From patchwork Wed Apr 14 05:28:36 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Amit Shah X-Patchwork-Id: 50113 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 8F4A7B7D28 for ; Wed, 14 Apr 2010 16:16:48 +1000 (EST) Received: from localhost ([127.0.0.1]:38733 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1O1vu1-0000sp-Gk for incoming@patchwork.ozlabs.org; Wed, 14 Apr 2010 02:16:45 -0400 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1O1vCQ-0002br-NO for qemu-devel@nongnu.org; Wed, 14 Apr 2010 01:31:42 -0400 Received: from [140.186.70.92] (port=49157 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1O1vCP-0002bP-7r for qemu-devel@nongnu.org; Wed, 14 Apr 2010 01:31:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1O1vCN-000663-Le for qemu-devel@nongnu.org; Wed, 14 Apr 2010 01:31:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:17897) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1O1vCN-00065o-1W for qemu-devel@nongnu.org; Wed, 14 Apr 2010 01:31:39 -0400 Received: from int-mx08.intmail.prod.int.phx2.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o3E5VWR6017878 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 14 Apr 2010 01:31:32 -0400 Received: from localhost (vpn-236-230.phx2.redhat.com [10.3.236.230]) by int-mx08.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o3E5VSQk001619; Wed, 14 Apr 2010 01:31:29 -0400 From: Amit Shah To: Anthony Liguori Date: Wed, 14 Apr 2010 10:58:36 +0530 Message-Id: <1271222917-7803-17-git-send-email-amit.shah@redhat.com> In-Reply-To: <1271222917-7803-16-git-send-email-amit.shah@redhat.com> References: <1271222917-7803-1-git-send-email-amit.shah@redhat.com> <1271222917-7803-2-git-send-email-amit.shah@redhat.com> <1271222917-7803-3-git-send-email-amit.shah@redhat.com> <1271222917-7803-4-git-send-email-amit.shah@redhat.com> <1271222917-7803-5-git-send-email-amit.shah@redhat.com> <1271222917-7803-6-git-send-email-amit.shah@redhat.com> <1271222917-7803-7-git-send-email-amit.shah@redhat.com> <1271222917-7803-8-git-send-email-amit.shah@redhat.com> <1271222917-7803-9-git-send-email-amit.shah@redhat.com> <1271222917-7803-10-git-send-email-amit.shah@redhat.com> <1271222917-7803-11-git-send-email-amit.shah@redhat.com> <1271222917-7803-12-git-send-email-amit.shah@redhat.com> <1271222917-7803-13-git-send-email-amit.shah@redhat.com> <1271222917-7803-14-git-send-email-amit.shah@redhat.com> <1271222917-7803-15-git-send-email-amit.shah@redhat.com> <1271222917-7803-16-git-send-email-amit.shah@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.21 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. Cc: qemu list , Amit Shah , Gerd Hoffmann , Juan Quintela Subject: [Qemu-devel] [PATCH v5 16/17] virtio-serial: Discard data that guest sends us when ports aren't connected X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Before the earlier patch, we relied on incorrect virtio api usage to signal to the guest that a particular buffer wasn't consumed by the host. After fixing that, we now just discard the data the guest sends us while a host port is disconnected or doesn't have a handler registered for consuming data. This commit really doesn't change anything from the current behaviour, just makes the code slightly better by spinning off data handling to ports in another function. Signed-off-by: Amit Shah --- hw/virtio-serial-bus.c | 68 ++++++++++++++++++++++-------------------------- 1 files changed, 31 insertions(+), 37 deletions(-) diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c index ad44127..0166780 100644 --- a/hw/virtio-serial-bus.c +++ b/hw/virtio-serial-bus.c @@ -111,6 +111,29 @@ static size_t write_to_port(VirtIOSerialPort *port, return offset; } +static void flush_queued_data(VirtIOSerialPort *port, bool discard) +{ + VirtQueue *vq; + VirtQueueElement elem; + + vq = port->ovq; + while (virtqueue_pop(vq, &elem)) { + uint8_t *buf; + size_t ret, buf_size; + + if (!discard) { + buf_size = iov_size(elem.out_sg, elem.out_num); + buf = qemu_malloc(buf_size); + ret = iov_to_buf(elem.out_sg, elem.out_num, buf, 0, buf_size); + + port->info->have_data(port, buf, ret); + qemu_free(buf); + } + virtqueue_push(vq, &elem, 0); + } + virtio_notify(&port->vser->vdev, vq); +} + static size_t send_control_msg(VirtIOSerialPort *port, void *buf, size_t len) { VirtQueueElement elem; @@ -345,47 +368,18 @@ static void control_out(VirtIODevice *vdev, VirtQueue *vq) static void handle_output(VirtIODevice *vdev, VirtQueue *vq) { VirtIOSerial *vser; - VirtQueueElement elem; + VirtIOSerialPort *port; + bool discard; vser = DO_UPCAST(VirtIOSerial, vdev, vdev); + port = find_port_by_vq(vser, vq); - while (virtqueue_pop(vq, &elem)) { - VirtIOSerialPort *port; - uint8_t *buf; - size_t ret, buf_size; - - port = find_port_by_vq(vser, vq); - if (!port) { - ret = 0; - goto next_buf; - } - - if (!port->host_connected) { - ret = 0; - goto next_buf; - } - - /* - * A port may not have any handler registered for consuming the - * data that the guest sends or it may not have a chardev associated - * with it. Just ignore the data in that case. - */ - if (!port->info->have_data) { - ret = 0; - goto next_buf; - } - - buf_size = iov_size(elem.out_sg, elem.out_num); - buf = qemu_malloc(buf_size); - ret = iov_to_buf(elem.out_sg, elem.out_num, buf, 0, buf_size); - - port->info->have_data(port, buf, ret); - qemu_free(buf); - - next_buf: - virtqueue_push(vq, &elem, 0); + discard = false; + if (!port || !port->host_connected || !port->info->have_data) { + discard = true; } - virtio_notify(vdev, vq); + + flush_queued_data(port, discard); } static void handle_input(VirtIODevice *vdev, VirtQueue *vq)