From patchwork Tue Jun 6 18:29:11 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Borntraeger X-Patchwork-Id: 9769591 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B864B60364 for ; Tue, 6 Jun 2017 18:30:47 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B101B283BA for ; Tue, 6 Jun 2017 18:30:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A54B0283BD; Tue, 6 Jun 2017 18:30:47 +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=-6.9 required=2.0 tests=BAYES_00,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 79854283BA for ; Tue, 6 Jun 2017 18:30:46 +0000 (UTC) Received: from localhost ([::1]:39662 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dIJFd-0006PK-Cv for patchwork-qemu-devel@patchwork.kernel.org; Tue, 06 Jun 2017 14:30:45 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50684) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dIJEP-0006M9-F4 for qemu-devel@nongnu.org; Tue, 06 Jun 2017 14:29:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dIJEK-00032S-HL for qemu-devel@nongnu.org; Tue, 06 Jun 2017 14:29:29 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:53741) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dIJEK-000323-7q for qemu-devel@nongnu.org; Tue, 06 Jun 2017 14:29:24 -0400 Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v56IT73x068512 for ; Tue, 6 Jun 2017 14:29:22 -0400 Received: from e06smtp11.uk.ibm.com (e06smtp11.uk.ibm.com [195.75.94.107]) by mx0a-001b2d01.pphosted.com with ESMTP id 2awynhxd2c-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 06 Jun 2017 14:29:22 -0400 Received: from localhost by e06smtp11.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Tue, 6 Jun 2017 19:29:18 +0100 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v56ITIgu18678060; Tue, 6 Jun 2017 18:29:18 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C09D552041; Tue, 6 Jun 2017 18:26:09 +0100 (BST) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTPS id A222B5203F; Tue, 6 Jun 2017 18:26:09 +0100 (BST) Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 25651) id A65EF20F677; Tue, 6 Jun 2017 20:29:17 +0200 (CEST) From: Christian Borntraeger To: Peter Maydell Date: Tue, 6 Jun 2017 20:29:11 +0200 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1496773755-53343-1-git-send-email-borntraeger@de.ibm.com> References: <1496773755-53343-1-git-send-email-borntraeger@de.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17060618-0040-0000-0000-000003C31B38 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17060618-0041-0000-0000-0000205AEFB7 Message-Id: <1496773755-53343-2-git-send-email-borntraeger@de.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-06-06_13:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1703280000 definitions=main-1706060316 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] [fuzzy] X-Received-From: 148.163.156.1 Subject: [Qemu-devel] [PATCH 1/5] s390x/css: catch section mismatch on load 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: Alexander Graf , Halil Pasic , qemu-devel , qemu-stable@nongnu.org, Christian Borntraeger , Cornelia Huck , Richard Henderson Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Halil Pasic Prior to the virtio-ccw-2.7 machine (and commit 2a79eb1a), our virtio devices residing under the virtual-css bus do not have qdev_path based migration stream identifiers (because their qdev_path is NULL). The ids are instead generated when the device is registered as a composition of the so called idstr, which takes the vmsd name as its value, and an instance_id, which is which is calculated as a maximal instance_id registered with the same idstr plus one, or zero (if none was registered previously). That means, under certain circumstances, one device might try, and even succeed, to load the state of a different device. This can lead to trouble. Let us fail the migration if the above problem is detected during load. How to reproduce the problem: 1) start qemu-system-s390x making sure you have the following devices defined on your command line: -device virtio-rng-ccw,id=rng1,devno=fe.0.0001 -device virtio-rng-ccw,id=rng2,devno=fe.0.0002 2) detach the devices and reattach in reverse order using the monitor: (qemu) device_del rng1 (qemu) device_del rng2 (qemu) device_add virtio-rng-ccw,id=rng2,devno=fe.0.0002 (qemu) device_add virtio-rng-ccw,id=rng1,devno=fe.0.0001 3) save the state of the vm into a temporary file and quit QEMU: (qemu) migrate "exec:gzip -c > /tmp/tmp_vmstate.gz" (qemu) q 4) use your command line from step 1 with -incoming "exec:gzip -c -d /tmp/tmp_vmstate.gz" appended to reproduce the problem (while trying to to load the saved vm) CC: qemu-stable@nongnu.org Signed-off-by: Halil Pasic Reviewed-by: Dong Jia Shi Reviewed-by: Cornelia Huck Message-Id: <20170518111405.56947-1-pasic@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger --- hw/s390x/css.c | 14 ++++++++++++++ hw/s390x/virtio-ccw.c | 6 +++++- 2 files changed, 19 insertions(+), 1 deletion(-) diff --git a/hw/s390x/css.c b/hw/s390x/css.c index 1e2f26b..cc76c53 100644 --- a/hw/s390x/css.c +++ b/hw/s390x/css.c @@ -15,6 +15,7 @@ #include "hw/qdev.h" #include "qemu/error-report.h" #include "qemu/bitops.h" +#include "qemu/error-report.h" #include "exec/address-spaces.h" #include "cpu.h" #include "hw/s390x/ioinst.h" @@ -1800,13 +1801,26 @@ void subch_device_save(SubchDev *s, QEMUFile *f) int subch_device_load(SubchDev *s, QEMUFile *f) { SubchDev *old_s; + Error *err = NULL; uint16_t old_schid = s->schid; + uint16_t old_devno = s->devno; int i; s->cssid = qemu_get_byte(f); s->ssid = qemu_get_byte(f); s->schid = qemu_get_be16(f); s->devno = qemu_get_be16(f); + if (s->devno != old_devno) { + /* Only possible if machine < 2.7 (no css_dev_path) */ + + error_setg(&err, "%x != %x", old_devno, s->devno); + error_append_hint(&err, "Devno mismatch, tried to load wrong section!" + " Likely reason: some sequences of plug and unplug" + " can break migration for machine versions prior to" + " 2.7 (known design flaw).\n"); + error_report_err(err); + return -EINVAL; + } /* Re-assign subch. */ if (old_schid != s->schid) { old_s = channel_subsys.css[s->cssid]->sch_set[s->ssid]->sch[old_schid]; diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c index e6a6f74..90d37cb 100644 --- a/hw/s390x/virtio-ccw.c +++ b/hw/s390x/virtio-ccw.c @@ -1279,9 +1279,13 @@ static int virtio_ccw_load_config(DeviceState *d, QEMUFile *f) SubchDev *s = ccw_dev->sch; VirtIODevice *vdev = virtio_ccw_get_vdev(s); int len; + int ret; s->driver_data = dev; - subch_device_load(s, f); + ret = subch_device_load(s, f); + if (ret) { + return ret; + } /* Re-fill subch_id after loading the subchannel states.*/ if (ck->refill_ids) { ck->refill_ids(ccw_dev);