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