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 "sysemu/char.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     CharDriverState *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         qemu_chr_fe_write(scon->chr, buf, size);
  93     }
  94 }
  95
  96 /* functions to be called by event facility */
  97
  98 static bool can_handle_event(uint8_t type)
  99 {
 100     return type == SCLP_EVENT_MESSAGE || type == SCLP_EVENT_PMSGCMD;
 101 }
 102
 103 static unsigned int send_mask(void)
 104 {
 105     return SCLP_EVENT_MASK_OP_CMD | SCLP_EVENT_MASK_PMSGCMD;
 106 }
 107
 108 static unsigned int receive_mask(void)
 109 {
 110     return SCLP_EVENT_MASK_MSG | SCLP_EVENT_MASK_PMSGCMD;
 111 }
 112
 113 /*
 114  * Triggered by SCLP's read_event_data
 115  * - convert ASCII byte stream to EBCDIC and
 116  * - copy converted data into provided (SCLP) buffer
 117  */
 118 static int get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
 119                             int avail)
 120 {
 121     int len;
 122
 123     SCLPConsoleLM *cons = SCLPLM_CONSOLE(event);
 124
 125     len = cons->length;
 126     /* data need to fit into provided SCLP buffer */
 127     if (len > avail) {
 128         return 1;
 129     }
 130
 131     ebcdic_put(buf, (char *)&cons->buf, len);
 132     *size = len;
 133     cons->length = 0;
 134     /* data provided and no more data pending */
 135     event->event_pending = false;
 136     qemu_notify_event();
 137     return 0;
 138 }
 139
 140 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
 141                            int *slen)
 142 {
 143     int avail, rc;
 144     size_t src_len;
 145     uint8_t *to;
 146     OprtnsCommand *oc = (OprtnsCommand *) evt_buf_hdr;
 147
 148     if (!event->event_pending) {
 149         /* no data pending */
 150         return 0;
 151     }
 152
 153     to = (uint8_t *)&oc->data;
 154     avail = *slen - sizeof(OprtnsCommand);
 155     rc = get_console_data(event, to, &src_len, avail);
 156     if (rc) {
 157         /* data didn't fit, try next SCCB */
 158         return 1;
 159     }
 160
 161     oc->message_unit.mdmsu.gds_id = GDS_ID_MDSMU;
 162     oc->message_unit.mdmsu.length = cpu_to_be16(sizeof(struct MDMSU));
 163
 164     oc->message_unit.cpmsu.gds_id = GDS_ID_CPMSU;
 165     oc->message_unit.cpmsu.length =
 166         cpu_to_be16(sizeof(struct MDMSU) - sizeof(GdsVector));
 167
 168     oc->message_unit.text_command.gds_id = GDS_ID_TEXTCMD;
 169     oc->message_unit.text_command.length =
 170         cpu_to_be16(sizeof(struct MDMSU) - (2 * sizeof(GdsVector)));
 171
 172     oc->message_unit.self_def_text_message.key = GDS_KEY_SELFDEFTEXTMSG;
 173     oc->message_unit.self_def_text_message.length =
 174         cpu_to_be16(sizeof(struct MDMSU) - (3 * sizeof(GdsVector)));
 175
 176     oc->message_unit.text_message.key = GDS_KEY_TEXTMSG;
 177     oc->message_unit.text_message.length =
 178         cpu_to_be16(sizeof(GdsSubvector) + src_len);
 179
 180     oc->header.length = cpu_to_be16(sizeof(OprtnsCommand) + src_len);
 181     oc->header.type = SCLP_EVENT_OPRTNS_COMMAND;
 182     *slen = avail - src_len;
 183
 184     return 1;
 185 }
 186
 187 /*
 188  * Triggered by SCLP's write_event_data
 189  *  - write console data to character layer
 190  *  returns < 0 if an error occurred
 191  */
 192 static int write_console_data(SCLPEvent *event, const uint8_t *buf, int len)
 193 {
 194     int ret = 0;
 195     const uint8_t *buf_offset;
 196
 197     SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
 198
 199     if (!scon->chr) {
 200         /* If there's no backend, we can just say we consumed all data. */
 201         return len;
 202     }
 203
 204     buf_offset = buf;
 205     while (len > 0) {
 206         ret = qemu_chr_fe_write(scon->chr, buf, len);
 207         if (ret == 0) {
 208             /* a pty doesn't seem to be connected - no error */
 209             len = 0;
 210         } else if (ret == -EAGAIN || (ret > 0 && ret < len)) {
 211             len -= ret;
 212             buf_offset += ret;
 213         } else {
 214             len = 0;
 215         }
 216     }
 217
 218     return ret;
 219 }
 220
 221 static int process_mdb(SCLPEvent *event, MDBO *mdbo)
 222 {
 223     int rc;
 224     int len;
 225     uint8_t buffer[SIZE_BUFFER];
 226
 227     len = be16_to_cpu(mdbo->length);
 228     len -= sizeof(mdbo->length) + sizeof(mdbo->type)
 229             + sizeof(mdbo->mto.line_type_flags)
 230             + sizeof(mdbo->mto.alarm_control)
 231             + sizeof(mdbo->mto._reserved);
 232
 233     assert(len <= SIZE_BUFFER);
 234
 235     /* convert EBCDIC SCLP contents to ASCII console message */
 236     ascii_put(buffer, mdbo->mto.message, len);
 237     rc = write_console_data(event, (uint8_t *)NEWLINE, 1);
 238     if (rc < 0) {
 239         return rc;
 240     }
 241     return write_console_data(event, buffer, len);
 242 }
 243
 244 static int write_event_data(SCLPEvent *event, EventBufferHeader *ebh)
 245 {
 246     int len;
 247     int written;
 248     int errors = 0;
 249     MDBO *mdbo;
 250     SclpMsg *data = (SclpMsg *) ebh;
 251     SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
 252
 253     len = be16_to_cpu(data->mdb.header.length);
 254     if (len < sizeof(data->mdb.header)) {
 255         return SCLP_RC_INCONSISTENT_LENGTHS;
 256     }
 257     len -= sizeof(data->mdb.header);
 258
 259     /* first check message buffers */
 260     mdbo = data->mdb.mdbo;
 261     while (len > 0) {
 262         if (be16_to_cpu(mdbo->length) > len
 263                 || be16_to_cpu(mdbo->length) == 0) {
 264             return SCLP_RC_INCONSISTENT_LENGTHS;
 265         }
 266         len -= be16_to_cpu(mdbo->length);
 267         mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
 268     }
 269
 270     /* then execute */
 271     len = be16_to_cpu(data->mdb.header.length) - sizeof(data->mdb.header);
 272     mdbo = data->mdb.mdbo;
 273     while (len > 0) {
 274         switch (be16_to_cpu(mdbo->type)) {
 275         case MESSAGE_TEXT:
 276             /* message text object */
 277             written = process_mdb(event, mdbo);
 278             if (written < 0) {
 279                 /* character layer error */
 280                 errors++;
 281             }
 282             break;
 283         default: /* ignore */
 284             break;
 285         }
 286         len -= be16_to_cpu(mdbo->length);
 287         mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
 288     }
 289     if (errors) {
 290         scon->write_errors += errors;
 291     }
 292     data->header.flags = SCLP_EVENT_BUFFER_ACCEPTED;
 293
 294     return SCLP_RC_NORMAL_COMPLETION;
 295 }
 296
 297 /* functions for live migration */
 298
 299 static const VMStateDescription vmstate_sclplmconsole = {
 300     .name = "sclplmconsole",
 301     .version_id = 0,
 302     .minimum_version_id = 0,
 303     .fields = (VMStateField[]) {
 304         VMSTATE_BOOL(event.event_pending, SCLPConsoleLM),
 305         VMSTATE_UINT32(write_errors, SCLPConsoleLM),
 306         VMSTATE_UINT32(length, SCLPConsoleLM),
 307         VMSTATE_UINT8_ARRAY(buf, SCLPConsoleLM, SIZE_CONSOLE_BUFFER),
 308         VMSTATE_END_OF_LIST()
 309      }
 310 };
 311
 312 /* qemu object creation and initialization functions */
 313
 314 /* tell character layer our call-back functions */
 315
 316 static int console_init(SCLPEvent *event)
 317 {
 318     static bool console_available;
 319
 320     SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
 321
 322     if (console_available) {
 323         error_report("Multiple line-mode operator consoles are not supported");
 324         return -1;
 325     }
 326     console_available = true;
 327
 328     if (scon->chr) {
 329         qemu_chr_add_handlers(scon->chr, chr_can_read, chr_read, NULL, scon);
 330     }
 331
 332     return 0;
 333 }
 334
 335 static int console_exit(SCLPEvent *event)
 336 {
 337     return 0;
 338 }
 339
 340 static void console_reset(DeviceState *dev)
 341 {
 342    SCLPEvent *event = SCLP_EVENT(dev);
 343    SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
 344
 345    event->event_pending = false;
 346    scon->length = 0;
 347    scon->write_errors = 0;
 348 }
 349
 350 static Property console_properties[] = {
 351     DEFINE_PROP_CHR("chardev", SCLPConsoleLM, chr),
 352     DEFINE_PROP_UINT32("write_errors", SCLPConsoleLM, write_errors, 0),
 353     DEFINE_PROP_BOOL("echo", SCLPConsoleLM, echo, true),
 354     DEFINE_PROP_END_OF_LIST(),
 355 };
 356
 357 static void console_class_init(ObjectClass *klass, void *data)
 358 {
 359     DeviceClass *dc = DEVICE_CLASS(klass);
 360     SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
 361
 362     dc->props = console_properties;
 363     dc->reset = console_reset;
 364     dc->vmsd = &vmstate_sclplmconsole;
 365     ec->init = console_init;
 366     ec->exit = console_exit;
 367     ec->get_send_mask = send_mask;
 368     ec->get_receive_mask = receive_mask;
 369     ec->can_handle_event = can_handle_event;
 370     ec->read_event_data = read_event_data;
 371     ec->write_event_data = write_event_data;
 372     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 373 }
 374
 375 static const TypeInfo sclp_console_info = {
 376     .name          = "sclplmconsole",
 377     .parent        = TYPE_SCLP_EVENT,
 378     .instance_size = sizeof(SCLPConsoleLM),
 379     .class_init    = console_class_init,
 380     .class_size    = sizeof(SCLPEventClass),
 381 };
 382
 383 static void register_types(void)
 384 {
 385     type_register_static(&sclp_console_info);
 386 }
 387
 388 type_init(register_types)