qemu/hw/virtio-console.c
Amit Shah f9a90f189c virtio-console: Keep chardev open for other users after hot-unplug
After a hot-unplug operation, the previous behaviour was to close the
chardev.  That meant the chardev couldn't be re-used.  Also, since
chardev hot-plug isn't possible so far, this means virtio-console
hot-plug isn't feasible as well.

With this change, the chardev is kept around.  A new virtio-console
channel can then be hot-plugged with the same chardev and things will
continue to work.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
2011-03-21 16:56:55 +05:30

149 lines
3.9 KiB
C

/*
* Virtio Console and Generic Serial Port Devices
*
* Copyright Red Hat, Inc. 2009, 2010
*
* Authors:
* Amit Shah <amit.shah@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*/
#include "qemu-char.h"
#include "qemu-error.h"
#include "virtio-serial.h"
typedef struct VirtConsole {
VirtIOSerialPort port;
CharDriverState *chr;
} VirtConsole;
/* Callback function that's called when the guest sends us data */
static ssize_t flush_buf(VirtIOSerialPort *port, const uint8_t *buf, size_t len)
{
VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
return qemu_chr_write(vcon->chr, buf, len);
}
/* Readiness of the guest to accept data on a port */
static int chr_can_read(void *opaque)
{
VirtConsole *vcon = opaque;
return virtio_serial_guest_ready(&vcon->port);
}
/* Send data from a char device over to the guest */
static void chr_read(void *opaque, const uint8_t *buf, int size)
{
VirtConsole *vcon = opaque;
virtio_serial_write(&vcon->port, buf, size);
}
static void chr_event(void *opaque, int event)
{
VirtConsole *vcon = opaque;
switch (event) {
case CHR_EVENT_OPENED:
virtio_serial_open(&vcon->port);
break;
case CHR_EVENT_CLOSED:
virtio_serial_close(&vcon->port);
break;
}
}
static int generic_port_init(VirtConsole *vcon, VirtIOSerialPort *port)
{
if (vcon->chr) {
qemu_chr_add_handlers(vcon->chr, chr_can_read, chr_read, chr_event,
vcon);
vcon->port.info->have_data = flush_buf;
}
return 0;
}
/* Virtio Console Ports */
static int virtconsole_initfn(VirtIOSerialPort *port)
{
VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
port->is_console = true;
return generic_port_init(vcon, port);
}
static int virtconsole_exitfn(VirtIOSerialPort *port)
{
VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
if (vcon->chr) {
/*
* Instead of closing the chardev, free it so it can be used
* for other purposes.
*/
qemu_chr_add_handlers(vcon->chr, NULL, NULL, NULL, NULL);
}
return 0;
}
static VirtIOSerialPortInfo virtconsole_info = {
.qdev.name = "virtconsole",
.qdev.size = sizeof(VirtConsole),
.init = virtconsole_initfn,
.exit = virtconsole_exitfn,
.qdev.props = (Property[]) {
DEFINE_PROP_UINT8("is_console", VirtConsole, port.is_console, 1),
DEFINE_PROP_UINT32("nr", VirtConsole, port.id, VIRTIO_CONSOLE_BAD_ID),
DEFINE_PROP_CHR("chardev", VirtConsole, chr),
DEFINE_PROP_STRING("name", VirtConsole, port.name),
DEFINE_PROP_END_OF_LIST(),
},
};
static void virtconsole_register(void)
{
virtio_serial_port_qdev_register(&virtconsole_info);
}
device_init(virtconsole_register)
/* Generic Virtio Serial Ports */
static int virtserialport_initfn(VirtIOSerialPort *port)
{
VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
if (port->id == 0) {
/*
* Disallow a generic port at id 0, that's reserved for
* console ports.
*/
error_report("Port number 0 on virtio-serial devices reserved for virtconsole devices for backward compatibility.");
return -1;
}
return generic_port_init(vcon, port);
}
static VirtIOSerialPortInfo virtserialport_info = {
.qdev.name = "virtserialport",
.qdev.size = sizeof(VirtConsole),
.init = virtserialport_initfn,
.exit = virtconsole_exitfn,
.qdev.props = (Property[]) {
DEFINE_PROP_UINT32("nr", VirtConsole, port.id, VIRTIO_CONSOLE_BAD_ID),
DEFINE_PROP_CHR("chardev", VirtConsole, chr),
DEFINE_PROP_STRING("name", VirtConsole, port.name),
DEFINE_PROP_END_OF_LIST(),
},
};
static void virtserialport_register(void)
{
virtio_serial_port_qdev_register(&virtserialport_info);
}
device_init(virtserialport_register)