hw/char/sclpconsole-lm.c

   1 /*
   2  * SCLP event types
   3  *    Operations Command - Line Mode input
   4  *    Message            - Line Mode output
   5  *
   6  * Copyright IBM, Corp. 2013
   7  *
   8  * Authors:
   9  *  Heinz Graalfs <graalfs@linux.vnet.ibm.com>
  10  *
  11  * This work is licensed under the terms of the GNU GPL, version 2 or (at your
  12  * option) any later version.  See the COPYING file in the top-level directory.
  13  *
  14  */
  15
  16 #include "qemu/osdep.h"
  17 #include "hw/qdev.h"
  18 #include "qemu/thread.h"
  19 #include "qemu/error-report.h"
  20 #include "chardev/char-fe.h"
  21
  22 #include "hw/s390x/sclp.h"
  23 #include "hw/s390x/event-facility.h"
  24 #include "hw/s390x/ebcdic.h"
  25
  26 #define SIZE_BUFFER 4096
  27 #define NEWLINE     "\n"
  28
  29 typedef struct OprtnsCommand {
  30     EventBufferHeader header;
  31     MDMSU message_unit;
  32     char data[0];
  33 } QEMU_PACKED OprtnsCommand;
  34
  35 /* max size for line-mode data in 4K SCCB page */
  36 #define SIZE_CONSOLE_BUFFER (SCCB_DATA_LEN - sizeof(OprtnsCommand))
  37
  38 typedef struct SCLPConsoleLM {
  39     SCLPEvent event;
  40     CharBackend chr;
  41     bool echo;                  /* immediate echo of input if true        */
  42     uint32_t write_errors;      /* errors writing to char layer           */
  43     uint32_t length;            /* length of byte stream in buffer        */
  44     uint8_t buf[SIZE_CONSOLE_BUFFER];
  45 } SCLPConsoleLM;
  46
  47 #define TYPE_SCLPLM_CONSOLE "sclplmconsole"
  48 #define SCLPLM_CONSOLE(obj) \
  49     OBJECT_CHECK(SCLPConsoleLM, (obj), TYPE_SCLPLM_CONSOLE)
  50
  51 /*
  52 *  Character layer call-back functions
  53  *
  54  * Allow 1 character at a time
  55  *
  56  * Accumulate bytes from character layer in console buffer,
  57  * event_pending is set when a newline character is encountered
  58  *
  59  * The maximum command line length is limited by the maximum
  60  * space available in an SCCB. Line mode console input is sent
  61  * truncated to the guest in case it doesn't fit into the SCCB.
  62  */
  63
  64 static int chr_can_read(void *opaque)
  65 {
  66     SCLPConsoleLM *scon = opaque;
  67
  68     if (scon->event.event_pending) {
  69         return 0;
  70     }
  71     return 1;
  72 }
  73
  74 static void chr_read(void *opaque, const uint8_t *buf, int size)
  75 {
  76     SCLPConsoleLM *scon = opaque;
  77
  78     assert(size == 1);
  79
  80     if (*buf == '\r' || *buf == '\n') {
  81         scon->event.event_pending = true;
  82         sclp_service_interrupt(0);
  83         return;
  84     }
  85     if (scon->length == SIZE_CONSOLE_BUFFER) {
  86         /* Eat the character, but still process CR and LF.  */
  87         return;
  88     }
  89     scon->buf[scon->length] = *buf;
  90     scon->length += 1;
  91     if (scon->echo) {
  92         /* XXX this blocks entire thread. Rewrite to use
  93          * qemu_chr_fe_write and background I/O callbacks */
  94         qemu_chr_fe_write_all(&scon->chr, buf, size);
  95     }
  96 }
  97
  98 /* functions to be called by event facility */
  99
 100 static bool can_handle_event(uint8_t type)
 101 {
 102     return type == SCLP_EVENT_MESSAGE || type == SCLP_EVENT_PMSGCMD;
 103 }
 104
 105 static unsigned int send_mask(void)
 106 {
 107     return SCLP_EVENT_MASK_OP_CMD | SCLP_EVENT_MASK_PMSGCMD;
 108 }
 109
 110 static unsigned int receive_mask(void)
 111 {
 112     return SCLP_EVENT_MASK_MSG | SCLP_EVENT_MASK_PMSGCMD;
 113 }
 114
 115 /*
 116  * Triggered by SCLP's read_event_data
 117  * - convert ASCII byte stream to EBCDIC and
 118  * - copy converted data into provided (SCLP) buffer
 119  */
 120 static int get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
 121                             int avail)
 122 {
 123     int len;
 124
 125     SCLPConsoleLM *cons = SCLPLM_CONSOLE(event);
 126
 127     len = cons->length;
 128     /* data need to fit into provided SCLP buffer */
 129     if (len > avail) {
 130         return 1;
 131     }
 132
 133     ebcdic_put(buf, (char *)&cons->buf, len);
 134     *size = len;
 135     cons->length = 0;
 136     /* data provided and no more data pending */
 137     event->event_pending = false;
 138     qemu_notify_event();
 139     return 0;
 140 }
 141
 142 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
 143                            int *slen)
 144 {
 145     int avail, rc;
 146     size_t src_len;
 147     uint8_t *to;
 148     OprtnsCommand *oc = (OprtnsCommand *) evt_buf_hdr;
 149
 150     if (!event->event_pending) {
 151         /* no data pending */
 152         return 0;
 153     }
 154
 155     to = (uint8_t *)&oc->data;
 156     avail = *slen - sizeof(OprtnsCommand);
 157     rc = get_console_data(event, to, &src_len, avail);
 158     if (rc) {
 159         /* data didn't fit, try next SCCB */
 160         return 1;
 161     }
 162
 163     oc->message_unit.mdmsu.gds_id = GDS_ID_MDSMU;
 164     oc->message_unit.mdmsu.length = cpu_to_be16(sizeof(struct MDMSU));
 165
 166     oc->message_unit.cpmsu.gds_id = GDS_ID_CPMSU;
 167     oc->message_unit.cpmsu.length =
 168         cpu_to_be16(sizeof(struct MDMSU) - sizeof(GdsVector));
 169
 170     oc->message_unit.text_command.gds_id = GDS_ID_TEXTCMD;
 171     oc->message_unit.text_command.length =
 172         cpu_to_be16(sizeof(struct MDMSU) - (2 * sizeof(GdsVector)));
 173
 174     oc->message_unit.self_def_text_message.key = GDS_KEY_SELFDEFTEXTMSG;
 175     oc->message_unit.self_def_text_message.length =
 176         cpu_to_be16(sizeof(struct MDMSU) - (3 * sizeof(GdsVector)));
 177
 178     oc->message_unit.text_message.key = GDS_KEY_TEXTMSG;
 179     oc->message_unit.text_message.length =
 180         cpu_to_be16(sizeof(GdsSubvector) + src_len);
 181
 182     oc->header.length = cpu_to_be16(sizeof(OprtnsCommand) + src_len);
 183     oc->header.type = SCLP_EVENT_OPRTNS_COMMAND;
 184     *slen = avail - src_len;
 185
 186     return 1;
 187 }
 188
 189 /*
 190  * Triggered by SCLP's write_event_data
 191  *  - write console data to character layer
 192  *  returns < 0 if an error occurred
 193  */
 194 static int write_console_data(SCLPEvent *event, const uint8_t *buf, int len)
 195 {
 196     SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
 197
 198     if (!qemu_chr_fe_get_driver(&scon->chr)) {
 199         /* If there's no backend, we can just say we consumed all data. */
 200         return len;
 201     }
 202
 203     /* XXX this blocks entire thread. Rewrite to use
 204      * qemu_chr_fe_write and background I/O callbacks */
 205     return qemu_chr_fe_write_all(&scon->chr, buf, len);
 206 }
 207
 208 static int process_mdb(SCLPEvent *event, MDBO *mdbo)
 209 {
 210     int rc;
 211     int len;
 212     uint8_t buffer[SIZE_BUFFER];
 213
 214     len = be16_to_cpu(mdbo->length);
 215     len -= sizeof(mdbo->length) + sizeof(mdbo->type)
 216             + sizeof(mdbo->mto.line_type_flags)
 217             + sizeof(mdbo->mto.alarm_control)
 218             + sizeof(mdbo->mto._reserved);
 219
 220     assert(len <= SIZE_BUFFER);
 221
 222     /* convert EBCDIC SCLP contents to ASCII console message */
 223     ascii_put(buffer, mdbo->mto.message, len);
 224     rc = write_console_data(event, (uint8_t *)NEWLINE, 1);
 225     if (rc < 0) {
 226         return rc;
 227     }
 228     return write_console_data(event, buffer, len);
 229 }
 230
 231 static int write_event_data(SCLPEvent *event, EventBufferHeader *ebh)
 232 {
 233     int len;
 234     int written;
 235     int errors = 0;
 236     MDBO *mdbo;
 237     SclpMsg *data = (SclpMsg *) ebh;
 238     SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
 239
 240     len = be16_to_cpu(data->mdb.header.length);
 241     if (len < sizeof(data->mdb.header)) {
 242         return SCLP_RC_INCONSISTENT_LENGTHS;
 243     }
 244     len -= sizeof(data->mdb.header);
 245
 246     /* first check message buffers */
 247     mdbo = data->mdb.mdbo;
 248     while (len > 0) {
 249         if (be16_to_cpu(mdbo->length) > len
 250                 || be16_to_cpu(mdbo->length) == 0) {
 251             return SCLP_RC_INCONSISTENT_LENGTHS;
 252         }
 253         len -= be16_to_cpu(mdbo->length);
 254         mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
 255     }
 256
 257     /* then execute */
 258     len = be16_to_cpu(data->mdb.header.length) - sizeof(data->mdb.header);
 259     mdbo = data->mdb.mdbo;
 260     while (len > 0) {
 261         switch (be16_to_cpu(mdbo->type)) {
 262         case MESSAGE_TEXT:
 263             /* message text object */
 264             written = process_mdb(event, mdbo);
 265             if (written < 0) {
 266                 /* character layer error */
 267                 errors++;
 268             }
 269             break;
 270         default: /* ignore */
 271             break;
 272         }
 273         len -= be16_to_cpu(mdbo->length);
 274         mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
 275     }
 276     if (errors) {
 277         scon->write_errors += errors;
 278     }
 279     data->header.flags = SCLP_EVENT_BUFFER_ACCEPTED;
 280
 281     return SCLP_RC_NORMAL_COMPLETION;
 282 }
 283
 284 /* functions for live migration */
 285
 286 static const VMStateDescription vmstate_sclplmconsole = {
 287     .name = "sclplmconsole",
 288     .version_id = 0,
 289     .minimum_version_id = 0,
 290     .fields = (VMStateField[]) {
 291         VMSTATE_BOOL(event.event_pending, SCLPConsoleLM),
 292         VMSTATE_UINT32(write_errors, SCLPConsoleLM),
 293         VMSTATE_UINT32(length, SCLPConsoleLM),
 294         VMSTATE_UINT8_ARRAY(buf, SCLPConsoleLM, SIZE_CONSOLE_BUFFER),
 295         VMSTATE_END_OF_LIST()
 296      }
 297 };
 298
 299 /* qemu object creation and initialization functions */
 300
 301 /* tell character layer our call-back functions */
 302
 303 static int console_init(SCLPEvent *event)
 304 {
 305     static bool console_available;
 306
 307     SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
 308
 309     if (console_available) {
 310         error_report("Multiple line-mode operator consoles are not supported");
 311         return -1;
 312     }
 313     console_available = true;
 314
 315     qemu_chr_fe_set_handlers(&scon->chr, chr_can_read,
 316                              chr_read, NULL, scon, NULL, true);
 317
 318     return 0;
 319 }
 320
 321 static int console_exit(SCLPEvent *event)
 322 {
 323     return 0;
 324 }
 325
 326 static void console_reset(DeviceState *dev)
 327 {
 328    SCLPEvent *event = SCLP_EVENT(dev);
 329    SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
 330
 331    event->event_pending = false;
 332    scon->length = 0;
 333    scon->write_errors = 0;
 334 }
 335
 336 static Property console_properties[] = {
 337     DEFINE_PROP_CHR("chardev", SCLPConsoleLM, chr),
 338     DEFINE_PROP_UINT32("write_errors", SCLPConsoleLM, write_errors, 0),
 339     DEFINE_PROP_BOOL("echo", SCLPConsoleLM, echo, true),
 340     DEFINE_PROP_END_OF_LIST(),
 341 };
 342
 343 static void console_class_init(ObjectClass *klass, void *data)
 344 {
 345     DeviceClass *dc = DEVICE_CLASS(klass);
 346     SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
 347
 348     dc->props = console_properties;
 349     dc->reset = console_reset;
 350     dc->vmsd = &vmstate_sclplmconsole;
 351     ec->init = console_init;
 352     ec->exit = console_exit;
 353     ec->get_send_mask = send_mask;
 354     ec->get_receive_mask = receive_mask;
 355     ec->can_handle_event = can_handle_event;
 356     ec->read_event_data = read_event_data;
 357     ec->write_event_data = write_event_data;
 358     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 359 }
 360
 361 static const TypeInfo sclp_console_info = {
 362     .name          = "sclplmconsole",
 363     .parent        = TYPE_SCLP_EVENT,
 364     .instance_size = sizeof(SCLPConsoleLM),
 365     .class_init    = console_class_init,
 366     .class_size    = sizeof(SCLPEventClass),
 367 };
 368
 369 static void register_types(void)
 370 {
 371     type_register_static(&sclp_console_info);
 372 }
 373
 374 type_init(register_types)