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