2 * Virtio Serial / Console Support
4 * Copyright IBM, Corp. 2008
5 * Copyright Red Hat, Inc. 2009, 2010
8 * Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
9 * Amit Shah <amit.shah@redhat.com>
11 * This work is licensed under the terms of the GNU GPL, version 2. See
12 * the COPYING file in the top-level directory.
15 #ifndef _QEMU_VIRTIO_SERIAL_H
16 #define _QEMU_VIRTIO_SERIAL_H
19 #include "hw/virtio.h"
21 /* == Interface shared between the guest kernel and qemu == */
23 /* The Virtio ID for virtio console / serial ports */
24 #define VIRTIO_ID_CONSOLE 3
26 /* Features supported */
27 #define VIRTIO_CONSOLE_F_MULTIPORT 1
29 #define VIRTIO_CONSOLE_BAD_ID (~(uint32_t)0)
31 struct virtio_console_config
{
33 * These two fields are used by VIRTIO_CONSOLE_F_SIZE which
34 * isn't implemented here yet
39 uint32_t max_nr_ports
;
42 struct virtio_console_control
{
43 uint32_t id
; /* Port number */
44 uint16_t event
; /* The kind of control event (see below) */
45 uint16_t value
; /* Extra information for the key */
48 struct virtio_serial_conf
{
49 /* Max. number of ports we can have for a virtio-serial device */
50 uint32_t max_virtserial_ports
;
53 /* Some events for the internal messages (control packets) */
54 #define VIRTIO_CONSOLE_DEVICE_READY 0
55 #define VIRTIO_CONSOLE_PORT_ADD 1
56 #define VIRTIO_CONSOLE_PORT_REMOVE 2
57 #define VIRTIO_CONSOLE_PORT_READY 3
58 #define VIRTIO_CONSOLE_CONSOLE_PORT 4
59 #define VIRTIO_CONSOLE_RESIZE 5
60 #define VIRTIO_CONSOLE_PORT_OPEN 6
61 #define VIRTIO_CONSOLE_PORT_NAME 7
63 /* == In-qemu interface == */
65 #define TYPE_VIRTIO_SERIAL_PORT "virtio-serial-port"
66 #define VIRTIO_SERIAL_PORT(obj) \
67 OBJECT_CHECK(VirtIOSerialPort, (obj), TYPE_VIRTIO_SERIAL_PORT)
68 #define VIRTIO_SERIAL_PORT_CLASS(klass) \
69 OBJECT_CLASS_CHECK(VirtIOSerialPortClass, (klass), TYPE_VIRTIO_SERIAL_PORT)
70 #define VIRTIO_SERIAL_PORT_GET_CLASS(obj) \
71 OBJECT_GET_CLASS(VirtIOSerialPortClass, (obj), TYPE_VIRTIO_SERIAL_PORT)
73 typedef struct VirtIOSerial VirtIOSerial
;
74 typedef struct VirtIOSerialBus VirtIOSerialBus
;
75 typedef struct VirtIOSerialPort VirtIOSerialPort
;
77 typedef struct VirtIOSerialPortClass
{
78 DeviceClass parent_class
;
80 /* Is this a device that binds with hvc in the guest? */
84 * The per-port (or per-app) init function that's called when a
85 * new device is found on the bus.
87 int (*init
)(VirtIOSerialPort
*port
);
89 * Per-port exit function that's called when a port gets
90 * hot-unplugged or removed.
92 int (*exit
)(VirtIOSerialPort
*port
);
94 /* Callbacks for guest events */
95 /* Guest opened device. */
96 void (*guest_open
)(VirtIOSerialPort
*port
);
97 /* Guest closed device. */
98 void (*guest_close
)(VirtIOSerialPort
*port
);
100 /* Guest is now ready to accept data (virtqueues set up). */
101 void (*guest_ready
)(VirtIOSerialPort
*port
);
104 * Guest wrote some data to the port. This data is handed over to
105 * the app via this callback. The app can return a size less than
106 * 'len'. In this case, throttling will be enabled for this port.
108 ssize_t (*have_data
)(VirtIOSerialPort
*port
, const uint8_t *buf
,
110 } VirtIOSerialPortClass
;
113 * This is the state that's shared between all the ports. Some of the
114 * state is configurable via command-line options. Some of it can be
115 * set by individual devices in their initfn routines. Some of the
116 * state is set by the generic qdev device init routine.
118 struct VirtIOSerialPort
{
121 QTAILQ_ENTRY(VirtIOSerialPort
) next
;
124 * This field gives us the virtio device as well as the qdev bus
125 * that we are associated with
129 VirtQueue
*ivq
, *ovq
;
132 * This name is sent to the guest and exported via sysfs.
133 * The guest could create symlinks based on this information.
134 * The name is in the reverse fqdn format, like org.qemu.console.0
139 * This id helps identify ports between the guest and the host.
140 * The guest sends a "header" with this id with each data packet
141 * that it sends and the host can then find out which associated
142 * device to send out this data to
147 * This is the elem that we pop from the virtqueue. A slow
148 * backend that consumes guest data (e.g. the file backend for
149 * qemu chardevs) can cause the guest to block till all the output
150 * is flushed. This isn't desired, so we keep a note of the last
151 * element popped and continue consuming it once the backend
152 * becomes writable again.
154 VirtQueueElement elem
;
157 * The index and the offset into the iov buffer that was popped in
164 * When unthrottling we use a bottom-half to call flush_queued_data.
168 /* Is the corresponding guest device open? */
169 bool guest_connected
;
170 /* Is this device open for IO on the host? */
172 /* Do apps not want to receive data? */
176 /* Interface to the virtio-serial bus */
179 * Open a connection to the port
180 * Returns 0 on success (always).
182 int virtio_serial_open(VirtIOSerialPort
*port
);
185 * Close the connection to the port
186 * Returns 0 on success (always).
188 int virtio_serial_close(VirtIOSerialPort
*port
);
193 ssize_t
virtio_serial_write(VirtIOSerialPort
*port
, const uint8_t *buf
,
197 * Query whether a guest is ready to receive data.
199 size_t virtio_serial_guest_ready(VirtIOSerialPort
*port
);
202 * Flow control: Ports can signal to the virtio-serial core to stop
203 * sending data or re-start sending data, depending on the 'throttle'
206 void virtio_serial_throttle_port(VirtIOSerialPort
*port
, bool throttle
);