qemu/hw/virtio-console.c

169 lines
4.5 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 "trace.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);
ssize_t ret;
ret = qemu_chr_fe_write(vcon->chr, buf, len);
trace_virtio_console_flush_buf(port->id, len, ret);
if (ret < 0) {
/*
* Ideally we'd get a better error code than just -1, but
* that's what the chardev interface gives us right now. If
* we had a finer-grained message, like -EPIPE, we could close
* this connection. Absent such error messages, the most we
* can do is to return 0 here.
*
* This will prevent stray -1 values to go to
* virtio-serial-bus.c and cause abort()s in
* do_flush_queued_data().
*/
ret = 0;
}
return ret;
}
/* Callback function that's called when the guest opens the port */
static void guest_open(VirtIOSerialPort *port)
{
VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
qemu_chr_fe_open(vcon->chr);
}
/* Callback function that's called when the guest closes the port */
static void guest_close(VirtIOSerialPort *port)
{
VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
qemu_chr_fe_close(vcon->chr);
}
/* 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;
trace_virtio_console_chr_read(vcon->port.id, size);
virtio_serial_write(&vcon->port, buf, size);
}
static void chr_event(void *opaque, int event)
{
VirtConsole *vcon = opaque;
trace_virtio_console_chr_event(vcon->port.id, event);
switch (event) {
case CHR_EVENT_OPENED:
virtio_serial_open(&vcon->port);
break;
case CHR_EVENT_CLOSED:
virtio_serial_close(&vcon->port);
break;
}
}
static int virtconsole_initfn(VirtIOSerialPort *port)
{
VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
VirtIOSerialPortInfo *info = DO_UPCAST(VirtIOSerialPortInfo, qdev,
vcon->port.dev.info);
if (port->id == 0 && !info->is_console) {
error_report("Port number 0 on virtio-serial devices reserved for virtconsole devices for backward compatibility.");
return -1;
}
if (vcon->chr) {
qemu_chr_add_handlers(vcon->chr, chr_can_read, chr_read, chr_event,
vcon);
info->have_data = flush_buf;
info->guest_open = guest_open;
info->guest_close = guest_close;
}
return 0;
}
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),
.is_console = true,
.init = virtconsole_initfn,
.exit = virtconsole_exitfn,
.qdev.props = (Property[]) {
DEFINE_PROP_CHR("chardev", VirtConsole, chr),
DEFINE_PROP_END_OF_LIST(),
},
};
static void virtconsole_register(void)
{
virtio_serial_port_qdev_register(&virtconsole_info);
}
device_init(virtconsole_register)
static VirtIOSerialPortInfo virtserialport_info = {
.qdev.name = "virtserialport",
.qdev.size = sizeof(VirtConsole),
.init = virtconsole_initfn,
.exit = virtconsole_exitfn,
.qdev.props = (Property[]) {
DEFINE_PROP_CHR("chardev", VirtConsole, chr),
DEFINE_PROP_END_OF_LIST(),
},
};
static void virtserialport_register(void)
{
virtio_serial_port_qdev_register(&virtserialport_info);
}
device_init(virtserialport_register)