From patchwork Thu Dec 15 15:43:30 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Halil Pasic X-Patchwork-Id: 9476455 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 6381F60571 for ; Thu, 15 Dec 2016 15:44:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 567B5287C0 for ; Thu, 15 Dec 2016 15:44:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4B0D2287C2; Thu, 15 Dec 2016 15:44:17 +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 88073287C0 for ; Thu, 15 Dec 2016 15:44:15 +0000 (UTC) Received: from localhost ([::1]:55334 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cHYCa-00063u-1R for patchwork-qemu-devel@patchwork.kernel.org; Thu, 15 Dec 2016 10:44:12 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47094) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cHYCC-00060O-B9 for qemu-devel@nongnu.org; Thu, 15 Dec 2016 10:43:49 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cHYC9-0005Z6-86 for qemu-devel@nongnu.org; Thu, 15 Dec 2016 10:43:48 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:43935 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 1cHYC9-0005YE-3Q for qemu-devel@nongnu.org; Thu, 15 Dec 2016 10:43:45 -0500 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.17/8.16.0.17) with SMTP id uBFFYEwT112512 for ; Thu, 15 Dec 2016 10:43:43 -0500 Received: from e06smtp09.uk.ibm.com (e06smtp09.uk.ibm.com [195.75.94.105]) by mx0b-001b2d01.pphosted.com with ESMTP id 27bvg27ktd-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Thu, 15 Dec 2016 10:43:43 -0500 Received: from localhost by e06smtp09.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 15 Dec 2016 15:43:41 -0000 Received: from d06dlp01.portsmouth.uk.ibm.com (9.149.20.13) by e06smtp09.uk.ibm.com (192.168.101.139) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Thu, 15 Dec 2016 15:43:39 -0000 Received: from b06cxnps4074.portsmouth.uk.ibm.com (d06relay11.portsmouth.uk.ibm.com [9.149.109.196]) by d06dlp01.portsmouth.uk.ibm.com (Postfix) with ESMTP id EDA5117D8042; Thu, 15 Dec 2016 15:46:16 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id uBFFhdYt3277100; Thu, 15 Dec 2016 15:43:39 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A5DE5A4059; Thu, 15 Dec 2016 14:41:45 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 749D4A404D; Thu, 15 Dec 2016 14:41:45 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Thu, 15 Dec 2016 14:41:45 +0000 (GMT) From: Halil Pasic To: qemu-devel@nongnu.org Date: Thu, 15 Dec 2016 16:43:30 +0100 X-Mailer: git-send-email 2.8.4 X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16121515-0036-0000-0000-0000027817E8 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16121515-0037-0000-0000-000013A6ABF0 Message-Id: <20161215154330.700-1-pasic@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2016-12-15_09:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1612050000 definitions=main-1612150243 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] virtio: fix vring->inuse recalc after migr 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: Halil Pasic , qemu-stable@nongnu.org, Stefan Hajnoczi Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Correct recalculation of vring->inuse after migration for the corner case where the avail_idx has already wrapped but used_idx not yet. Signed-off-by: Halil Pasic Fixes: bccdef6b ("virtio: recalculate vq->inuse after migration") CC: qemu-stable@nongnu.org --- I think we could also change the type of inuse to uint16_t. Would this be considered a good idea? --- hw/virtio/virtio.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 1af2de2..089c6f6 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -1855,9 +1855,12 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) /* * Some devices migrate VirtQueueElements that have been popped * from the avail ring but not yet returned to the used ring. + * Cast to uint16_t is OK because max ring size is 0x8000. Thus + * no the size of largest array indexable by an integral type + * can not be represented by the same type problem. */ - vdev->vq[i].inuse = vdev->vq[i].last_avail_idx - - vdev->vq[i].used_idx; + vdev->vq[i].inuse = (uint16_t)(vdev->vq[i].last_avail_idx - + vdev->vq[i].used_idx); if (vdev->vq[i].inuse > vdev->vq[i].vring.num) { error_report("VQ %d size 0x%x < last_avail_idx 0x%x - " "used_idx 0x%x",