Subject: [RHEL-7.8 RHEL-7.7.z qemu-kvm-rhev PATCH 2/3] qdev: add qdev_add_vm_change_state_handler()

Bugzilla: 1673546

RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>

RH-Acked-by: John Snow <jsnow@redhat.com>

RH-Acked-by: Kevin Wolf <kwolf@redhat.com>

Children sometimes depend on their parent's vm change state handler

having completed.  Add a vm change state handler API for devices that

guarantees tree depth ordering.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

(cherry picked from commit e965ffa70ac8ddc334dd5990f6907789bd9e6af6)

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 hw/core/Makefile.objs             |  1 +

 hw/core/vm-change-state-handler.c | 61 +++++++++++++++++++++++++++++++++++++++

 include/hw/qdev-core.h            |  5 ++++

 3 files changed, 67 insertions(+)

 create mode 100644 hw/core/vm-change-state-handler.c

diff --git a/hw/core/Makefile.objs b/hw/core/Makefile.objs

index e967fb2..28531b0 100644

--- a/hw/core/Makefile.objs

+++ b/hw/core/Makefile.objs

@@ -7,6 +7,7 @@ common-obj-$(CONFIG_SOFTMMU) += fw-path-provider.o

 common-obj-y += irq.o

 common-obj-y += hotplug.o

 common-obj-$(CONFIG_SOFTMMU) += nmi.o

+common-obj-$(CONFIG_SOFTMMU) += vm-change-state-handler.o

 common-obj-$(CONFIG_EMPTY_SLOT) += empty_slot.o

 common-obj-$(CONFIG_XILINX_AXI) += stream.o

diff --git a/hw/core/vm-change-state-handler.c b/hw/core/vm-change-state-handler.c

new file mode 100644

index 0000000..f814813

--- /dev/null

+++ b/hw/core/vm-change-state-handler.c

@@ -0,0 +1,61 @@

+/*

+ *  qdev vm change state handlers

+ *

+ *  This program is free software; you can redistribute it and/or modify

+ *  it under the terms of the GNU General Public License as published by

+ *  the Free Software Foundation; either version 2 of the License,

+ *  or (at your option) any later version.

+ *

+ *  This program is distributed in the hope that it will be useful,

+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of

+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+ *  GNU General Public License for more details.

+ *

+ *  You should have received a copy of the GNU General Public License

+ *  along with this program; if not, see <http://www.gnu.org/licenses/>.

+ */

+

+#include "qemu/osdep.h"

+#include "hw/qdev.h"

+

+static int qdev_get_dev_tree_depth(DeviceState *dev)

+{

+    int depth;

+

+    for (depth = 0; dev; depth++) {

+        BusState *bus = dev->parent_bus;

+

+        if (!bus) {

+            break;

+        }

+

+        dev = bus->parent;

+    }

+

+    return depth;

+}

+

+/**

+ * qdev_add_vm_change_state_handler:

+ * @dev: the device that owns this handler

+ * @cb: the callback function to be invoked

+ * @opaque: user data passed to the callback function

+ *

+ * This function works like qemu_add_vm_change_state_handler() except callbacks

+ * are invoked in qdev tree depth order.  Ordering is desirable when callbacks

+ * of children depend on their parent's callback having completed first.

+ *

+ * For example, when qdev_add_vm_change_state_handler() is used, a host

+ * controller's callback is invoked before the children on its bus when the VM

+ * starts running.  The order is reversed when the VM stops running.

+ *

+ * Returns: an entry to be freed with qemu_del_vm_change_state_handler()

+ */

+VMChangeStateEntry *qdev_add_vm_change_state_handler(DeviceState *dev,

+                                                     VMChangeStateHandler *cb,

+                                                     void *opaque)

+{

+    int depth = qdev_get_dev_tree_depth(dev);

+

+    return qemu_add_vm_change_state_handler_prio(cb, opaque, depth);

+}

diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h

index 9453588..ff8bd5a 100644

--- a/include/hw/qdev-core.h

+++ b/include/hw/qdev-core.h

@@ -6,6 +6,7 @@

 #include "qom/object.h"

 #include "hw/irq.h"

 #include "hw/hotplug.h"

+#include "sysemu/sysemu.h"

 enum {

     DEV_NVECTORS_UNSPECIFIED = -1,

@@ -446,4 +447,8 @@ static inline bool qbus_is_hotpluggable(BusState *bus)

 void device_listener_register(DeviceListener *listener);

 void device_listener_unregister(DeviceListener *listener);

+VMChangeStateEntry *qdev_add_vm_change_state_handler(DeviceState *dev,

+                                                     VMChangeStateHandler *cb,

+                                                     void *opaque);

+

 #endif

-- 

1.8.3.1