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authorAmit Shah <amit.shah@redhat.com>2010-04-27 18:04:10 +0530
committerAnthony Liguori <aliguori@us.ibm.com>2010-04-28 08:58:22 -0500
commita69c76008597ccdffae7a933686ab856ca85e87c (patch)
tree9bcdd27cc164eb4cff9a5d01eaaa97081dd7b6f8
parent1e4476aa03b70e78b0dbc21cebd6e9f9c6835067 (diff)
virtio-serial: Discard data that guest sends us when ports aren't connected
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 <amit.shah@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
-rw-r--r--hw/virtio-serial-bus.c69
1 files changed, 32 insertions, 37 deletions
diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c
index ad44127154..8d07152c08 100644
--- a/hw/virtio-serial-bus.c
+++ b/hw/virtio-serial-bus.c
@@ -111,6 +111,30 @@ static size_t write_to_port(VirtIOSerialPort *port,
return offset;
}
+static void flush_queued_data(VirtIOSerialPort *port, VirtQueue *vq,
+ VirtIODevice *vdev, bool discard)
+{
+ VirtQueueElement elem;
+
+ assert(port || discard);
+
+ 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(vdev, vq);
+}
+
static size_t send_control_msg(VirtIOSerialPort *port, void *buf, size_t len)
{
VirtQueueElement elem;
@@ -345,47 +369,18 @@ 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, vq, vdev, discard);
}
static void handle_input(VirtIODevice *vdev, VirtQueue *vq)