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 "qemu/module.h"
  21#include "chardev/char-fe.h"
  22
  23#include "hw/s390x/sclp.h"
  24#include "hw/s390x/event-facility.h"
  25#include "hw/s390x/ebcdic.h"
  26
  27#define SIZE_BUFFER 4096
  28#define NEWLINE     "\n"
  29
  30typedef struct OprtnsCommand {
  31    EventBufferHeader header;
  32    MDMSU message_unit;
  33    char data[0];
  34} QEMU_PACKED OprtnsCommand;
  35
  36/* max size for line-mode data in 4K SCCB page */
  37#define SIZE_CONSOLE_BUFFER (SCCB_DATA_LEN - sizeof(OprtnsCommand))
  38
  39typedef struct SCLPConsoleLM {
  40    SCLPEvent event;
  41    CharBackend chr;
  42    bool echo;                  /* immediate echo of input if true        */
  43    uint32_t write_errors;      /* errors writing to char layer           */
  44    uint32_t length;            /* length of byte stream in buffer        */
  45    uint8_t buf[SIZE_CONSOLE_BUFFER];
  46} SCLPConsoleLM;
  47
  48#define TYPE_SCLPLM_CONSOLE "sclplmconsole"
  49#define SCLPLM_CONSOLE(obj) \
  50    OBJECT_CHECK(SCLPConsoleLM, (obj), TYPE_SCLPLM_CONSOLE)
  51
  52/*
  53*  Character layer call-back functions
  54 *
  55 * Allow 1 character at a time
  56 *
  57 * Accumulate bytes from character layer in console buffer,
  58 * event_pending is set when a newline character is encountered
  59 *
  60 * The maximum command line length is limited by the maximum
  61 * space available in an SCCB. Line mode console input is sent
  62 * truncated to the guest in case it doesn't fit into the SCCB.
  63 */
  64
  65static int chr_can_read(void *opaque)
  66{
  67    SCLPConsoleLM *scon = opaque;
  68
  69    if (scon->event.event_pending) {
  70        return 0;
  71    }
  72    return 1;
  73}
  74
  75static void chr_read(void *opaque, const uint8_t *buf, int size)
  76{
  77    SCLPConsoleLM *scon = opaque;
  78
  79    assert(size == 1);
  80
  81    if (*buf == '\r' || *buf == '\n') {
  82        scon->event.event_pending = true;
  83        sclp_service_interrupt(0);
  84        return;
  85    }
  86    if (scon->length == SIZE_CONSOLE_BUFFER) {
  87        /* Eat the character, but still process CR and LF.  */
  88        return;
  89    }
  90    scon->buf[scon->length] = *buf;
  91    scon->length += 1;
  92    if (scon->echo) {
  93        /* XXX this blocks entire thread. Rewrite to use
  94         * qemu_chr_fe_write and background I/O callbacks */
  95        qemu_chr_fe_write_all(&scon->chr, buf, size);
  96    }
  97}
  98
  99/* functions to be called by event facility */
 100
 101static bool can_handle_event(uint8_t type)
 102{
 103    return type == SCLP_EVENT_MESSAGE || type == SCLP_EVENT_PMSGCMD;
 104}
 105
 106static sccb_mask_t send_mask(void)
 107{
 108    return SCLP_EVENT_MASK_OP_CMD | SCLP_EVENT_MASK_PMSGCMD;
 109}
 110
 111static sccb_mask_t receive_mask(void)
 112{
 113    return SCLP_EVENT_MASK_MSG | SCLP_EVENT_MASK_PMSGCMD;
 114}
 115
 116/*
 117 * Triggered by SCLP's read_event_data
 118 * - convert ASCII byte stream to EBCDIC and
 119 * - copy converted data into provided (SCLP) buffer
 120 */
 121static int get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
 122                            int avail)
 123{
 124    int len;
 125
 126    SCLPConsoleLM *cons = SCLPLM_CONSOLE(event);
 127
 128    len = cons->length;
 129    /* data need to fit into provided SCLP buffer */
 130    if (len > avail) {
 131        return 1;
 132    }
 133
 134    ebcdic_put(buf, (char *)&cons->buf, len);
 135    *size = len;
 136    cons->length = 0;
 137    /* data provided and no more data pending */
 138    event->event_pending = false;
 139    qemu_notify_event();
 140    return 0;
 141}
 142
 143static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
 144                           int *slen)
 145{
 146    int avail, rc;
 147    size_t src_len;
 148    uint8_t *to;
 149    OprtnsCommand *oc = (OprtnsCommand *) evt_buf_hdr;
 150
 151    if (!event->event_pending) {
 152        /* no data pending */
 153        return 0;
 154    }
 155
 156    to = (uint8_t *)&oc->data;
 157    avail = *slen - sizeof(OprtnsCommand);
 158    rc = get_console_data(event, to, &src_len, avail);
 159    if (rc) {
 160        /* data didn't fit, try next SCCB */
 161        return 1;
 162    }
 163
 164    oc->message_unit.mdmsu.gds_id = GDS_ID_MDSMU;
 165    oc->message_unit.mdmsu.length = cpu_to_be16(sizeof(struct MDMSU));
 166
 167    oc->message_unit.cpmsu.gds_id = GDS_ID_CPMSU;
 168    oc->message_unit.cpmsu.length =
 169        cpu_to_be16(sizeof(struct MDMSU) - sizeof(GdsVector));
 170
 171    oc->message_unit.text_command.gds_id = GDS_ID_TEXTCMD;
 172    oc->message_unit.text_command.length =
 173        cpu_to_be16(sizeof(struct MDMSU) - (2 * sizeof(GdsVector)));
 174
 175    oc->message_unit.self_def_text_message.key = GDS_KEY_SELFDEFTEXTMSG;
 176    oc->message_unit.self_def_text_message.length =
 177        cpu_to_be16(sizeof(struct MDMSU) - (3 * sizeof(GdsVector)));
 178
 179    oc->message_unit.text_message.key = GDS_KEY_TEXTMSG;
 180    oc->message_unit.text_message.length =
 181        cpu_to_be16(sizeof(GdsSubvector) + src_len);
 182
 183    oc->header.length = cpu_to_be16(sizeof(OprtnsCommand) + src_len);
 184    oc->header.type = SCLP_EVENT_OPRTNS_COMMAND;
 185    *slen = avail - src_len;
 186
 187    return 1;
 188}
 189
 190/*
 191 * Triggered by SCLP's write_event_data
 192 *  - write console data to character layer
 193 *  returns < 0 if an error occurred
 194 */
 195static int write_console_data(SCLPEvent *event, const uint8_t *buf, int len)
 196{
 197    SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
 198
 199    if (!qemu_chr_fe_backend_connected(&scon->chr)) {
 200        /* If there's no backend, we can just say we consumed all data. */
 201        return len;
 202    }
 203
 204    /* XXX this blocks entire thread. Rewrite to use
 205     * qemu_chr_fe_write and background I/O callbacks */
 206    return qemu_chr_fe_write_all(&scon->chr, buf, len);
 207}
 208
 209static int process_mdb(SCLPEvent *event, MDBO *mdbo)
 210{
 211    int rc;
 212    int len;
 213    uint8_t buffer[SIZE_BUFFER];
 214
 215    len = be16_to_cpu(mdbo->length);
 216    len -= sizeof(mdbo->length) + sizeof(mdbo->type)
 217            + sizeof(mdbo->mto.line_type_flags)
 218            + sizeof(mdbo->mto.alarm_control)
 219            + sizeof(mdbo->mto._reserved);
 220
 221    assert(len <= SIZE_BUFFER);
 222
 223    /* convert EBCDIC SCLP contents to ASCII console message */
 224    ascii_put(buffer, mdbo->mto.message, len);
 225    rc = write_console_data(event, (uint8_t *)NEWLINE, 1);
 226    if (rc < 0) {
 227        return rc;
 228    }
 229    return write_console_data(event, buffer, len);
 230}
 231
 232static int write_event_data(SCLPEvent *event, EventBufferHeader *ebh)
 233{
 234    int len;
 235    int written;
 236    int errors = 0;
 237    MDBO *mdbo;
 238    SclpMsg *data = (SclpMsg *) ebh;
 239    SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
 240
 241    len = be16_to_cpu(data->mdb.header.length);
 242    if (len < sizeof(data->mdb.header)) {
 243        return SCLP_RC_INCONSISTENT_LENGTHS;
 244    }
 245    len -= sizeof(data->mdb.header);
 246
 247    /* first check message buffers */
 248    mdbo = data->mdb.mdbo;
 249    while (len > 0) {
 250        if (be16_to_cpu(mdbo->length) > len
 251                || be16_to_cpu(mdbo->length) == 0) {
 252            return SCLP_RC_INCONSISTENT_LENGTHS;
 253        }
 254        len -= be16_to_cpu(mdbo->length);
 255        mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
 256    }
 257
 258    /* then execute */
 259    len = be16_to_cpu(data->mdb.header.length) - sizeof(data->mdb.header);
 260    mdbo = data->mdb.mdbo;
 261    while (len > 0) {
 262        switch (be16_to_cpu(mdbo->type)) {
 263        case MESSAGE_TEXT:
 264            /* message text object */
 265            written = process_mdb(event, mdbo);
 266            if (written < 0) {
 267                /* character layer error */
 268                errors++;
 269            }
 270            break;
 271        default: /* ignore */
 272            break;
 273        }
 274        len -= be16_to_cpu(mdbo->length);
 275        mdbo = (void *) mdbo + be16_to_cpu(mdbo->length);
 276    }
 277    if (errors) {
 278        scon->write_errors += errors;
 279    }
 280    data->header.flags = SCLP_EVENT_BUFFER_ACCEPTED;
 281
 282    return SCLP_RC_NORMAL_COMPLETION;
 283}
 284
 285/* functions for live migration */
 286
 287static const VMStateDescription vmstate_sclplmconsole = {
 288    .name = "sclplmconsole",
 289    .version_id = 0,
 290    .minimum_version_id = 0,
 291    .fields = (VMStateField[]) {
 292        VMSTATE_BOOL(event.event_pending, SCLPConsoleLM),
 293        VMSTATE_UINT32(write_errors, SCLPConsoleLM),
 294        VMSTATE_UINT32(length, SCLPConsoleLM),
 295        VMSTATE_UINT8_ARRAY(buf, SCLPConsoleLM, SIZE_CONSOLE_BUFFER),
 296        VMSTATE_END_OF_LIST()
 297     }
 298};
 299
 300/* qemu object creation and initialization functions */
 301
 302/* tell character layer our call-back functions */
 303
 304static int console_init(SCLPEvent *event)
 305{
 306    static bool console_available;
 307
 308    SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
 309
 310    if (console_available) {
 311        error_report("Multiple line-mode operator consoles are not supported");
 312        return -1;
 313    }
 314    console_available = true;
 315
 316    qemu_chr_fe_set_handlers(&scon->chr, chr_can_read,
 317                             chr_read, NULL, NULL, scon, NULL, true);
 318
 319    return 0;
 320}
 321
 322static void console_reset(DeviceState *dev)
 323{
 324   SCLPEvent *event = SCLP_EVENT(dev);
 325   SCLPConsoleLM *scon = SCLPLM_CONSOLE(event);
 326
 327   event->event_pending = false;
 328   scon->length = 0;
 329   scon->write_errors = 0;
 330}
 331
 332static Property console_properties[] = {
 333    DEFINE_PROP_CHR("chardev", SCLPConsoleLM, chr),
 334    DEFINE_PROP_UINT32("write_errors", SCLPConsoleLM, write_errors, 0),
 335    DEFINE_PROP_BOOL("echo", SCLPConsoleLM, echo, true),
 336    DEFINE_PROP_END_OF_LIST(),
 337};
 338
 339static void console_class_init(ObjectClass *klass, void *data)
 340{
 341    DeviceClass *dc = DEVICE_CLASS(klass);
 342    SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
 343
 344    dc->props = console_properties;
 345    dc->reset = console_reset;
 346    dc->vmsd = &vmstate_sclplmconsole;
 347    ec->init = console_init;
 348    ec->get_send_mask = send_mask;
 349    ec->get_receive_mask = receive_mask;
 350    ec->can_handle_event = can_handle_event;
 351    ec->read_event_data = read_event_data;
 352    ec->write_event_data = write_event_data;
 353    set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 354}
 355
 356static const TypeInfo sclp_console_info = {
 357    .name          = "sclplmconsole",
 358    .parent        = TYPE_SCLP_EVENT,
 359    .instance_size = sizeof(SCLPConsoleLM),
 360    .class_init    = console_class_init,
 361    .class_size    = sizeof(SCLPEventClass),
 362};
 363
 364static void register_types(void)
 365{
 366    type_register_static(&sclp_console_info);
 367}
 368
 369type_init(register_types)
 370