From patchwork Mon Dec 17 15:57:30 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anthony Krowiak X-Patchwork-Id: 10733735 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4B17E13AD for ; Mon, 17 Dec 2018 15:58:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3B2AD29F72 for ; Mon, 17 Dec 2018 15:58:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2C2AB2A121; Mon, 17 Dec 2018 15:58:27 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 9DA7029F72 for ; Mon, 17 Dec 2018 15:58:26 +0000 (UTC) Received: from localhost ([::1]:47560 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gYvHl-0004lD-5Q for patchwork-qemu-devel@patchwork.kernel.org; Mon, 17 Dec 2018 10:58:25 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42623) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gYvH7-0004l6-0Z for qemu-devel@nongnu.org; Mon, 17 Dec 2018 10:57:47 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gYvH2-00070T-2j for qemu-devel@nongnu.org; Mon, 17 Dec 2018 10:57:44 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:35638 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gYvH1-0006ze-TT for qemu-devel@nongnu.org; Mon, 17 Dec 2018 10:57:40 -0500 Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id wBHFrVPl129197 for ; Mon, 17 Dec 2018 10:57:38 -0500 Received: from e11.ny.us.ibm.com (e11.ny.us.ibm.com [129.33.205.201]) by mx0a-001b2d01.pphosted.com with ESMTP id 2peee19h79-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 17 Dec 2018 10:57:38 -0500 Received: from localhost by e11.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 17 Dec 2018 15:57:35 -0000 Received: from b01ledav001.gho.pok.ibm.com (b01ledav001.gho.pok.ibm.com [9.57.199.106]) by b01cxnp23032.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id wBHFvYDR15925426 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 17 Dec 2018 15:57:34 GMT Received: from b01ledav001.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EDB7828067; Mon, 17 Dec 2018 15:57:33 +0000 (GMT) Received: from b01ledav001.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C911028068; Mon, 17 Dec 2018 15:57:33 +0000 (GMT) Received: from akrowiak-ThinkPad-P50.endicott.ibm.com (unknown [9.60.75.235]) by b01ledav001.gho.pok.ibm.com (Postfix) with ESMTPS; Mon, 17 Dec 2018 15:57:33 +0000 (GMT) From: Tony Krowiak To: qemu-devel@nongnu.org Date: Mon, 17 Dec 2018 10:57:30 -0500 X-Mailer: git-send-email 2.7.4 X-TM-AS-GCONF: 00 x-cbid: 18121715-2213-0000-0000-0000032C4A43 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010241; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000271; SDB=6.01133098; UDB=6.00589023; IPR=6.00913267; MB=3.00024718; MTD=3.00000008; XFM=3.00000015; UTC=2018-12-17 15:57:36 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18121715-2214-0000-0000-00005CA2EC3C Message-Id: <1545062250-7573-1-git-send-email-akrowiak@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2018-12-17_06:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1812170142 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] [fuzzy] X-Received-From: 148.163.158.5 Subject: [Qemu-devel] [PATCH v3] qdev/core: fix qbus_is_full() 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: pasic@linux.ibm.com, imammedo@redhat.com, Tony Krowiak , pmorel@linux.ibm.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP The qbus_is_full(BusState *bus) function (qdev_monitor.c) compares the max_index value of the BusState structure with the max_dev value of the BusClass structure to determine whether the maximum number of children has been reached for the bus. The problem is, the max_index field of the BusState structure does not necessarily reflect the number of devices that have been plugged into the bus. Whenever a child device is plugged into the bus, the bus's max_index value is assigned to the child device and then incremented. If the child is subsequently unplugged, the value of the max_index does not change and no longer reflects the number of children. When the bus's max_index value reaches the maximum number of devices allowed for the bus (i.e., the max_dev field in the BusClass structure), attempts to plug another device will be rejected claiming that the bus is full -- even if the bus is actually empty. To resolve the problem, a new 'num_children' field is being added to the BusState structure to keep track of the number of children plugged into the bus. It will be incremented when a child is plugged, and decremented when a child is unplugged. Signed-off-by: Tony Krowiak Reviewed-by: Pierre Morel Reviewed-by: Halil Pasic Reviewed-by: Igor Mammedov --- hw/core/qdev.c | 3 +++ include/hw/qdev-core.h | 1 + qdev-monitor.c | 2 +- 3 files changed, 5 insertions(+), 1 deletion(-) diff --git a/hw/core/qdev.c b/hw/core/qdev.c index 6b3cc55b27c2..956923f33520 100644 --- a/hw/core/qdev.c +++ b/hw/core/qdev.c @@ -59,6 +59,8 @@ static void bus_remove_child(BusState *bus, DeviceState *child) snprintf(name, sizeof(name), "child[%d]", kid->index); QTAILQ_REMOVE(&bus->children, kid, sibling); + bus->num_children--; + /* This gives back ownership of kid->child back to us. */ object_property_del(OBJECT(bus), name, NULL); object_unref(OBJECT(kid->child)); @@ -73,6 +75,7 @@ static void bus_add_child(BusState *bus, DeviceState *child) char name[32]; BusChild *kid = g_malloc0(sizeof(*kid)); + bus->num_children++; kid->index = bus->max_index++; kid->child = child; object_ref(OBJECT(kid->child)); diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h index a24d0dd566e3..521f0a947ead 100644 --- a/include/hw/qdev-core.h +++ b/include/hw/qdev-core.h @@ -206,6 +206,7 @@ struct BusState { HotplugHandler *hotplug_handler; int max_index; bool realized; + int num_children; QTAILQ_HEAD(ChildrenHead, BusChild) children; QLIST_ENTRY(BusState) sibling; }; diff --git a/qdev-monitor.c b/qdev-monitor.c index 07147c63bf8b..45a8ba49644c 100644 --- a/qdev-monitor.c +++ b/qdev-monitor.c @@ -414,7 +414,7 @@ static DeviceState *qbus_find_dev(BusState *bus, char *elem) static inline bool qbus_is_full(BusState *bus) { BusClass *bus_class = BUS_GET_CLASS(bus); - return bus_class->max_dev && bus->max_index >= bus_class->max_dev; + return bus_class->max_dev && bus->num_children >= bus_class->max_dev; } /*