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 #define VIRTIO_CONSOLE_PORT_OPEN        3
  53 #define VIRTIO_CONSOLE_PORT_NAME        4
  54 #define VIRTIO_CONSOLE_PORT_REMOVE      5
  55
  56 /* == In-qemu interface == */
  57
  58 typedef struct VirtIOSerial VirtIOSerial;
  59 typedef struct VirtIOSerialBus VirtIOSerialBus;
  60 typedef struct VirtIOSerialPort VirtIOSerialPort;
  61 typedef struct VirtIOSerialPortInfo VirtIOSerialPortInfo;
  62
  63 typedef struct VirtIOSerialDevice {
  64     DeviceState qdev;
  65     VirtIOSerialPortInfo *info;
  66 } VirtIOSerialDevice;
  67
  68 /*
  69  * This is the state that's shared between all the ports.  Some of the
  70  * state is configurable via command-line options. Some of it can be
  71  * set by individual devices in their initfn routines. Some of the
  72  * state is set by the generic qdev device init routine.
  73  */
  74 struct VirtIOSerialPort {
  75     DeviceState dev;
  76     VirtIOSerialPortInfo *info;
  77
  78     QTAILQ_ENTRY(VirtIOSerialPort) next;
  79
  80     /*
  81      * This field gives us the virtio device as well as the qdev bus
  82      * that we are associated with
  83      */
  84     VirtIOSerial *vser;
  85
  86     VirtQueue *ivq, *ovq;
  87
  88     /*
  89      * This name is sent to the guest and exported via sysfs.
  90      * The guest could create symlinks based on this information.
  91      * The name is in the reverse fqdn format, like org.qemu.console.0
  92      */
  93     char *name;
  94
  95     /*
  96      * This id helps identify ports between the guest and the host.
  97      * The guest sends a "header" with this id with each data packet
  98      * that it sends and the host can then find out which associated
  99      * device to send out this data to
 100      */
 101     uint32_t id;
 102
 103     /* Identify if this is a port that binds with hvc in the guest */
 104     uint8_t is_console;
 105
 106     /* Is the corresponding guest device open? */
 107     bool guest_connected;
 108     /* Is this device open for IO on the host? */
 109     bool host_connected;
 110 };
 111
 112 struct VirtIOSerialPortInfo {
 113     DeviceInfo qdev;
 114     /*
 115      * The per-port (or per-app) init function that's called when a
 116      * new device is found on the bus.
 117      */
 118     int (*init)(VirtIOSerialDevice *dev);
 119     /*
 120      * Per-port exit function that's called when a port gets
 121      * hot-unplugged or removed.
 122      */
 123     int (*exit)(VirtIOSerialDevice *dev);
 124
 125     /* Callbacks for guest events */
 126         /* Guest opened device. */
 127     void (*guest_open)(VirtIOSerialPort *port);
 128         /* Guest closed device. */
 129     void (*guest_close)(VirtIOSerialPort *port);
 130
 131         /* Guest is now ready to accept data (virtqueues set up). */
 132     void (*guest_ready)(VirtIOSerialPort *port);
 133
 134     /*
 135      * Guest wrote some data to the port. This data is handed over to
 136      * the app via this callback. The app should return the number of
 137      * bytes it successfully consumed.
 138      */
 139     size_t (*have_data)(VirtIOSerialPort *port, const uint8_t *buf, size_t len);
 140 };
 141
 142 /* Interface to the virtio-serial bus */
 143
 144 /*
 145  * Individual ports/apps should call this function to register the port
 146  * with the virtio-serial bus
 147  */
 148 void virtio_serial_port_qdev_register(VirtIOSerialPortInfo *info);
 149
 150 /*
 151  * Open a connection to the port
 152  *   Returns 0 on success (always).
 153  */
 154 int virtio_serial_open(VirtIOSerialPort *port);
 155
 156 /*
 157  * Close the connection to the port
 158  *   Returns 0 on success (always).
 159  */
 160 int virtio_serial_close(VirtIOSerialPort *port);
 161
 162 /*
 163  * Send data to Guest
 164  */
 165 ssize_t virtio_serial_write(VirtIOSerialPort *port, const uint8_t *buf,
 166                             size_t size);
 167
 168 /*
 169  * Query whether a guest is ready to receive data.
 170  */
 171 size_t virtio_serial_guest_ready(VirtIOSerialPort *port);
 172
 173 #endif