LXR qemu/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
  33typedef 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
  42struct 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};
  50typedef struct SCLPConsoleLM SCLPConsoleLM;
  51
  52#define TYPE_SCLPLM_CONSOLE "sclplmconsole"
  53DECLARE_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
  69static 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
  79static 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
 105static bool can_handle_event(uint8_t type)
 106{
 107    return type == SCLP_EVENT_MESSAGE || type == SCLP_EVENT_PMSGCMD;
 108}
 109
 110static sccb_mask_t send_mask(void)
 111{
 112    return SCLP_EVENT_MASK_OP_CMD | SCLP_EVENT_MASK_PMSGCMD;
 113}
 114
 115static 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 */
 125static 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
 147static 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 */
 199static 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
 213static 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
 236static 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
 291static const VMStateDescription vmstate_sclplmconsole = {
 292    .name = "sclplmconsole",
 293    .version_id = 0,
 294    .minimum_version_id = 0,
 295    .fields = (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
 308static 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
 326static 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
 336static 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
 343static 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
 360static 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
 368static void register_types(void)
 369{
 370    type_register_static(&sclp_console_info);
 371}
 372
 373type_init(register_types)
 374