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 "hw/qdev.h"
  18#include "qemu/thread.h"
  19#include "qemu/error-report.h"
  20#include "chardev/char-fe.h"
  21
  22#include "hw/s390x/sclp.h"
  23#include "hw/s390x/event-facility.h"
  24#include "hw/s390x/ebcdic.h"
  25
  26#define SIZE_BUFFER 4096
  27#define NEWLINE     "\n"
  28
  29typedef struct OprtnsCommand {
  30    EventBufferHeader header;
  31    MDMSU message_unit;
  32    char data[0];
  33} QEMU_PACKED OprtnsCommand;
  34
  35/* max size for line-mode data in 4K SCCB page */
  36#define SIZE_CONSOLE_BUFFER (SCCB_DATA_LEN - sizeof(OprtnsCommand))
  37
  38typedef struct SCLPConsoleLM {
  39    SCLPEvent event;
  40    CharBackend chr;
  41    bool echo;                  /* immediate echo of input if true        */
  42    uint32_t write_errors;      /* errors writing to char layer           */
  43    uint32_t length;            /* length of byte stream in buffer        */
  44    uint8_t buf[SIZE_CONSOLE_BUFFER];
  45} SCLPConsoleLM;
  46
  47#define TYPE_SCLPLM_CONSOLE "sclplmconsole"
  48#define SCLPLM_CONSOLE(obj) \
  49    OBJECT_CHECK(SCLPConsoleLM, (obj), TYPE_SCLPLM_CONSOLE)
  50
  51/*
  52*  Character layer call-back functions
  53 *
  54 * Allow 1 character at a time
  55 *
  56 * Accumulate bytes from character layer in console buffer,
  57 * event_pending is set when a newline character is encountered
  58 *
  59 * The maximum command line length is limited by the maximum
  60 * space available in an SCCB. Line mode console input is sent
  61 * truncated to the guest in case it doesn't fit into the SCCB.
  62 */
  63
  64static int chr_can_read(void *opaque)
  65{
  66    SCLPConsoleLM *scon = opaque;
  67
  68    if (scon->event.event_pending) {
  69        return 0;
  70    }
  71    return 1;
  72}
  73
  74static void chr_read(void *opaque, const uint8_t *buf, int size)
  75{
  76    SCLPConsoleLM *scon = opaque;
  77
  78    assert(size == 1);
  79
  80    if (*buf == '\r' || *buf == '\n') {
  81        scon->event.event_pending = true;
  82        sclp_service_interrupt(0);
  83        return;
  84    }
  85    if (scon->length == SIZE_CONSOLE_BUFFER) {
  86        /* Eat the character, but still process CR and LF.  */
  87        return;
  88    }
  89    scon->buf[scon->length] = *buf;
  90    scon->length += 1;
  91    if (scon->echo) {
  92        /* XXX this blocks entire thread. Rewrite to use
  93         * qemu_chr_fe_write and background I/O callbacks */
  94        qemu_chr_fe_write_all(&scon->chr, buf, size);
  95    }
  96}
  97
  98/* functions to be called by event facility */
  99
 100static bool can_handle_event(uint8_t type)
 101{
 102    return type == SCLP_EVENT_MESSAGE || type == SCLP_EVENT_PMSGCMD;
 103}
 104
 105static sccb_mask_t send_mask(void)
 106{
 107    return SCLP_EVENT_MASK_OP_CMD | SCLP_EVENT_MASK_PMSGCMD;
 108}
 109
 110static sccb_mask_t receive_mask(void)
 111{
 112    return SCLP_EVENT_MASK_MSG | SCLP_EVENT_MASK_PMSGCMD;
 113}
 114
 115/*
 116 * Triggered by SCLP's read_event_data
 117 * - convert ASCII byte stream to EBCDIC and
 118 * - copy converted data into provided (SCLP) buffer
 119 */
 120static int get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
 121                            int avail)
 122{
 123    int len;
 124
 125    SCLPConsoleLM *cons = SCLPLM_CONSOLE(event);
 126
 127    len = cons->length;
 128    /* data need to fit into provided SCLP buffer */
 129    if (len > avail) {
 130        return 1;
 131    }
 132
 133    ebcdic_put(buf, (char *)&cons->buf, len);
 134    *size = len;
 135    cons->length = 0;
 136    /* data provided and no more data pending */
 137    event->event_pending = false;
 138    qemu_notify_event();
 139    return 0;
 140}
 141
 142static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
 143                           int *slen)
 144{
 145    int avail, rc;
 146    size_t src_len;
 147    uint8_t *to;
 148    OprtnsCommand *oc = (OprtnsCommand *) evt_buf_hdr;
 149
 150    if (!event->event_pending) {
 151        /* no data pending */
 152        return 0;
 153    }
 154
 155    to = (uint8_t *)&oc->data;
 156    avail = *slen - sizeof(OprtnsCommand);
 157    rc = get_console_data(event, to, &src_len, avail);
 158    if (rc) {
 159        /* data didn't fit, try next SCCB */
 160        return 1;
 161    }
 162
 163    oc->message_unit.mdmsu.gds_id = GDS_ID_MDSMU;
 164    oc->message_unit.mdmsu.length = cpu_to_be16(sizeof(struct MDMSU));
 165
 166    oc->message_unit.cpmsu.gds_id = GDS_ID_CPMSU;
 167    oc->message_unit.cpmsu.length =
 168        cpu_to_be16(sizeof(struct MDMSU) - sizeof(GdsVector));
 169
 170    oc->message_unit.text_command.gds_id = GDS_ID_TEXTCMD;
 171    oc->message_unit.text_command.length =
 172        cpu_to_be16(sizeof(struct MDMSU) - (2 * sizeof(GdsVector)));
 173
 174    oc->message_unit.self_def_text_message.key = GDS_KEY_SELFDEFTEXTMSG;
 175    oc->message_unit.self_def_text_message.length =
 176        cpu_to_be16(sizeof(struct MDMSU) - (3 * sizeof(GdsVector)));
 177
 178    oc->message_unit.text_message.key = GDS_KEY_TEXTMSG;
 179    oc->message_unit.text_message.length =
 180        cpu_to_be16(sizeof(GdsSubvector) + src_len);
 181
 182    oc->header.length = cpu_to_be16(sizeof(OprtnsCommand) + src_len);
 183    oc->header.type = SCLP_EVENT_OPRTNS_COMMAND;
 184    *slen = avail - src_len;
 185
 186    return 1;
 187}
 188
 189/*
 190 * Triggered by SCLP's write_event_data
 191 *  - write console data to character layer
 192 *  returns < 0 if an error occurred
 193 */
 194static int write_console_data(SCLPEvent *event, const uint8_t *buf, int len)
 195{
 196    SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
 197
 198    if (!qemu_chr_fe_backend_connected(&scon->chr)) {
 199        /* If there's no backend, we can just say we consumed all data. */
 200        return len;
 201    }
 202
 203    /* XXX this blocks entire thread. Rewrite to use
 204     * qemu_chr_fe_write and background I/O callbacks */
 205    return qemu_chr_fe_write_all(&scon->chr, buf, len);
 206}
 207
 208static int process_mdb(SCLPEvent *event, MDBO *mdbo)
 209{
 210    int rc;
 211    int len;
 212    uint8_t buffer[SIZE_BUFFER];
 213
 214    len = be16_to_cpu(mdbo->length);
 215    len -= sizeof(mdbo->length) + sizeof(mdbo->type)
 216            + sizeof(mdbo->mto.line_type_flags)
 217            + sizeof(mdbo->mto.alarm_control)
 218            + sizeof(mdbo->mto._reserved);
 219
 220    assert(len <= SIZE_BUFFER);
 221
 222    /* convert EBCDIC SCLP contents to ASCII console message */
 223    ascii_put(buffer, mdbo->mto.message, len);
 224    rc = write_console_data(event, (uint8_t *)NEWLINE, 1);
 225    if (rc < 0) {
 226        return rc;
 227    }
 228    return write_console_data(event, buffer, len);
 229}
 230
 231static int write_event_data(SCLPEvent *event, EventBufferHeader *ebh)
 232{
 233    int len;
 234    int written;
 235    int errors = 0;
 236    MDBO *mdbo;
 237    SclpMsg *data = (SclpMsg *) ebh;
 238    SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
 239
 240    len = be16_to_cpu(data->mdb.header.length);
 241    if (len < sizeof(data->mdb.header)) {
 242        return SCLP_RC_INCONSISTENT_LENGTHS;
 243    }
 244    len -= sizeof(data->mdb.header);
 245
 246    /* first check message buffers */
 247    mdbo = data->mdb.mdbo;
 248    while (len > 0) {
 249        if (be16_to_cpu(mdbo->length) > len
 250                || be16_to_cpu(mdbo->length) == 0) {
 251            return SCLP_RC_INCONSISTENT_LENGTHS;
 252        }
 253        len -= be16_to_cpu(mdbo->length);
 254        mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
 255    }
 256
 257    /* then execute */
 258    len = be16_to_cpu(data->mdb.header.length) - sizeof(data->mdb.header);
 259    mdbo = data->mdb.mdbo;
 260    while (len > 0) {
 261        switch (be16_to_cpu(mdbo->type)) {
 262        case MESSAGE_TEXT:
 263            /* message text object */
 264            written = process_mdb(event, mdbo);
 265            if (written < 0) {
 266                /* character layer error */
 267                errors++;
 268            }
 269            break;
 270        default: /* ignore */
 271            break;
 272        }
 273        len -= be16_to_cpu(mdbo->length);
 274        mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
 275    }
 276    if (errors) {
 277        scon->write_errors += errors;
 278    }
 279    data->header.flags = SCLP_EVENT_BUFFER_ACCEPTED;
 280
 281    return SCLP_RC_NORMAL_COMPLETION;
 282}
 283
 284/* functions for live migration */
 285
 286static const VMStateDescription vmstate_sclplmconsole = {
 287    .name = "sclplmconsole",
 288    .version_id = 0,
 289    .minimum_version_id = 0,
 290    .fields = (VMStateField[]) {
 291        VMSTATE_BOOL(event.event_pending, SCLPConsoleLM),
 292        VMSTATE_UINT32(write_errors, SCLPConsoleLM),
 293        VMSTATE_UINT32(length, SCLPConsoleLM),
 294        VMSTATE_UINT8_ARRAY(buf, SCLPConsoleLM, SIZE_CONSOLE_BUFFER),
 295        VMSTATE_END_OF_LIST()
 296     }
 297};
 298
 299/* qemu object creation and initialization functions */
 300
 301/* tell character layer our call-back functions */
 302
 303static int console_init(SCLPEvent *event)
 304{
 305    static bool console_available;
 306
 307    SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
 308
 309    if (console_available) {
 310        error_report("Multiple line-mode operator consoles are not supported");
 311        return -1;
 312    }
 313    console_available = true;
 314
 315    qemu_chr_fe_set_handlers(&scon->chr, chr_can_read,
 316                             chr_read, NULL, NULL, scon, NULL, true);
 317
 318    return 0;
 319}
 320
 321static void console_reset(DeviceState *dev)
 322{
 323   SCLPEvent *event = SCLP_EVENT(dev);
 324   SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
 325
 326   event->event_pending = false;
 327   scon->length = 0;
 328   scon->write_errors = 0;
 329}
 330
 331static Property console_properties[] = {
 332    DEFINE_PROP_CHR("chardev", SCLPConsoleLM, chr),
 333    DEFINE_PROP_UINT32("write_errors", SCLPConsoleLM, write_errors, 0),
 334    DEFINE_PROP_BOOL("echo", SCLPConsoleLM, echo, true),
 335    DEFINE_PROP_END_OF_LIST(),
 336};
 337
 338static void console_class_init(ObjectClass *klass, void *data)
 339{
 340    DeviceClass *dc = DEVICE_CLASS(klass);
 341    SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
 342
 343    dc->props = console_properties;
 344    dc->reset = console_reset;
 345    dc->vmsd = &vmstate_sclplmconsole;
 346    ec->init = console_init;
 347    ec->get_send_mask = send_mask;
 348    ec->get_receive_mask = receive_mask;
 349    ec->can_handle_event = can_handle_event;
 350    ec->read_event_data = read_event_data;
 351    ec->write_event_data = write_event_data;
 352    set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 353}
 354
 355static const TypeInfo sclp_console_info = {
 356    .name          = "sclplmconsole",
 357    .parent        = TYPE_SCLP_EVENT,
 358    .instance_size = sizeof(SCLPConsoleLM),
 359    .class_init    = console_class_init,
 360    .class_size    = sizeof(SCLPEventClass),
 361};
 362
 363static void register_types(void)
 364{
 365    type_register_static(&sclp_console_info);
 366}
 367
 368type_init(register_types)
 369