From patchwork Thu Jul 1 09:28:16 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [1/2] virtio-serial: Check if virtio queue is ready before consuming data From: Amit Shah X-Patchwork-Id: 57495 Message-Id: <1c5b20f693ebc3882d01d8f2f9e807878251cd42.1277976486.git.amit.shah@redhat.com> To: qemu list Cc: Amit Shah Date: Thu, 1 Jul 2010 14:58:16 +0530 If a virtio-serial port is removed before the guest comes up and initialises the virtqueues, qemu exits with the message Guest moved used index from 0 to 61440 This happens because we try to clear any pending buffers from the virtqueue. Ensure the virtqueue is initialised before calling any virtqueue operations. Signed-off-by: Amit Shah --- hw/virtio-serial-bus.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c index 7f9d28f..b89daa6 100644 --- a/hw/virtio-serial-bus.c +++ b/hw/virtio-serial-bus.c @@ -139,6 +139,9 @@ static void flush_queued_data(VirtIOSerialPort *port, bool discard) { assert(port); + if (!virtio_queue_ready(port->ovq)) { + return; + } do_flush_queued_data(port, port->ovq, &port->vser->vdev, discard); }