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 } QEMU_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 struct virtio_serial_conf {
  49     /* Max. number of ports we can have for a virtio-serial device */
  50     uint32_t max_virtserial_ports;
  51 };
  52
  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
  62
  63 /* == In-qemu interface == */
  64
  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)
  72
  73 typedef struct VirtIOSerial VirtIOSerial;
  74 typedef struct VirtIOSerialBus VirtIOSerialBus;
  75 typedef struct VirtIOSerialPort VirtIOSerialPort;
  76
  77 typedef struct VirtIOSerialPortClass {
  78     DeviceClass parent_class;
  79
  80     /* Is this a device that binds with hvc in the guest? */
  81     bool is_console;
  82
  83     /*
  84      * The per-port (or per-app) init function that's called when a
  85      * new device is found on the bus.
  86      */
  87     int (*init)(VirtIOSerialPort *port);
  88     /*
  89      * Per-port exit function that's called when a port gets
  90      * hot-unplugged or removed.
  91      */
  92     int (*exit)(VirtIOSerialPort *port);
  93
  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);
  99
 100         /* Guest is now ready to accept data (virtqueues set up). */
 101     void (*guest_ready)(VirtIOSerialPort *port);
 102
 103     /*
 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.
 107      */
 108     ssize_t (*have_data)(VirtIOSerialPort *port, const uint8_t *buf,
 109                          size_t len);
 110 } VirtIOSerialPortClass;
 111
 112 /*
 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.
 117  */
 118 struct VirtIOSerialPort {
 119     DeviceState dev;
 120
 121     QTAILQ_ENTRY(VirtIOSerialPort) next;
 122
 123     /*
 124      * This field gives us the virtio device as well as the qdev bus
 125      * that we are associated with
 126      */
 127     VirtIOSerial *vser;
 128
 129     VirtQueue *ivq, *ovq;
 130
 131     /*
 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
 135      */
 136     char *name;
 137
 138     /*
 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
 143      */
 144     uint32_t id;
 145
 146     /*
 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.
 153      */
 154     VirtQueueElement elem;
 155
 156     /*
 157      * The index and the offset into the iov buffer that was popped in
 158      * elem above.
 159      */
 160     uint32_t iov_idx;
 161     uint64_t iov_offset;
 162
 163     /*
 164      * When unthrottling we use a bottom-half to call flush_queued_data.
 165      */
 166     QEMUBH *bh;
 167
 168     /* Is the corresponding guest device open? */
 169     bool guest_connected;
 170     /* Is this device open for IO on the host? */
 171     bool host_connected;
 172     /* Do apps not want to receive data? */
 173     bool throttled;
 174 };
 175
 176 /* Interface to the virtio-serial bus */
 177
 178 /*
 179  * Open a connection to the port
 180  *   Returns 0 on success (always).
 181  */
 182 int virtio_serial_open(VirtIOSerialPort *port);
 183
 184 /*
 185  * Close the connection to the port
 186  *   Returns 0 on success (always).
 187  */
 188 int virtio_serial_close(VirtIOSerialPort *port);
 189
 190 /*
 191  * Send data to Guest
 192  */
 193 ssize_t virtio_serial_write(VirtIOSerialPort *port, const uint8_t *buf,
 194                             size_t size);
 195
 196 /*
 197  * Query whether a guest is ready to receive data.
 198  */
 199 size_t virtio_serial_guest_ready(VirtIOSerialPort *port);
 200
 201 /*
 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'
 204  * value here.
 205  */
 206 void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle);
 207
 208 #endif