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