[Qemu-devel] [PATCH 3/3] virtio-serial: Add a new virtserialport device for generic serial port support

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

This patch adds generic serial ports over the virtio serial bus.
These ports have a few more options that are not relevant for
virtio console ports: the ability to cache buffers that are
received for a port while it's disconnected, setting of limits
to the bytes that are cached so as to prevent OOM conditions,
etc.

Sample uses for such a device can be obtaining info from the
guest like the file systems used, apps installed, etc. for
offline usage and logged-in users, clipboard copy-paste, etc.
for online usage.

For requirements, use-cases, test cases and some history see

    http://www.linux-kvm.org/page/VMchannel_Requirements

Signed-off-by: Amit Shah <amit.shah@redhat.com>
---
 hw/virtio-console.c |   37 +++++++++++++++++++++++++++++++++++++
 1 files changed, 37 insertions(+), 0 deletions(-)

diff --git a/hw/virtio-console.c b/hw/virtio-console.c
index b2e4eb1..fc0c239 100644
--- a/hw/virtio-console.c
+++ b/hw/virtio-console.c
@@ -119,3 +119,40 @@ static void virtcon_register(void)
     virtio_serial_port_qdev_register(&virtcon_info);
 }
 device_init(virtcon_register)
+
+
+/* Generic Virtio Serial Ports */
+static int virtserial_port_initfn(VirtIOSerialDevice *dev)
+{
+    VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, &dev->qdev);
+    VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
+
+    port->info = dev->info;
+
+    if (vcon->chr) {
+        qemu_chr_add_handlers(vcon->chr, chr_can_read, chr_read, chr_event,
+                              vcon);
+    }
+    return 0;
+}
+
+static VirtIOSerialPortInfo virtserial_port_info = {
+    .qdev.name     = "virtserialport",
+    .qdev.size     = sizeof(VirtConsole),
+    .init          = virtserial_port_initfn,
+    .exit          = vcon_exitfn,
+    .have_data     = flush_buf,
+    .qdev.props = (Property[]) {
+        DEFINE_PROP_CHR("chardev", VirtConsole, chr),
+        DEFINE_PROP_STRING("name", VirtConsole, port.name),
+        DEFINE_PROP_INT32("cache_buffers", VirtConsole, port.cache_buffers, 1),
+        DEFINE_PROP_UINT64("byte_limit", VirtConsole, port.byte_limit, 0),
+        DEFINE_PROP_END_OF_LIST(),
+    },
+};
+
+static void virtserial_port_register(void)
+{
+    virtio_serial_port_qdev_register(&virtserial_port_info);
+}
+device_init(virtserial_port_register)
-- 
1.6.2.5