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 /*
  48 *  Character layer call-back functions
  49  *
  50  * Allow 1 character at a time
  51  *
  52  * Accumulate bytes from character layer in console buffer,
  53  * event_pending is set when a newline character is encountered
  54  *
  55  * The maximum command line length is limited by the maximum
  56  * space available in an SCCB. Line mode console input is sent
  57  * truncated to the guest in case it doesn't fit into the SCCB.
  58  */
  59
  60 static int chr_can_read(void *opaque)
  61 {
  62     SCLPConsoleLM *scon = opaque;
  63
  64     if (scon->event.event_pending) {
  65         return 0;
  66     }
  67     return 1;
  68 }
  69
  70 static void chr_read(void *opaque, const uint8_t *buf, int size)
  71 {
  72     SCLPConsoleLM *scon = opaque;
  73
  74     assert(size == 1);
  75
  76     if (*buf == '\r' || *buf == '\n') {
  77         scon->event.event_pending = true;
  78         sclp_service_interrupt(0);
  79         return;
  80     }
  81     if (scon->length == SIZE_CONSOLE_BUFFER) {
  82         /* Eat the character, but still process CR and LF.  */
  83         return;
  84     }
  85     scon->buf[scon->length] = *buf;
  86     scon->length += 1;
  87     if (scon->echo) {
  88         qemu_chr_fe_write(scon->chr, buf, size);
  89     }
  90 }
  91
  92 /* functions to be called by event facility */
  93
  94 static bool can_handle_event(uint8_t type)
  95 {
  96     return type == SCLP_EVENT_MESSAGE || type == SCLP_EVENT_PMSGCMD;
  97 }
  98
  99 static unsigned int send_mask(void)
 100 {
 101     return SCLP_EVENT_MASK_OP_CMD | SCLP_EVENT_MASK_PMSGCMD;
 102 }
 103
 104 static unsigned int receive_mask(void)
 105 {
 106     return SCLP_EVENT_MASK_MSG | SCLP_EVENT_MASK_PMSGCMD;
 107 }
 108
 109 /*
 110  * Triggered by SCLP's read_event_data
 111  * - convert ASCII byte stream to EBCDIC and
 112  * - copy converted data into provided (SCLP) buffer
 113  */
 114 static int get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
 115                             int avail)
 116 {
 117     int len;
 118
 119     SCLPConsoleLM *cons = DO_UPCAST(SCLPConsoleLM, event, event);
 120
 121     len = cons->length;
 122     /* data need to fit into provided SCLP buffer */
 123     if (len > avail) {
 124         return 1;
 125     }
 126
 127     ebcdic_put(buf, (char *)&cons->buf, len);
 128     *size = len;
 129     cons->length = 0;
 130     /* data provided and no more data pending */
 131     event->event_pending = false;
 132     qemu_notify_event();
 133     return 0;
 134 }
 135
 136 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
 137                            int *slen)
 138 {
 139     int avail, rc;
 140     size_t src_len;
 141     uint8_t *to;
 142     OprtnsCommand *oc = (OprtnsCommand *) evt_buf_hdr;
 143
 144     if (!event->event_pending) {
 145         /* no data pending */
 146         return 0;
 147     }
 148
 149     to = (uint8_t *)&oc->data;
 150     avail = *slen - sizeof(OprtnsCommand);
 151     rc = get_console_data(event, to, &src_len, avail);
 152     if (rc) {
 153         /* data didn't fit, try next SCCB */
 154         return 1;
 155     }
 156
 157     oc->message_unit.mdmsu.gds_id = GDS_ID_MDSMU;
 158     oc->message_unit.mdmsu.length = cpu_to_be16(sizeof(struct MDMSU));
 159
 160     oc->message_unit.cpmsu.gds_id = GDS_ID_CPMSU;
 161     oc->message_unit.cpmsu.length =
 162         cpu_to_be16(sizeof(struct MDMSU) - sizeof(GdsVector));
 163
 164     oc->message_unit.text_command.gds_id = GDS_ID_TEXTCMD;
 165     oc->message_unit.text_command.length =
 166         cpu_to_be16(sizeof(struct MDMSU) - (2 * sizeof(GdsVector)));
 167
 168     oc->message_unit.self_def_text_message.key = GDS_KEY_SELFDEFTEXTMSG;
 169     oc->message_unit.self_def_text_message.length =
 170         cpu_to_be16(sizeof(struct MDMSU) - (3 * sizeof(GdsVector)));
 171
 172     oc->message_unit.text_message.key = GDS_KEY_TEXTMSG;
 173     oc->message_unit.text_message.length =
 174         cpu_to_be16(sizeof(GdsSubvector) + src_len);
 175
 176     oc->header.length = cpu_to_be16(sizeof(OprtnsCommand) + src_len);
 177     oc->header.type = SCLP_EVENT_OPRTNS_COMMAND;
 178     *slen = avail - src_len;
 179
 180     return 1;
 181 }
 182
 183 /*
 184  * Triggered by SCLP's write_event_data
 185  *  - write console data to character layer
 186  *  returns < 0 if an error occurred
 187  */
 188 static int write_console_data(SCLPEvent *event, const uint8_t *buf, int len)
 189 {
 190     int ret = 0;
 191     const uint8_t *buf_offset;
 192
 193     SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
 194
 195     if (!scon->chr) {
 196         /* If there's no backend, we can just say we consumed all data. */
 197         return len;
 198     }
 199
 200     buf_offset = buf;
 201     while (len > 0) {
 202         ret = qemu_chr_fe_write(scon->chr, buf, len);
 203         if (ret == 0) {
 204             /* a pty doesn't seem to be connected - no error */
 205             len = 0;
 206         } else if (ret == -EAGAIN || (ret > 0 && ret < len)) {
 207             len -= ret;
 208             buf_offset += ret;
 209         } else {
 210             len = 0;
 211         }
 212     }
 213
 214     return ret;
 215 }
 216
 217 static int process_mdb(SCLPEvent *event, MDBO *mdbo)
 218 {
 219     int rc;
 220     int len;
 221     uint8_t buffer[SIZE_BUFFER];
 222
 223     len = be16_to_cpu(mdbo->length);
 224     len -= sizeof(mdbo->length) + sizeof(mdbo->type)
 225             + sizeof(mdbo->mto.line_type_flags)
 226             + sizeof(mdbo->mto.alarm_control)
 227             + sizeof(mdbo->mto._reserved);
 228
 229     assert(len <= SIZE_BUFFER);
 230
 231     /* convert EBCDIC SCLP contents to ASCII console message */
 232     ascii_put(buffer, mdbo->mto.message, len);
 233     rc = write_console_data(event, (uint8_t *)NEWLINE, 1);
 234     if (rc < 0) {
 235         return rc;
 236     }
 237     return write_console_data(event, buffer, len);
 238 }
 239
 240 static int write_event_data(SCLPEvent *event, EventBufferHeader *ebh)
 241 {
 242     int len;
 243     int written;
 244     int errors = 0;
 245     MDBO *mdbo;
 246     SclpMsg *data = (SclpMsg *) ebh;
 247     SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
 248
 249     len = be16_to_cpu(data->mdb.header.length);
 250     if (len < sizeof(data->mdb.header)) {
 251         return SCLP_RC_INCONSISTENT_LENGTHS;
 252     }
 253     len -= sizeof(data->mdb.header);
 254
 255     /* first check message buffers */
 256     mdbo = data->mdb.mdbo;
 257     while (len > 0) {
 258         if (be16_to_cpu(mdbo->length) > len
 259                 || be16_to_cpu(mdbo->length) == 0) {
 260             return SCLP_RC_INCONSISTENT_LENGTHS;
 261         }
 262         len -= be16_to_cpu(mdbo->length);
 263         mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
 264     }
 265
 266     /* then execute */
 267     len = be16_to_cpu(data->mdb.header.length) - sizeof(data->mdb.header);
 268     mdbo = data->mdb.mdbo;
 269     while (len > 0) {
 270         switch (be16_to_cpu(mdbo->type)) {
 271         case MESSAGE_TEXT:
 272             /* message text object */
 273             written = process_mdb(event, mdbo);
 274             if (written < 0) {
 275                 /* character layer error */
 276                 errors++;
 277             }
 278             break;
 279         default: /* ignore */
 280             break;
 281         }
 282         len -= be16_to_cpu(mdbo->length);
 283         mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
 284     }
 285     if (errors) {
 286         scon->write_errors += errors;
 287     }
 288     data->header.flags = SCLP_EVENT_BUFFER_ACCEPTED;
 289
 290     return SCLP_RC_NORMAL_COMPLETION;
 291 }
 292
 293 /* functions for live migration */
 294
 295 static const VMStateDescription vmstate_sclplmconsole = {
 296     .name = "sclplmconsole",
 297     .version_id = 0,
 298     .minimum_version_id = 0,
 299     .fields = (VMStateField[]) {
 300         VMSTATE_BOOL(event.event_pending, SCLPConsoleLM),
 301         VMSTATE_UINT32(write_errors, SCLPConsoleLM),
 302         VMSTATE_UINT32(length, SCLPConsoleLM),
 303         VMSTATE_UINT8_ARRAY(buf, SCLPConsoleLM, SIZE_CONSOLE_BUFFER),
 304         VMSTATE_END_OF_LIST()
 305      }
 306 };
 307
 308 /* qemu object creation and initialization functions */
 309
 310 /* tell character layer our call-back functions */
 311
 312 static int console_init(SCLPEvent *event)
 313 {
 314     static bool console_available;
 315
 316     SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
 317
 318     if (console_available) {
 319         error_report("Multiple line-mode operator consoles are not supported");
 320         return -1;
 321     }
 322     console_available = true;
 323
 324     if (scon->chr) {
 325         qemu_chr_add_handlers(scon->chr, chr_can_read, chr_read, NULL, scon);
 326     }
 327
 328     return 0;
 329 }
 330
 331 static int console_exit(SCLPEvent *event)
 332 {
 333     return 0;
 334 }
 335
 336 static void console_reset(DeviceState *dev)
 337 {
 338    SCLPEvent *event = SCLP_EVENT(dev);
 339    SCLPConsoleLM *scon = DO_UPCAST(SCLPConsoleLM, event, event);
 340
 341    event->event_pending = false;
 342    scon->length = 0;
 343    scon->write_errors = 0;
 344 }
 345
 346 static Property console_properties[] = {
 347     DEFINE_PROP_CHR("chardev", SCLPConsoleLM, chr),
 348     DEFINE_PROP_UINT32("write_errors", SCLPConsoleLM, write_errors, 0),
 349     DEFINE_PROP_BOOL("echo", SCLPConsoleLM, echo, true),
 350     DEFINE_PROP_END_OF_LIST(),
 351 };
 352
 353 static void console_class_init(ObjectClass *klass, void *data)
 354 {
 355     DeviceClass *dc = DEVICE_CLASS(klass);
 356     SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
 357
 358     dc->props = console_properties;
 359     dc->reset = console_reset;
 360     dc->vmsd = &vmstate_sclplmconsole;
 361     ec->init = console_init;
 362     ec->exit = console_exit;
 363     ec->get_send_mask = send_mask;
 364     ec->get_receive_mask = receive_mask;
 365     ec->can_handle_event = can_handle_event;
 366     ec->read_event_data = read_event_data;
 367     ec->write_event_data = write_event_data;
 368     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 369 }
 370
 371 static const TypeInfo sclp_console_info = {
 372     .name          = "sclplmconsole",
 373     .parent        = TYPE_SCLP_EVENT,
 374     .instance_size = sizeof(SCLPConsoleLM),
 375     .class_init    = console_class_init,
 376     .class_size    = sizeof(SCLPEventClass),
 377 };
 378
 379 static void register_types(void)
 380 {
 381     type_register_static(&sclp_console_info);
 382 }
 383
 384 type_init(register_types)