From nobody Tue Feb 10 19:48:03 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1508038790904422.2395411319043; Sat, 14 Oct 2017 20:39:50 -0700 (PDT) Received: from localhost ([::1]:56019 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e3ZmC-00071R-54 for importer@patchew.org; Sat, 14 Oct 2017 23:39:44 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49318) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e3ZX0-00032l-Rv for qemu-devel@nongnu.org; Sat, 14 Oct 2017 23:24:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e3ZWz-0007BG-Kz for qemu-devel@nongnu.org; Sat, 14 Oct 2017 23:24:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50788) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1e3ZWz-0007Ao-ED for qemu-devel@nongnu.org; Sat, 14 Oct 2017 23:24:01 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 886C013A4E; Sun, 15 Oct 2017 03:24:00 +0000 (UTC) Received: from redhat.com (ovpn-120-178.rdu2.redhat.com [10.10.120.178]) by smtp.corp.redhat.com (Postfix) with SMTP id 4D3DE692BF; Sun, 15 Oct 2017 03:23:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 886C013A4E Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=mst@redhat.com Date: Sun, 15 Oct 2017 06:23:58 +0300 From: "Michael S. Tsirkin" To: qemu-devel@nongnu.org Message-ID: <1508036858-13479-23-git-send-email-mst@redhat.com> References: <1508036858-13479-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1508036858-13479-1-git-send-email-mst@redhat.com> X-Mutt-Fcc: =sent X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Sun, 15 Oct 2017 03:24:00 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 22/26] virtio: fix descriptor counting in virtqueue_pop 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: Peter Maydell , Hans Middelhoek , Wolfgang Bumiller Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Wolfgang Bumiller While changing the s/g list allocation, commit 3b3b0628 also changed the descriptor counting to count iovec entries as split by cpu_physical_memory_map(). Previously only the actual descriptor entries were counted and the split into the iovec happened afterwards in virtqueue_map(). Count the entries again instead to avoid erroneous "Looped descriptor" errors. Reported-by: Hans Middelhoek Link: https://forum.proxmox.com/threads/vm-crash-with-memory-hotplug.35904/ Fixes: 3b3b0628217e ("virtio: slim down allocation of VirtQueueElements") Signed-off-by: Wolfgang Bumiller Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/virtio/virtio.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 311929e..5884ce3 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -834,7 +834,7 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz) int64_t len; VirtIODevice *vdev =3D vq->vdev; VirtQueueElement *elem =3D NULL; - unsigned out_num, in_num; + unsigned out_num, in_num, elem_entries; hwaddr addr[VIRTQUEUE_MAX_SIZE]; struct iovec iov[VIRTQUEUE_MAX_SIZE]; VRingDesc desc; @@ -852,7 +852,7 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz) smp_rmb(); =20 /* When we start there are none of either input nor output. */ - out_num =3D in_num =3D 0; + out_num =3D in_num =3D elem_entries =3D 0; =20 max =3D vq->vring.num; =20 @@ -922,7 +922,7 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz) } =20 /* If we've got too many, that implies a descriptor loop. */ - if ((in_num + out_num) > max) { + if (++elem_entries > max) { virtio_error(vdev, "Looped descriptor"); goto err_undo_map; } --=20 MST