hw/char/sclpconsole.c

   1 /*
   2  * SCLP event type
   3  *    Ascii Console Data (VT220 Console)
   4  *
   5  * Copyright IBM, Corp. 2012
   6  *
   7  * Authors:
   8  *  Heinz Graalfs <graalfs@de.ibm.com>
   9  *
  10  * This work is licensed under the terms of the GNU GPL, version 2 or (at your
  11  * option) any later version.  See the COPYING file in the top-level directory.
  12  *
  13  */
  14
  15 #include "qemu/osdep.h"
  16 #include "hw/qdev.h"
  17 #include "qemu/thread.h"
  18 #include "qemu/error-report.h"
  19
  20 #include "hw/s390x/sclp.h"
  21 #include "hw/s390x/event-facility.h"
  22 #include "chardev/char-fe.h"
  23
  24 typedef struct ASCIIConsoleData {
  25     EventBufferHeader ebh;
  26     char data[0];
  27 } QEMU_PACKED ASCIIConsoleData;
  28
  29 /* max size for ASCII data in 4K SCCB page */
  30 #define SIZE_BUFFER_VT220 4080
  31
  32 typedef struct SCLPConsole {
  33     SCLPEvent event;
  34     CharBackend chr;
  35     uint8_t iov[SIZE_BUFFER_VT220];
  36     uint32_t iov_sclp;      /* offset in buf for SCLP read operation       */
  37     uint32_t iov_bs;        /* offset in buf for char layer read operation */
  38     uint32_t iov_data_len;  /* length of byte stream in buffer             */
  39     uint32_t iov_sclp_rest; /* length of byte stream not read via SCLP     */
  40     bool notify;            /* qemu_notify_event() req'd if true           */
  41 } SCLPConsole;
  42
  43 #define TYPE_SCLP_CONSOLE "sclpconsole"
  44 #define SCLP_CONSOLE(obj) \
  45     OBJECT_CHECK(SCLPConsole, (obj), TYPE_SCLP_CONSOLE)
  46
  47 /* character layer call-back functions */
  48
  49 /* Return number of bytes that fit into iov buffer */
  50 static int chr_can_read(void *opaque)
  51 {
  52     SCLPConsole *scon = opaque;
  53     int avail = SIZE_BUFFER_VT220 - scon->iov_data_len;
  54
  55     if (avail == 0) {
  56         scon->notify = true;
  57     }
  58     return avail;
  59 }
  60
  61 /* Send data from a char device over to the guest */
  62 static void chr_read(void *opaque, const uint8_t *buf, int size)
  63 {
  64     SCLPConsole *scon = opaque;
  65
  66     assert(scon);
  67     /* read data must fit into current buffer */
  68     assert(size <= SIZE_BUFFER_VT220 - scon->iov_data_len);
  69
  70     /* put byte-stream from character layer into buffer */
  71     memcpy(&scon->iov[scon->iov_bs], buf, size);
  72     scon->iov_data_len += size;
  73     scon->iov_sclp_rest += size;
  74     scon->iov_bs += size;
  75     scon->event.event_pending = true;
  76     sclp_service_interrupt(0);
  77 }
  78
  79 /* functions to be called by event facility */
  80
  81 static bool can_handle_event(uint8_t type)
  82 {
  83     return type == SCLP_EVENT_ASCII_CONSOLE_DATA;
  84 }
  85
  86 static unsigned int send_mask(void)
  87 {
  88     return SCLP_EVENT_MASK_MSG_ASCII;
  89 }
  90
  91 static unsigned int receive_mask(void)
  92 {
  93     return SCLP_EVENT_MASK_MSG_ASCII;
  94 }
  95
  96 /* triggered by SCLP's read_event_data -
  97  * copy console data byte-stream into provided (SCLP) buffer
  98  */
  99 static void get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
 100                              int avail)
 101 {
 102     SCLPConsole *cons = SCLP_CONSOLE(event);
 103
 104     /* first byte is hex 0 saying an ascii string follows */
 105     *buf++ = '\0';
 106     avail--;
 107     /* if all data fit into provided SCLP buffer */
 108     if (avail >= cons->iov_sclp_rest) {
 109         /* copy character byte-stream to SCLP buffer */
 110         memcpy(buf, &cons->iov[cons->iov_sclp], cons->iov_sclp_rest);
 111         *size = cons->iov_sclp_rest + 1;
 112         cons->iov_sclp = 0;
 113         cons->iov_bs = 0;
 114         cons->iov_data_len = 0;
 115         cons->iov_sclp_rest = 0;
 116         event->event_pending = false;
 117         /* data provided and no more data pending */
 118     } else {
 119         /* if provided buffer is too small, just copy part */
 120         memcpy(buf, &cons->iov[cons->iov_sclp], avail);
 121         *size = avail + 1;
 122         cons->iov_sclp_rest -= avail;
 123         cons->iov_sclp += avail;
 124         /* more data pending */
 125     }
 126     if (cons->notify) {
 127         cons->notify = false;
 128         qemu_notify_event();
 129     }
 130 }
 131
 132 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
 133                            int *slen)
 134 {
 135     int avail;
 136     size_t src_len;
 137     uint8_t *to;
 138     ASCIIConsoleData *acd = (ASCIIConsoleData *) evt_buf_hdr;
 139
 140     if (!event->event_pending) {
 141         /* no data pending */
 142         return 0;
 143     }
 144
 145     to = (uint8_t *)&acd->data;
 146     avail = *slen - sizeof(ASCIIConsoleData);
 147     get_console_data(event, to, &src_len, avail);
 148
 149     acd->ebh.length = cpu_to_be16(sizeof(ASCIIConsoleData) + src_len);
 150     acd->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
 151     acd->ebh.flags |= SCLP_EVENT_BUFFER_ACCEPTED;
 152     *slen = avail - src_len;
 153
 154     return 1;
 155 }
 156
 157 /* triggered by SCLP's write_event_data
 158  *  - write console data to character layer
 159  *  returns < 0 if an error occurred
 160  */
 161 static ssize_t write_console_data(SCLPEvent *event, const uint8_t *buf,
 162                                   size_t len)
 163 {
 164     SCLPConsole *scon = SCLP_CONSOLE(event);
 165
 166     if (!qemu_chr_fe_backend_connected(&scon->chr)) {
 167         /* If there's no backend, we can just say we consumed all data. */
 168         return len;
 169     }
 170
 171     /* XXX this blocks entire thread. Rewrite to use
 172      * qemu_chr_fe_write and background I/O callbacks */
 173     return qemu_chr_fe_write_all(&scon->chr, buf, len);
 174 }
 175
 176 static int write_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr)
 177 {
 178     int rc;
 179     int length;
 180     ssize_t written;
 181     ASCIIConsoleData *acd = (ASCIIConsoleData *) evt_buf_hdr;
 182
 183     length = be16_to_cpu(evt_buf_hdr->length) - sizeof(EventBufferHeader);
 184     written = write_console_data(event, (uint8_t *)acd->data, length);
 185
 186     rc = SCLP_RC_NORMAL_COMPLETION;
 187     /* set event buffer accepted flag */
 188     evt_buf_hdr->flags |= SCLP_EVENT_BUFFER_ACCEPTED;
 189
 190     /* written will be zero if a pty is not connected - don't treat as error */
 191     if (written < 0) {
 192         /* event buffer not accepted due to error in character layer */
 193         evt_buf_hdr->flags &= ~(SCLP_EVENT_BUFFER_ACCEPTED);
 194         rc = SCLP_RC_CONTAINED_EQUIPMENT_CHECK;
 195     }
 196
 197     return rc;
 198 }
 199
 200 static const VMStateDescription vmstate_sclpconsole = {
 201     .name = "sclpconsole",
 202     .version_id = 0,
 203     .minimum_version_id = 0,
 204     .fields = (VMStateField[]) {
 205         VMSTATE_BOOL(event.event_pending, SCLPConsole),
 206         VMSTATE_UINT8_ARRAY(iov, SCLPConsole, SIZE_BUFFER_VT220),
 207         VMSTATE_UINT32(iov_sclp, SCLPConsole),
 208         VMSTATE_UINT32(iov_bs, SCLPConsole),
 209         VMSTATE_UINT32(iov_data_len, SCLPConsole),
 210         VMSTATE_UINT32(iov_sclp_rest, SCLPConsole),
 211         VMSTATE_END_OF_LIST()
 212      }
 213 };
 214
 215 /* qemu object creation and initialization functions */
 216
 217 /* tell character layer our call-back functions */
 218
 219 static int console_init(SCLPEvent *event)
 220 {
 221     static bool console_available;
 222
 223     SCLPConsole *scon = SCLP_CONSOLE(event);
 224
 225     if (console_available) {
 226         error_report("Multiple VT220 operator consoles are not supported");
 227         return -1;
 228     }
 229     console_available = true;
 230     qemu_chr_fe_set_handlers(&scon->chr, chr_can_read,
 231                              chr_read, NULL, NULL, scon, NULL, true);
 232
 233     return 0;
 234 }
 235
 236 static void console_reset(DeviceState *dev)
 237 {
 238    SCLPEvent *event = SCLP_EVENT(dev);
 239    SCLPConsole *scon = SCLP_CONSOLE(event);
 240
 241    event->event_pending = false;
 242    scon->iov_sclp = 0;
 243    scon->iov_bs = 0;
 244    scon->iov_data_len = 0;
 245    scon->iov_sclp_rest = 0;
 246    scon->notify = false;
 247 }
 248
 249 static int console_exit(SCLPEvent *event)
 250 {
 251     return 0;
 252 }
 253
 254 static Property console_properties[] = {
 255     DEFINE_PROP_CHR("chardev", SCLPConsole, chr),
 256     DEFINE_PROP_END_OF_LIST(),
 257 };
 258
 259 static void console_class_init(ObjectClass *klass, void *data)
 260 {
 261     DeviceClass *dc = DEVICE_CLASS(klass);
 262     SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
 263
 264     dc->props = console_properties;
 265     dc->reset = console_reset;
 266     dc->vmsd = &vmstate_sclpconsole;
 267     ec->init = console_init;
 268     ec->exit = console_exit;
 269     ec->get_send_mask = send_mask;
 270     ec->get_receive_mask = receive_mask;
 271     ec->can_handle_event = can_handle_event;
 272     ec->read_event_data = read_event_data;
 273     ec->write_event_data = write_event_data;
 274     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 275 }
 276
 277 static const TypeInfo sclp_console_info = {
 278     .name          = "sclpconsole",
 279     .parent        = TYPE_SCLP_EVENT,
 280     .instance_size = sizeof(SCLPConsole),
 281     .class_init    = console_class_init,
 282     .class_size    = sizeof(SCLPEventClass),
 283 };
 284
 285 static void register_types(void)
 286 {
 287     type_register_static(&sclp_console_info);
 288 }
 289
 290 type_init(register_types)