From patchwork Wed Jul 25 03:31:06 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liu Ping Fan X-Patchwork-Id: 1234301 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 197B6DFFC1 for ; Wed, 25 Jul 2012 03:31:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932723Ab2GYDbp (ORCPT ); Tue, 24 Jul 2012 23:31:45 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:49229 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932710Ab2GYDbX (ORCPT ); Tue, 24 Jul 2012 23:31:23 -0400 Received: by pbbrp8 with SMTP id rp8so675132pbb.19 for ; Tue, 24 Jul 2012 20:31:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; bh=8zqU3J4y+70KyG/0eTh+JdryGceseIjKgQHmQ0Smahk=; b=KMW0FS92eGIt4JS1gQr4bGpX05XGR0SI/tFVTiWqF8rmDXh56sZFnRItx45jZ6K+pr A2ohZ+b+Iav4Z/bOY4I7telKWK1UY3122BdqPSszqww3YtCLLVsUX1Yn1xxVNlbcmKxl zzpULt70cdMccorEnzIxgq/KCt/ISG5/O+4eEgHVOyRvMGIKDozRc+nMURSybRzfpSkX dj1l+Yz02PAMzWEcxDC/wB8DLwU2Nl+R75DwXHnqi+NmdctLQV1TpRyzGczh9MbxQy4X c59SHw4ggk0Eke4aaZTWmKZBRFcZjmAfzXU0hGO0ZpJpXp+u6v6ApTypWf3SsWkW0pTl xFCA== Received: by 10.68.203.67 with SMTP id ko3mr8551008pbc.126.1343187083294; Tue, 24 Jul 2012 20:31:23 -0700 (PDT) Received: from localhost ([202.108.130.138]) by mx.google.com with ESMTPS id ot4sm13424097pbb.65.2012.07.24.20.31.21 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 24 Jul 2012 20:31:22 -0700 (PDT) From: Liu Ping Fan To: qemu-devel@nongnu.org Cc: kvm@vger.kernel.org, Anthony Liguori , Avi Kivity , Jan Kiszka , Marcelo Tosatti , Stefan Hajnoczi Subject: [PATCH 1/5] qom: adopt rwlock to protect accessing dev from removing it Date: Wed, 25 Jul 2012 11:31:06 +0800 Message-Id: <1343187070-27371-2-git-send-email-qemulist@gmail.com> X-Mailer: git-send-email 1.7.4.4 In-Reply-To: <1343187070-27371-1-git-send-email-qemulist@gmail.com> References: <1343187070-27371-1-git-send-email-qemulist@gmail.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Liu Ping Fan rwlock: qemu_device_tree_mutex rd side: --device_del(destruction of device will be postphoned until unplug ack from guest), --pci hot-unplug --iteration (qdev_reset_all) wr side: --device_add Signed-off-by: Liu Ping Fan --- hw/pci-hotplug.c | 4 ++++ hw/qdev-monitor.c | 17 ++++++++++++++++- hw/qdev.c | 2 ++ 3 files changed, 22 insertions(+), 1 deletions(-) diff --git a/hw/pci-hotplug.c b/hw/pci-hotplug.c index e7fb780..b3b88c1 100644 --- a/hw/pci-hotplug.c +++ b/hw/pci-hotplug.c @@ -265,9 +265,11 @@ static int pci_device_hot_remove(Monitor *mon, const char *pci_addr) return -1; } + qemu_rwlock_rdlock_devtree(); d = pci_find_device(pci_find_root_bus(dom), bus, PCI_DEVFN(slot, 0)); if (!d) { monitor_printf(mon, "slot %d empty\n", slot); + qemu_rwlock_unlock_devtree(); return -1; } @@ -275,9 +277,11 @@ static int pci_device_hot_remove(Monitor *mon, const char *pci_addr) if (error_is_set(&local_err)) { monitor_printf(mon, "%s\n", error_get_pretty(local_err)); error_free(local_err); + qemu_rwlock_unlock_devtree(); return -1; } + qemu_rwlock_unlock_devtree(); return 0; } diff --git a/hw/qdev-monitor.c b/hw/qdev-monitor.c index 7915b45..8aec067 100644 --- a/hw/qdev-monitor.c +++ b/hw/qdev-monitor.c @@ -429,14 +429,18 @@ DeviceState *qdev_device_add(QemuOpts *opts) /* find bus */ path = qemu_opt_get(opts, "bus"); + + qemu_rwlock_wrlock_devtree(); if (path != NULL) { bus = qbus_find(path); if (!bus) { + qemu_rwlock_unlock_devtree(); return NULL; } if (strcmp(object_get_typename(OBJECT(bus)), k->bus_type) != 0) { qerror_report(QERR_BAD_BUS_FOR_DEVICE, driver, object_get_typename(OBJECT(bus))); + qemu_rwlock_unlock_devtree(); return NULL; } } else { @@ -444,11 +448,13 @@ DeviceState *qdev_device_add(QemuOpts *opts) if (!bus) { qerror_report(QERR_NO_BUS_FOR_DEVICE, driver, k->bus_type); + qemu_rwlock_unlock_devtree(); return NULL; } } if (qdev_hotplug && !bus->allow_hotplug) { qerror_report(QERR_BUS_NO_HOTPLUG, bus->name); + qemu_rwlock_unlock_devtree(); return NULL; } @@ -466,6 +472,7 @@ DeviceState *qdev_device_add(QemuOpts *opts) } if (qemu_opt_foreach(opts, set_property, qdev, 1) != 0) { qdev_free(qdev); + qemu_rwlock_unlock_devtree(); return NULL; } if (qdev->id) { @@ -478,6 +485,8 @@ DeviceState *qdev_device_add(QemuOpts *opts) OBJECT(qdev), NULL); g_free(name); } + qemu_rwlock_unlock_devtree(); + if (qdev_init(qdev) < 0) { qerror_report(QERR_DEVICE_INIT_FAILED, driver); return NULL; @@ -600,13 +609,19 @@ void qmp_device_del(const char *id, Error **errp) { DeviceState *dev; + /* protect against unplug ack from guest, where we really remove device + * from system + */ + qemu_rwlock_rdlock_devtree(); dev = qdev_find_recursive(sysbus_get_default(), id); if (NULL == dev) { error_set(errp, QERR_DEVICE_NOT_FOUND, id); + qemu_rwlock_unlock_devtree(); return; } - + /* Just remove from system, and drop refcnt there*/ qdev_unplug(dev, errp); + qemu_rwlock_unlock_devtree(); } void qdev_machine_init(void) diff --git a/hw/qdev.c b/hw/qdev.c index af54467..ac55e45 100644 --- a/hw/qdev.c +++ b/hw/qdev.c @@ -230,7 +230,9 @@ static int qbus_reset_one(BusState *bus, void *opaque) void qdev_reset_all(DeviceState *dev) { + qemu_rwlock_rdlock_devtree(); qdev_walk_children(dev, qdev_reset_one, qbus_reset_one, NULL); + qemu_rwlock_unlock_devtree(); } void qbus_reset_all_fn(void *opaque)