Re: [Qemu-devel] [PATCH 3/8] virtio-serial-bus: Maintain guest and host port open/close state

[Anthony Liguori]

On 12/23/2009 01:52 PM, Amit Shah wrote:
Via control channel messages, the guest can tell us whether a port got
opened or closed. Similarly, we can also indicate to the guest of host
port open/close events.
Signed-off-by: Amit Shah<amit.s...@redhat.com>
---
  hw/virtio-serial-bus.c |   73 ++++++++++++++++++++++++++++++++++++++++++++++++
  hw/virtio-serial.c     |    6 ++++
  hw/virtio-serial.h     |    6 ++++
  3 files changed, 85 insertions(+), 0 deletions(-)


@@ -347,6 +378,8 @@ static void set_config(VirtIODevice *vdev, const uint8_t 
*config_data)
  static void virtio_serial_save(QEMUFile *f, void *opaque)
  {
      VirtIOSerial *s = opaque;
+    VirtIOSerialPort *port;
+    uint32_t nr_active_ports;

      /* The virtio device */
      virtio_save(&s->vdev, f);
@@ -357,11 +390,35 @@ static void virtio_serial_save(QEMUFile *f, void *opaque)

      /* Items in struct VirtIOSerial */
      qemu_put_be32s(f,&s->guest_features);
+
+    /* Do this because we might have hot-unplugged some ports */
+    nr_active_ports = 0;
+    QTAILQ_FOREACH(port,&s->ports, next)
+        nr_active_ports++;
+
+    qemu_put_be32s(f,&nr_active_ports);
+
+    /*
+     * Items in struct VirtIOSerialPort.
+     */
+    QTAILQ_FOREACH(port,&s->ports, next) {
+        /*
+         * We put the port number because we may not have an active
+         * port at id 0 that's reserved for a console port, or in case
+         * of ports that might have gotten unplugged
+         */
+        qemu_put_be32s(f,&port->id);
+        qemu_put_byte(f, port->guest_connected);
+
+    }
  }


I imagine this sort of thing is going to give Juan quite a head-ache 
when it comes time to VMState conversion.

Are there not separate qdev devices for each port?  Can't the state be 
stored in that?

Regards,

Anthony Liguori