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sclpconsole-lm.c (10461B)

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