hw/virtio-console.c

   1 /*
   2  * Virtio Console and Generic Serial Port Devices
   3  *
   4  * Copyright Red Hat, Inc. 2009, 2010
   5  *
   6  * Authors:
   7  *  Amit Shah <amit.shah@redhat.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2.  See
  10  * the COPYING file in the top-level directory.
  11  */
  12
  13 #include "qemu-char.h"
  14 #include "qemu-error.h"
  15 #include "virtio-serial.h"
  16
  17 typedef struct VirtConsole {
  18     VirtIOSerialPort port;
  19     CharDriverState *chr;
  20 } VirtConsole;
  21
  22
  23 /* Callback function that's called when the guest sends us data */
  24 static ssize_t flush_buf(VirtIOSerialPort *port, const uint8_t *buf, size_t len)
  25 {
  26     VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
  27
  28     return qemu_chr_write(vcon->chr, buf, len);
  29 }
  30
  31 /* Readiness of the guest to accept data on a port */
  32 static int chr_can_read(void *opaque)
  33 {
  34     VirtConsole *vcon = opaque;
  35
  36     return virtio_serial_guest_ready(&vcon->port);
  37 }
  38
  39 /* Send data from a char device over to the guest */
  40 static void chr_read(void *opaque, const uint8_t *buf, int size)
  41 {
  42     VirtConsole *vcon = opaque;
  43
  44     virtio_serial_write(&vcon->port, buf, size);
  45 }
  46
  47 static void chr_event(void *opaque, int event)
  48 {
  49     VirtConsole *vcon = opaque;
  50
  51     switch (event) {
  52     case CHR_EVENT_OPENED:
  53         virtio_serial_open(&vcon->port);
  54         break;
  55     case CHR_EVENT_CLOSED:
  56         virtio_serial_close(&vcon->port);
  57         break;
  58     }
  59 }
  60
  61 static int generic_port_init(VirtConsole *vcon, VirtIOSerialPort *port)
  62 {
  63     if (vcon->chr) {
  64         qemu_chr_add_handlers(vcon->chr, chr_can_read, chr_read, chr_event,
  65                               vcon);
  66         vcon->port.info->have_data = flush_buf;
  67     }
  68     return 0;
  69 }
  70
  71 /* Virtio Console Ports */
  72 static int virtconsole_initfn(VirtIOSerialPort *port)
  73 {
  74     VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
  75
  76     port->is_console = true;
  77     return generic_port_init(vcon, port);
  78 }
  79
  80 static int virtconsole_exitfn(VirtIOSerialPort *port)
  81 {
  82     VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
  83
  84     if (vcon->chr) {
  85         /*
  86          * Instead of closing the chardev, free it so it can be used
  87          * for other purposes.
  88          */
  89         qemu_chr_add_handlers(vcon->chr, NULL, NULL, NULL, NULL);
  90     }
  91
  92     return 0;
  93 }
  94
  95 static VirtIOSerialPortInfo virtconsole_info = {
  96     .qdev.name     = "virtconsole",
  97     .qdev.size     = sizeof(VirtConsole),
  98     .init          = virtconsole_initfn,
  99     .exit          = virtconsole_exitfn,
 100     .qdev.props = (Property[]) {
 101         DEFINE_PROP_UINT8("is_console", VirtConsole, port.is_console, 1),
 102         DEFINE_PROP_UINT32("nr", VirtConsole, port.id, VIRTIO_CONSOLE_BAD_ID),
 103         DEFINE_PROP_CHR("chardev", VirtConsole, chr),
 104         DEFINE_PROP_STRING("name", VirtConsole, port.name),
 105         DEFINE_PROP_END_OF_LIST(),
 106     },
 107 };
 108
 109 static void virtconsole_register(void)
 110 {
 111     virtio_serial_port_qdev_register(&virtconsole_info);
 112 }
 113 device_init(virtconsole_register)
 114
 115 /* Generic Virtio Serial Ports */
 116 static int virtserialport_initfn(VirtIOSerialPort *port)
 117 {
 118     VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
 119
 120     if (port->id == 0) {
 121         /*
 122          * Disallow a generic port at id 0, that's reserved for
 123          * console ports.
 124          */
 125         error_report("Port number 0 on virtio-serial devices reserved for virtconsole devices for backward compatibility.");
 126         return -1;
 127     }
 128     return generic_port_init(vcon, port);
 129 }
 130
 131 static VirtIOSerialPortInfo virtserialport_info = {
 132     .qdev.name     = "virtserialport",
 133     .qdev.size     = sizeof(VirtConsole),
 134     .init          = virtserialport_initfn,
 135     .exit          = virtconsole_exitfn,
 136     .qdev.props = (Property[]) {
 137         DEFINE_PROP_UINT32("nr", VirtConsole, port.id, VIRTIO_CONSOLE_BAD_ID),
 138         DEFINE_PROP_CHR("chardev", VirtConsole, chr),
 139         DEFINE_PROP_STRING("name", VirtConsole, port.name),
 140         DEFINE_PROP_END_OF_LIST(),
 141     },
 142 };
 143
 144 static void virtserialport_register(void)
 145 {
 146     virtio_serial_port_qdev_register(&virtserialport_info);
 147 }
 148 device_init(virtserialport_register)