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/s390x/ebcdic.h"
  27
  28#define SIZE_BUFFER 4096
  29#define NEWLINE     "\n"
  30
  31typedef struct OprtnsCommand {
  32    EventBufferHeader header;
  33    MDMSU message_unit;
  34    char data[0];
  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
  40typedef 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
  66static 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
  76static 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
 102static bool can_handle_event(uint8_t type)
 103{
 104    return type == SCLP_EVENT_MESSAGE || type == SCLP_EVENT_PMSGCMD;
 105}
 106
 107static sccb_mask_t send_mask(void)
 108{
 109    return SCLP_EVENT_MASK_OP_CMD | SCLP_EVENT_MASK_PMSGCMD;
 110}
 111
 112static 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 */
 122static 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
 144static 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 */
 196static 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
 210static 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
 233static 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
 288static 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
 305static 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
 323static 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
 333static 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
 340static void console_class_init(ObjectClass *klass, void *data)
 341{
 342    DeviceClass *dc = DEVICE_CLASS(klass);
 343    SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
 344
 345    dc->props = 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
 357static const TypeInfo sclp_console_info = {
 358    .name          = "sclplmconsole",
 359    .parent        = TYPE_SCLP_EVENT,
 360    .instance_size = sizeof(SCLPConsoleLM),
 361    .class_init    = console_class_init,
 362    .class_size    = sizeof(SCLPEventClass),
 363};
 364
 365static void register_types(void)
 366{
 367    type_register_static(&sclp_console_info);
 368}
 369
 370type_init(register_types)
 371