From nobody Wed Oct 29 20:43:06 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; 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 208.118.235.17 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 (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 1526545402168801.8687931875648; Thu, 17 May 2018 01:23:22 -0700 (PDT) Received: from localhost ([::1]:41943 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fJEBw-00084g-5G for importer@patchew.org; Thu, 17 May 2018 04:23:16 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49194) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fJE4b-0002TE-O4 for qemu-devel@nongnu.org; Thu, 17 May 2018 04:15:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fJE4a-0002rD-HL for qemu-devel@nongnu.org; Thu, 17 May 2018 04:15:41 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:50690 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fJE4a-0002qx-9z; Thu, 17 May 2018 04:15:40 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id ACCFE40711C1; Thu, 17 May 2018 08:15:39 +0000 (UTC) Received: from t460s.redhat.com (ovpn-117-24.ams2.redhat.com [10.36.117.24]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2A258215CDB7; Thu, 17 May 2018 08:15:37 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Date: Thu, 17 May 2018 10:15:16 +0200 Message-Id: <20180517081527.14410-4-david@redhat.com> In-Reply-To: <20180517081527.14410-1-david@redhat.com> References: <20180517081527.14410-1-david@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Thu, 17 May 2018 08:15:39 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Thu, 17 May 2018 08:15:39 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'david@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH v4 03/14] 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: Pankaj Gupta , Eduardo Habkost , "Michael S . Tsirkin" , Cornelia Huck , David Hildenbrand , Markus Armbruster , Alexander Graf , Christian Borntraeger , qemu-s390x@nongnu.org, qemu-ppc@nongnu.org, Paolo Bonzini , Marcel Apfelbaum , Igor Mammedov , Luiz Capitulino , David Gibson , Richard Henderson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 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) } } Signed-off-by: Igor Mammedov Signed-off-by: David Hildenbrand Reviewed-by: David Gibson --- 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 f6f92473b8..885286f579 100644 --- a/hw/core/qdev.c +++ b/hw/core/qdev.c @@ -261,12 +261,10 @@ 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 9453588160..e6a8eca558 100644 --- a/include/hw/qdev-core.h +++ b/include/hw/qdev-core.h @@ -286,6 +286,17 @@ 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 2.14.3