From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41881) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gXTpA-0005xT-Ve for qemu-devel@nongnu.org; Thu, 13 Dec 2018 11:26:57 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gXTp7-0001mB-M8 for qemu-devel@nongnu.org; Thu, 13 Dec 2018 11:26:56 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:49766) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gXTp7-0001k6-D4 for qemu-devel@nongnu.org; Thu, 13 Dec 2018 11:26:53 -0500 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id wBDGOSb0033748 for ; Thu, 13 Dec 2018 11:26:52 -0500 Received: from e16.ny.us.ibm.com (e16.ny.us.ibm.com [129.33.205.206]) by mx0a-001b2d01.pphosted.com with ESMTP id 2pbtgt9wd8-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 13 Dec 2018 11:26:51 -0500 Received: from localhost by e16.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 13 Dec 2018 16:26:50 -0000 From: Tony Krowiak Date: Thu, 13 Dec 2018 11:26:42 -0500 Message-Id: <1544718402-8703-1-git-send-email-akrowiak@linux.ibm.com> Subject: [Qemu-devel] [PATCH v2] qdev/core: Can not replug device on bus that allows one device List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: pasic@linux.ibm.com, mammedo@redhat.com, Tony Krowiak If the maximum number of devices allowed on a bus is 1 and a device which is plugged into the bus is subsequently unplugged, attempting to replug the device fails with error "Bus 'xxx' does not support hotplugging". The "error" is detected in the qbus_is_full(BusState *bus) function (qdev_monitor.c) because bus->max_index >= bus_class->max_dev. The root of the problem is that the bus->max_index is not decremented when a device is unplugged from the bus. This patch fixes that problem. Signed-off-by: Tony Krowiak --- 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; } /* -- 2.7.4