hw/virtio-serial.h

   1 /*
   2  * Virtio Serial / Console Support
   3  *
   4  * Copyright IBM, Corp. 2008
   5  * Copyright Red Hat, Inc. 2009, 2010
   6  *
   7  * Authors:
   8  *  Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
   9  *  Amit Shah <amit.shah@redhat.com>
  10  *
  11  * This work is licensed under the terms of the GNU GPL, version 2.  See
  12  * the COPYING file in the top-level directory.
  13  *
  14  */
  15 #ifndef _QEMU_VIRTIO_SERIAL_H
  16 #define _QEMU_VIRTIO_SERIAL_H
  17
  18 #include <stdbool.h>
  19 #include "qdev.h"
  20 #include "virtio.h"
  21
  22 /* == Interface shared between the guest kernel and qemu == */
  23
  24 /* The Virtio ID for virtio console / serial ports */
  25 #define VIRTIO_ID_CONSOLE               3
  26
  27 /* Features supported */
  28 #define VIRTIO_CONSOLE_F_MULTIPORT      1
  29
  30 #define VIRTIO_CONSOLE_BAD_ID           (~(uint32_t)0)
  31
  32 struct virtio_console_config {
  33     /*
  34      * These two fields are used by VIRTIO_CONSOLE_F_SIZE which
  35      * isn't implemented here yet
  36      */
  37     uint16_t cols;
  38     uint16_t rows;
  39
  40     uint32_t max_nr_ports;
  41 } __attribute__((packed));
  42
  43 struct virtio_console_control {
  44     uint32_t id;                /* Port number */
  45     uint16_t event;             /* The kind of control event (see below) */
  46     uint16_t value;             /* Extra information for the key */
  47 };
  48
  49 /* Some events for the internal messages (control packets) */
  50 #define VIRTIO_CONSOLE_DEVICE_READY     0
  51 #define VIRTIO_CONSOLE_PORT_ADD         1
  52 #define VIRTIO_CONSOLE_PORT_REMOVE      2
  53 #define VIRTIO_CONSOLE_PORT_READY       3
  54 #define VIRTIO_CONSOLE_CONSOLE_PORT     4
  55 #define VIRTIO_CONSOLE_RESIZE           5
  56 #define VIRTIO_CONSOLE_PORT_OPEN        6
  57 #define VIRTIO_CONSOLE_PORT_NAME        7
  58
  59 /* == In-qemu interface == */
  60
  61 typedef struct VirtIOSerial VirtIOSerial;
  62 typedef struct VirtIOSerialBus VirtIOSerialBus;
  63 typedef struct VirtIOSerialPort VirtIOSerialPort;
  64 typedef struct VirtIOSerialPortInfo VirtIOSerialPortInfo;
  65
  66 typedef struct VirtIOSerialDevice {
  67     DeviceState qdev;
  68     VirtIOSerialPortInfo *info;
  69 } VirtIOSerialDevice;
  70
  71 /*
  72  * This is the state that's shared between all the ports.  Some of the
  73  * state is configurable via command-line options. Some of it can be
  74  * set by individual devices in their initfn routines. Some of the
  75  * state is set by the generic qdev device init routine.
  76  */
  77 struct VirtIOSerialPort {
  78     DeviceState dev;
  79     VirtIOSerialPortInfo *info;
  80
  81     QTAILQ_ENTRY(VirtIOSerialPort) next;
  82
  83     /*
  84      * This field gives us the virtio device as well as the qdev bus
  85      * that we are associated with
  86      */
  87     VirtIOSerial *vser;
  88
  89     VirtQueue *ivq, *ovq;
  90
  91     /*
  92      * This name is sent to the guest and exported via sysfs.
  93      * The guest could create symlinks based on this information.
  94      * The name is in the reverse fqdn format, like org.qemu.console.0
  95      */
  96     char *name;
  97
  98     /*
  99      * This id helps identify ports between the guest and the host.
 100      * The guest sends a "header" with this id with each data packet
 101      * that it sends and the host can then find out which associated
 102      * device to send out this data to
 103      */
 104     uint32_t id;
 105
 106     /* Identify if this is a port that binds with hvc in the guest */
 107     uint8_t is_console;
 108
 109     /* Is the corresponding guest device open? */
 110     bool guest_connected;
 111     /* Is this device open for IO on the host? */
 112     bool host_connected;
 113     /* Do apps not want to receive data? */
 114     bool throttled;
 115 };
 116
 117 struct VirtIOSerialPortInfo {
 118     DeviceInfo qdev;
 119     /*
 120      * The per-port (or per-app) init function that's called when a
 121      * new device is found on the bus.
 122      */
 123     int (*init)(VirtIOSerialDevice *dev);
 124     /*
 125      * Per-port exit function that's called when a port gets
 126      * hot-unplugged or removed.
 127      */
 128     int (*exit)(VirtIOSerialDevice *dev);
 129
 130     /* Callbacks for guest events */
 131         /* Guest opened device. */
 132     void (*guest_open)(VirtIOSerialPort *port);
 133         /* Guest closed device. */
 134     void (*guest_close)(VirtIOSerialPort *port);
 135
 136         /* Guest is now ready to accept data (virtqueues set up). */
 137     void (*guest_ready)(VirtIOSerialPort *port);
 138
 139     /*
 140      * Guest wrote some data to the port. This data is handed over to
 141      * the app via this callback.  The app is supposed to consume all
 142      * the data that is presented to it.
 143      */
 144     void (*have_data)(VirtIOSerialPort *port, const uint8_t *buf, size_t len);
 145 };
 146
 147 /* Interface to the virtio-serial bus */
 148
 149 /*
 150  * Individual ports/apps should call this function to register the port
 151  * with the virtio-serial bus
 152  */
 153 void virtio_serial_port_qdev_register(VirtIOSerialPortInfo *info);
 154
 155 /*
 156  * Open a connection to the port
 157  *   Returns 0 on success (always).
 158  */
 159 int virtio_serial_open(VirtIOSerialPort *port);
 160
 161 /*
 162  * Close the connection to the port
 163  *   Returns 0 on success (always).
 164  */
 165 int virtio_serial_close(VirtIOSerialPort *port);
 166
 167 /*
 168  * Send data to Guest
 169  */
 170 ssize_t virtio_serial_write(VirtIOSerialPort *port, const uint8_t *buf,
 171                             size_t size);
 172
 173 /*
 174  * Query whether a guest is ready to receive data.
 175  */
 176 size_t virtio_serial_guest_ready(VirtIOSerialPort *port);
 177
 178 /*
 179  * Flow control: Ports can signal to the virtio-serial core to stop
 180  * sending data or re-start sending data, depending on the 'throttle'
 181  * value here.
 182  */
 183 void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle);
 184
 185 #endif