hw/virtio-serial.h

   1 /*
   2  * Virtio Serial / Console Support
   3  *
   4  * Copyright IBM, Corp. 2008
   5  * Copyright Red Hat, Inc. 2009
   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 struct virtio_console_config {
  31     /*
  32      * These two fields are used by VIRTIO_CONSOLE_F_SIZE which
  33      * isn't implemented here yet
  34      */
  35     uint16_t cols;
  36     uint16_t rows;
  37
  38     uint32_t max_nr_ports;
  39     uint32_t nr_ports;
  40 } __attribute__((packed));
  41
  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 */
  46 };
  47
  48 /* Some events for the internal messages (control packets) */
  49 #define VIRTIO_CONSOLE_PORT_READY       0
  50 #define VIRTIO_CONSOLE_CONSOLE_PORT     1
  51 #define VIRTIO_CONSOLE_RESIZE           2
  52
  53 /* == In-qemu interface == */
  54
  55 typedef struct VirtIOSerial VirtIOSerial;
  56 typedef struct VirtIOSerialBus VirtIOSerialBus;
  57 typedef struct VirtIOSerialPort VirtIOSerialPort;
  58 typedef struct VirtIOSerialPortInfo VirtIOSerialPortInfo;
  59
  60 typedef struct VirtIOSerialDevice {
  61     DeviceState qdev;
  62     VirtIOSerialPortInfo *info;
  63 } VirtIOSerialDevice;
  64
  65 /*
  66  * This is the state that's shared between all the ports.  Some of the
  67  * state is configurable via command-line options. Some of it can be
  68  * set by individual devices in their initfn routines. Some of the
  69  * state is set by the generic qdev device init routine.
  70  */
  71 struct VirtIOSerialPort {
  72     DeviceState dev;
  73     VirtIOSerialPortInfo *info;
  74
  75     QTAILQ_ENTRY(VirtIOSerialPort) next;
  76
  77     /*
  78      * This field gives us the virtio device as well as the qdev bus
  79      * that we are associated with
  80      */
  81     VirtIOSerial *vser;
  82
  83     VirtQueue *ivq, *ovq;
  84
  85     /*
  86      * This id helps identify ports between the guest and the host.
  87      * The guest sends a "header" with this id with each data packet
  88      * that it sends and the host can then find out which associated
  89      * device to send out this data to
  90      */
  91     uint32_t id;
  92
  93     /* Identify if this is a port that binds with hvc in the guest */
  94     uint8_t is_console;
  95 };
  96
  97 struct VirtIOSerialPortInfo {
  98     DeviceInfo qdev;
  99     /*
 100      * The per-port (or per-app) init function that's called when a
 101      * new device is found on the bus.
 102      */
 103     int (*init)(VirtIOSerialDevice *dev);
 104     /*
 105      * Per-port exit function that's called when a port gets
 106      * hot-unplugged or removed.
 107      */
 108     int (*exit)(VirtIOSerialDevice *dev);
 109
 110     /* Callbacks for guest events */
 111         /* Guest opened device. */
 112     void (*guest_open)(VirtIOSerialPort *port);
 113         /* Guest closed device. */
 114     void (*guest_close)(VirtIOSerialPort *port);
 115
 116         /* Guest is now ready to accept data (virtqueues set up). */
 117     void (*guest_ready)(VirtIOSerialPort *port);
 118
 119     /*
 120      * Guest wrote some data to the port. This data is handed over to
 121      * the app via this callback. The app should return the number of
 122      * bytes it successfully consumed.
 123      */
 124     size_t (*have_data)(VirtIOSerialPort *port, const uint8_t *buf, size_t len);
 125 };
 126
 127 /* Interface to the virtio-serial bus */
 128
 129 /*
 130  * Individual ports/apps should call this function to register the port
 131  * with the virtio-serial bus
 132  */
 133 void virtio_serial_port_qdev_register(VirtIOSerialPortInfo *info);
 134
 135 /*
 136  * Open a connection to the port
 137  *   Returns 0 on success (always).
 138  */
 139 int virtio_serial_open(VirtIOSerialPort *port);
 140
 141 /*
 142  * Close the connection to the port
 143  *   Returns 0 on success (always).
 144  */
 145 int virtio_serial_close(VirtIOSerialPort *port);
 146
 147 /*
 148  * Send data to Guest
 149  */
 150 ssize_t virtio_serial_write(VirtIOSerialPort *port, const uint8_t *buf,
 151                             size_t size);
 152
 153 /*
 154  * Query whether a guest is ready to receive data.
 155  */
 156 size_t virtio_serial_guest_ready(VirtIOSerialPort *port);
 157
 158 #endif