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