From nobody Thu May 2 17:39:58 2024 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 (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 1511841826398813.4204705435104; Mon, 27 Nov 2017 20:03:46 -0800 (PST) Received: from localhost ([::1]:35774 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eJX7M-0003Xq-OQ for importer@patchew.org; Mon, 27 Nov 2017 23:03:32 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33102) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eJX5Q-0001x8-3p for qemu-devel@nongnu.org; Mon, 27 Nov 2017 23:01:32 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eJX5L-0000M8-LX for qemu-devel@nongnu.org; Mon, 27 Nov 2017 23:01:32 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39336) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eJX5L-0000Ka-Ff; Mon, 27 Nov 2017 23:01:27 -0500 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 D1D0C83F3E; Tue, 28 Nov 2017 04:01:25 +0000 (UTC) Received: from jason-ThinkPad-T450s.redhat.com (ovpn-12-142.pek2.redhat.com [10.72.12.142]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3DB445C888; Tue, 28 Nov 2017 04:01:14 +0000 (UTC) From: Jason Wang To: peter.maydell@linaro.org, qemu-devel@nongnu.org Date: Tue, 28 Nov 2017 12:01:09 +0800 Message-Id: <1511841669-14505-2-git-send-email-jasowang@redhat.com> In-Reply-To: <1511841669-14505-1-git-send-email-jasowang@redhat.com> References: <1511841669-14505-1-git-send-email-jasowang@redhat.com> 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 [10.5.110.27]); Tue, 28 Nov 2017 04:01:25 +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] virtio-net: don't touch virtqueue if vm is stopped 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: "Michael S . Tsirkin" , Jason Wang , qemu-stable@nongnu.org, Yuri Benditovich , Stefan Hajnoczi , Paolo Bonzini 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 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Guest state should not be touched if VM is stopped, unfortunately we didn't check running state and tried to drain tx queue unconditionally in virtio_net_set_status(). A crash was then noticed as a migration destination when user type quit after virtqueue state is loaded but before region cache is initialized. In this case, virtio_net_drop_tx_queue_data() tries to access the uninitialized region cache. Fix this by only dropping tx queue data when vm is running. Fixes: 283e2c2adcb80 ("net: virtio-net discards TX data after link down") Cc: Yuri Benditovich Cc: Paolo Bonzini Cc: Stefan Hajnoczi Cc: Michael S. Tsirkin Cc: qemu-stable@nongnu.org Reviewed-by: Stefan Hajnoczi Signed-off-by: Jason Wang --- hw/net/virtio-net.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index 150fd07..38674b0 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -288,7 +288,8 @@ static void virtio_net_set_status(struct VirtIODevice *= vdev, uint8_t status) qemu_bh_cancel(q->tx_bh); } if ((n->status & VIRTIO_NET_S_LINK_UP) =3D=3D 0 && - (queue_status & VIRTIO_CONFIG_S_DRIVER_OK)) { + (queue_status & VIRTIO_CONFIG_S_DRIVER_OK) && + vdev->vm_running) { /* if tx is waiting we are likely have some packets in tx = queue * and disabled notification */ q->tx_waiting =3D 0; --=20 2.7.4