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