qemu/hw/core/hotplug.c
Igor Mammedov 8b5e6caf01 call HotplugHandler->plug() as the last step in device realization
When [2] was fixed it was agreed that adding and calling post_plug()
callback after device_reset() was low risk approach to hotfix issue
right before release. So it was merged instead of moving already
existing plug() callback after device_reset() is called which would
be more risky and require all plug() callbacks audit.

Looking at the current plug() callbacks, it doesn't seem that moving
plug() callback after device_reset() is breaking anything, so here
goes agreed upon [3] proper fix which essentially reverts [1][2]
and moves plug() callback after device_reset().
This way devices always comes to plug() stage, after it's been fully
initialized (including being reset), which fixes race condition [2]
without need for an extra post_plug() callback.

 1. (25e897881 "qdev: add HotplugHandler->post_plug() callback")
 2. (8449bcf94 "virtio-scsi: fix hotplug ->reset() vs event race")
 3. https://www.mail-archive.com/qemu-devel@nongnu.org/msg549915.html

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <1539696820-273275-1-git-send-email-imammedo@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Pierre Morel<pmorel@linux.ibm.com>
Acked-by: Pierre Morel<pmorel@linux.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-19 13:44:12 +02:00

72 lines
1.9 KiB
C

/*
* Hotplug handler interface.
*
* Copyright (c) 2014 Red Hat Inc.
*
* Authors:
* Igor Mammedov <imammedo@redhat.com>,
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "hw/hotplug.h"
#include "qemu/module.h"
void hotplug_handler_pre_plug(HotplugHandler *plug_handler,
DeviceState *plugged_dev,
Error **errp)
{
HotplugHandlerClass *hdc = HOTPLUG_HANDLER_GET_CLASS(plug_handler);
if (hdc->pre_plug) {
hdc->pre_plug(plug_handler, plugged_dev, errp);
}
}
void hotplug_handler_plug(HotplugHandler *plug_handler,
DeviceState *plugged_dev,
Error **errp)
{
HotplugHandlerClass *hdc = HOTPLUG_HANDLER_GET_CLASS(plug_handler);
if (hdc->plug) {
hdc->plug(plug_handler, plugged_dev, errp);
}
}
void hotplug_handler_unplug_request(HotplugHandler *plug_handler,
DeviceState *plugged_dev,
Error **errp)
{
HotplugHandlerClass *hdc = HOTPLUG_HANDLER_GET_CLASS(plug_handler);
if (hdc->unplug_request) {
hdc->unplug_request(plug_handler, plugged_dev, errp);
}
}
void hotplug_handler_unplug(HotplugHandler *plug_handler,
DeviceState *plugged_dev,
Error **errp)
{
HotplugHandlerClass *hdc = HOTPLUG_HANDLER_GET_CLASS(plug_handler);
if (hdc->unplug) {
hdc->unplug(plug_handler, plugged_dev, errp);
}
}
static const TypeInfo hotplug_handler_info = {
.name = TYPE_HOTPLUG_HANDLER,
.parent = TYPE_INTERFACE,
.class_size = sizeof(HotplugHandlerClass),
};
static void hotplug_handler_register_types(void)
{
type_register_static(&hotplug_handler_info);
}
type_init(hotplug_handler_register_types)