From 032fc7e1bc37a62ea45d77be9e96847a58bb25c9 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi 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 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 RH-Acked-by: John Snow RH-Acked-by: Kevin Wolf 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 Signed-off-by: Kevin Wolf (cherry picked from commit e965ffa70ac8ddc334dd5990f6907789bd9e6af6) Signed-off-by: Stefan Hajnoczi Signed-off-by: Miroslav Rezanina --- 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 . + */ + +#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