From 8b5e6caf01f778a257721cae499392e8f1d55ddb Mon Sep 17 00:00:00 2001 From: Igor Mammedov Date: Tue, 16 Oct 2018 15:33:40 +0200 Subject: 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 Message-Id: <1539696820-273275-1-git-send-email-imammedo@redhat.com> Reviewed-by: Stefan Hajnoczi Tested-by: Pierre Morel Acked-by: Pierre Morel Signed-off-by: Paolo Bonzini --- hw/core/hotplug.c | 10 ---------- hw/core/qdev.c | 16 ++++++---------- hw/scsi/virtio-scsi.c | 11 +---------- 3 files changed, 7 insertions(+), 30 deletions(-) (limited to 'hw') diff --git a/hw/core/hotplug.c b/hw/core/hotplug.c index 2253072d0e..17ac986685 100644 --- a/hw/core/hotplug.c +++ b/hw/core/hotplug.c @@ -35,16 +35,6 @@ void hotplug_handler_plug(HotplugHandler *plug_handler, } } -void hotplug_handler_post_plug(HotplugHandler *plug_handler, - DeviceState *plugged_dev) -{ - HotplugHandlerClass *hdc = HOTPLUG_HANDLER_GET_CLASS(plug_handler); - - if (hdc->post_plug) { - hdc->post_plug(plug_handler, plugged_dev); - } -} - void hotplug_handler_unplug_request(HotplugHandler *plug_handler, DeviceState *plugged_dev, Error **errp) diff --git a/hw/core/qdev.c b/hw/core/qdev.c index 046d8f1f76..6b3cc55b27 100644 --- a/hw/core/qdev.c +++ b/hw/core/qdev.c @@ -832,14 +832,6 @@ static void device_set_realized(Object *obj, bool value, Error **errp) DEVICE_LISTENER_CALL(realize, Forward, dev); - if (hotplug_ctrl) { - hotplug_handler_plug(hotplug_ctrl, dev, &local_err); - } - - if (local_err != NULL) { - goto post_realize_fail; - } - /* * always free/re-initialize here since the value cannot be cleaned up * in device_unrealize due to its usage later on in the unplug path @@ -869,8 +861,12 @@ static void device_set_realized(Object *obj, bool value, Error **errp) dev->pending_deleted_event = false; if (hotplug_ctrl) { - hotplug_handler_post_plug(hotplug_ctrl, dev); - } + hotplug_handler_plug(hotplug_ctrl, dev, &local_err); + if (local_err != NULL) { + goto child_realize_fail; + } + } + } else if (!value && dev->realized) { Error **local_errp = NULL; QLIST_FOREACH(bus, &dev->child_bus, sibling) { diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c index 5a3057d1f8..3aa99717e2 100644 --- a/hw/scsi/virtio-scsi.c +++ b/hw/scsi/virtio-scsi.c @@ -797,16 +797,8 @@ static void virtio_scsi_hotplug(HotplugHandler *hotplug_dev, DeviceState *dev, virtio_scsi_acquire(s); blk_set_aio_context(sd->conf.blk, s->ctx); virtio_scsi_release(s); - } -} -/* Announce the new device after it has been plugged */ -static void virtio_scsi_post_hotplug(HotplugHandler *hotplug_dev, - DeviceState *dev) -{ - VirtIODevice *vdev = VIRTIO_DEVICE(hotplug_dev); - VirtIOSCSI *s = VIRTIO_SCSI(vdev); - SCSIDevice *sd = SCSI_DEVICE(dev); + } if (virtio_vdev_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG)) { virtio_scsi_acquire(s); @@ -976,7 +968,6 @@ static void virtio_scsi_class_init(ObjectClass *klass, void *data) vdc->start_ioeventfd = virtio_scsi_dataplane_start; vdc->stop_ioeventfd = virtio_scsi_dataplane_stop; hc->plug = virtio_scsi_hotplug; - hc->post_plug = virtio_scsi_post_hotplug; hc->unplug = virtio_scsi_hotunplug; } -- cgit v1.2.3