From nobody Mon Feb 9 00:01:40 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1551357615985238.77196463734674; Thu, 28 Feb 2019 04:40:15 -0800 (PST) Received: from localhost ([127.0.0.1]:37391 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gzKyw-00023V-Qc for importer@patchew.org; Thu, 28 Feb 2019 07:40:10 -0500 Received: from eggs.gnu.org ([209.51.188.92]:51639) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gzKoP-0002LX-92 for qemu-devel@nongnu.org; Thu, 28 Feb 2019 07:29:20 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gzKoO-00082T-Cs for qemu-devel@nongnu.org; Thu, 28 Feb 2019 07:29:17 -0500 Received: from mx1.redhat.com ([209.132.183.28]:4945) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gzKoO-00082I-4N; Thu, 28 Feb 2019 07:29:16 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 41D273114305; Thu, 28 Feb 2019 12:29:15 +0000 (UTC) Received: from t460s.redhat.com (ovpn-116-115.ams2.redhat.com [10.36.116.115]) by smtp.corp.redhat.com (Postfix) with ESMTP id 76CBF1001E60; Thu, 28 Feb 2019 12:29:09 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Date: Thu, 28 Feb 2019 13:28:48 +0100 Message-Id: <20190228122849.4296-3-david@redhat.com> In-Reply-To: <20190228122849.4296-1-david@redhat.com> References: <20190228122849.4296-1-david@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.40]); Thu, 28 Feb 2019 12:29:15 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 2/3] qdev: Let machine hotplug handler to override bus hotplug handler X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Laurent Vivier , Pankaj Gupta , Collin Walling , Eduardo Habkost , Pierre Morel , "Michael S . Tsirkin" , Cornelia Huck , David Hildenbrand , Michael Roth , Greg Kurz , Halil Pasic , Christian Borntraeger , qemu-s390x@nongnu.org, qemu-ppc@nongnu.org, Paolo Bonzini , Igor Mammedov , Richard Henderson , Eric Auger , David Gibson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Igor Mammedov it will allow to return another hotplug handler than the default one for a specific bus based device type. Which is needed to handle non trivial plug/unplug sequences that need the access to resources configured outside of bus where device is attached. That will allow for returned hotplug handler to orchestrate wiring in arbitrary order, by chaining other hotplug handlers when it's needed. PS: It could be used for hybrid virtio-mem and virtio-pmem devices where it will return machine as hotplug handler which will do necessary wiring at machine level and then pass control down the chain to bus specific hotplug handler. Example of top level hotplug handler override and custom plug sequence: some_machine_get_hotplug_handler(machine){ if (object_dynamic_cast(OBJECT(dev), TYPE_SOME_BUS_DEVICE)) { return HOTPLUG_HANDLER(machine); } return NULL; } some_machine_device_plug(hotplug_dev, dev) { if (object_dynamic_cast(OBJECT(dev), TYPE_SOME_BUS_DEVICE)) { /* do machine specific initialization */ some_machine_init_special_device(dev) /* pass control to bus specific handler */ hotplug_handler_plug(dev->parent_bus->hotplug_handler, dev) } } Reviewed-by: David Gibson Signed-off-by: Igor Mammedov Signed-off-by: David Hildenbrand --- hw/core/qdev.c | 6 ++---- include/hw/qdev-core.h | 11 +++++++++++ 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/hw/core/qdev.c b/hw/core/qdev.c index 278cc094ec..7ad45c0bd6 100644 --- a/hw/core/qdev.c +++ b/hw/core/qdev.c @@ -235,12 +235,10 @@ HotplugHandler *qdev_get_machine_hotplug_handler(Devi= ceState *dev) =20 HotplugHandler *qdev_get_hotplug_handler(DeviceState *dev) { - HotplugHandler *hotplug_ctrl; + HotplugHandler *hotplug_ctrl =3D qdev_get_machine_hotplug_handler(dev); =20 - if (dev->parent_bus && dev->parent_bus->hotplug_handler) { + if (hotplug_ctrl =3D=3D NULL && dev->parent_bus) { hotplug_ctrl =3D dev->parent_bus->hotplug_handler; - } else { - hotplug_ctrl =3D qdev_get_machine_hotplug_handler(dev); } return hotplug_ctrl; } diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h index e70a4bfa49..52562555cd 100644 --- a/include/hw/qdev-core.h +++ b/include/hw/qdev-core.h @@ -281,6 +281,17 @@ void qdev_init_nofail(DeviceState *dev); void qdev_set_legacy_instance_id(DeviceState *dev, int alias_id, int required_for_version); HotplugHandler *qdev_get_machine_hotplug_handler(DeviceState *dev); +/** + * qdev_get_hotplug_handler: Get handler responsible for device wiring + * + * Find HOTPLUG_HANDLER for @dev that provides [pre|un]plug callbacks for = it. + * + * Note: in case @dev has a parent bus, it will be returned as handler unl= ess + * machine handler overrides it. + * + * Returns: pointer to object that implements TYPE_HOTPLUG_HANDLER interfa= ce + * or NULL if there aren't any. + */ HotplugHandler *qdev_get_hotplug_handler(DeviceState *dev); void qdev_unplug(DeviceState *dev, Error **errp); void qdev_simple_device_unplug_cb(HotplugHandler *hotplug_dev, --=20 2.17.2