From ed4daf8c7722562ec05e83ec98a4d4d8adf20f7f Mon Sep 17 00:00:00 2001

From: Amit Shah <amit.shah@redhat.com>

Date: Wed, 20 Jan 2010 00:36:54 +0530

Subject: [PATCH 4/9] virtio-serial-bus: Add a port 'name' property for port discovery in guests

The port 'id' or number is internal state between the guest kernel and

our bus implementation. This is invocation-dependent and isn't part of

the guest-host ABI.

To correcly enumerate and map ports between the host and the guest, the

'name' property is used.

Example:

    -device virtserialport,name=org.qemu.port.0

This invocation will get us a char device in the guest at:

    /dev/virtio-ports/org.qemu.port.0

which can be a symlink to

    /dev/vport0p3

This 'name' property is exposed by the guest kernel in a sysfs

attribute:

    /sys/kernel/virtio-ports/vport0p3/name

A simple udev script can pick up this name and create the symlink

mentioned above.

Signed-off-by: Amit Shah <amit.shah@redhat.com>

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

---

 hw/virtio-serial-bus.c |   17 +++++++++++++++++

 hw/virtio-serial.c     |    1 +

 hw/virtio-serial.h     |    8 ++++++++

 3 files changed, 26 insertions(+), 0 deletions(-)

diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c

index 9af21df..6d69c56 100644

--- a/hw/virtio-serial-bus.c

+++ b/hw/virtio-serial-bus.c

@@ -204,6 +204,8 @@ static void handle_control_message(VirtIOSerial *vser, void *buf)

 {

     struct VirtIOSerialPort *port;

     struct virtio_console_control cpkt, *gcpkt;

+    uint8_t *buffer;

+    size_t buffer_len;

     gcpkt = buf;

     port = find_port_by_id(vser, ldl_p(&gcpkt->id));

@@ -226,6 +228,21 @@ static void handle_control_message(VirtIOSerial *vser, void *buf)

             send_control_event(port, VIRTIO_CONSOLE_CONSOLE_PORT, 1);

         }

+        if (port->name) {

+            stw_p(&cpkt.event, VIRTIO_CONSOLE_PORT_NAME);

+            stw_p(&cpkt.value, 1);

+

+            buffer_len = sizeof(cpkt) + strlen(port->name) + 1;

+            buffer = qemu_malloc(buffer_len);

+

+            memcpy(buffer, &cpkt, sizeof(cpkt));

+            memcpy(buffer + sizeof(cpkt), port->name, strlen(port->name));

+            buffer[buffer_len - 1] = 0;

+

+            send_control_msg(port, buffer, buffer_len);

+            qemu_free(buffer);

+        }

+

         if (port->host_connected) {

             send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN, 1);

         }

diff --git a/hw/virtio-serial.c b/hw/virtio-serial.c

index 1dc031e..9c2c93c 100644

--- a/hw/virtio-serial.c

+++ b/hw/virtio-serial.c

@@ -100,6 +100,7 @@ static VirtIOSerialPortInfo virtconsole_info = {

     .qdev.props = (Property[]) {

         DEFINE_PROP_UINT8("is_console", VirtConsole, port.is_console, 1),

         DEFINE_PROP_CHR("chardev", VirtConsole, chr),

+        DEFINE_PROP_STRING("name", VirtConsole, port.name),

         DEFINE_PROP_END_OF_LIST(),

     },

 };

diff --git a/hw/virtio-serial.h b/hw/virtio-serial.h

index d9c7acb..28ea7da 100644

--- a/hw/virtio-serial.h

+++ b/hw/virtio-serial.h

@@ -50,6 +50,7 @@ struct virtio_console_control {

 #define VIRTIO_CONSOLE_CONSOLE_PORT	1

 #define VIRTIO_CONSOLE_RESIZE		2

 #define VIRTIO_CONSOLE_PORT_OPEN	3

+#define VIRTIO_CONSOLE_PORT_NAME	4

 /* == In-qemu interface == */

@@ -84,6 +85,13 @@ struct VirtIOSerialPort {

     VirtQueue *ivq, *ovq;

     /*

+     * This name is sent to the guest and exported via sysfs.

+     * The guest could create symlinks based on this information.

+     * The name is in the reverse fqdn format, like org.qemu.console.0

+     */

+    char *name;

+

+    /*

      * This id helps identify ports between the guest and the host.

      * The guest sends a "header" with this id with each data packet

      * that it sends and the host can then find out which associated

-- 

1.6.2.5