[Qemu-devel] [PATCH v3 3/4] virtio-serial-bus: separate out discard logic in a separate function

[Amit Shah <amit.shah@redhat.com>]

Instead of combining flush logic into the discard case and not discard
case, have one function doing discard case.  This will help later when
adding flow control logic to the do_flush_queued_data() function.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
---
 hw/virtio-serial-bus.c |   47 ++++++++++++++++++++++++++++++-----------------
 1 files changed, 30 insertions(+), 17 deletions(-)

diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c
index 74ba5ec..e8c2a16 100644
--- a/hw/virtio-serial-bus.c
+++ b/hw/virtio-serial-bus.c
@@ -113,39 +113,48 @@ static size_t write_to_port(VirtIOSerialPort *port,
     return offset;
 }
 
+static void discard_vq_data(VirtQueue *vq, VirtIODevice *vdev)
+{
+    VirtQueueElement elem;
+
+    while (virtqueue_pop(vq, &elem)) {
+        virtqueue_push(vq, &elem, 0);
+    }
+    virtio_notify(vdev, vq);
+}
+
 static void do_flush_queued_data(VirtIOSerialPort *port, VirtQueue *vq,
-                                 VirtIODevice *vdev, bool discard)
+                                 VirtIODevice *vdev)
 {
     VirtQueueElement elem;
 
-    assert(port || discard);
+    assert(port);
     assert(virtio_queue_ready(vq));
 
-    while ((discard || !port->throttled) && virtqueue_pop(vq, &elem)) {
+    while (!port->throttled && 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);
+        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);
 
-            port->info->have_data(port, buf, ret);
-            qemu_free(buf);
-        }
         virtqueue_push(vq, &elem, 0);
     }
     virtio_notify(vdev, vq);
 }
 
-static void flush_queued_data(VirtIOSerialPort *port, bool discard)
+static void flush_queued_data(VirtIOSerialPort *port)
 {
     assert(port);
 
     if (!virtio_queue_ready(port->ovq)) {
         return;
     }
-    do_flush_queued_data(port, port->ovq, &port->vser->vdev, discard);
+    do_flush_queued_data(port, port->ovq, &port->vser->vdev);
 }
 
 static size_t send_control_msg(VirtIOSerialPort *port, void *buf, size_t len)
@@ -204,7 +213,7 @@ int virtio_serial_close(VirtIOSerialPort *port)
      * consume, reset the throttling flag and discard the data.
      */
     port->throttled = false;
-    flush_queued_data(port, true);
+    discard_vq_data(port->ovq, &port->vser->vdev);
 
     send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
 
@@ -258,7 +267,7 @@ void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle)
         return;
     }
 
-    flush_queued_data(port, false);
+    flush_queued_data(port);
 }
 
 /* Guest wants to notify us of some event */
@@ -414,11 +423,15 @@ static void handle_output(VirtIODevice *vdev, VirtQueue *vq)
         discard = true;
     }
 
-    if (!discard && port->throttled) {
+    if (discard) {
+        discard_vq_data(vq, vdev);
+        return;
+    }
+    if (port->throttled) {
         return;
     }
 
-    do_flush_queued_data(port, vq, vdev, discard);
+    do_flush_queued_data(port, vq, vdev);
 }
 
 static void handle_input(VirtIODevice *vdev, VirtQueue *vq)
@@ -634,7 +647,7 @@ static void remove_port(VirtIOSerial *vser, uint32_t port_id)
 
     port = find_port_by_id(vser, port_id);
     /* Flush out any unconsumed buffers first */
-    flush_queued_data(port, true);
+    discard_vq_data(port->ovq, &port->vser->vdev);
 
     send_control_event(port, VIRTIO_CONSOLE_PORT_REMOVE, 1);
 }
-- 
1.7.3.4