hw/char/sclpconsole.c

   1 /*
   2  * SCLP event type
   3  *    Ascii Console Data (VT220 Console)
   4  *
   5  * Copyright IBM, Corp. 2012
   6  *
   7  * Authors:
   8  *  Heinz Graalfs <graalfs@de.ibm.com>
   9  *
  10  * This work is licensed under the terms of the GNU GPL, version 2 or (at your
  11  * option) any later version.  See the COPYING file in the top-level directory.
  12  *
  13  */
  14
  15 #include "qemu/osdep.h"
  16 #include "qemu/thread.h"
  17 #include "qemu/error-report.h"
  18 #include "qemu/module.h"
  19
  20 #include "hw/s390x/sclp.h"
  21 #include "migration/vmstate.h"
  22 #include "hw/qdev-properties.h"
  23 #include "hw/qdev-properties-system.h"
  24 #include "hw/s390x/event-facility.h"
  25 #include "chardev/char-fe.h"
  26 #include "qom/object.h"
  27
  28 typedef struct ASCIIConsoleData {
  29     EventBufferHeader ebh;
  30     char data[];
  31 } QEMU_PACKED ASCIIConsoleData;
  32
  33 /* max size for ASCII data in 4K SCCB page */
  34 #define SIZE_BUFFER_VT220 4080
  35
  36 struct SCLPConsole {
  37     SCLPEvent event;
  38     CharBackend chr;
  39     uint8_t iov[SIZE_BUFFER_VT220];
  40     uint32_t iov_sclp;      /* offset in buf for SCLP read operation       */
  41     uint32_t iov_bs;        /* offset in buf for char layer read operation */
  42     uint32_t iov_data_len;  /* length of byte stream in buffer             */
  43     uint32_t iov_sclp_rest; /* length of byte stream not read via SCLP     */
  44     bool notify;            /* qemu_notify_event() req'd if true           */
  45 };
  46 typedef struct SCLPConsole SCLPConsole;
  47
  48 #define TYPE_SCLP_CONSOLE "sclpconsole"
  49 DECLARE_INSTANCE_CHECKER(SCLPConsole, SCLP_CONSOLE,
  50                          TYPE_SCLP_CONSOLE)
  51
  52 /* character layer call-back functions */
  53
  54 /* Return number of bytes that fit into iov buffer */
  55 static int chr_can_read(void *opaque)
  56 {
  57     SCLPConsole *scon = opaque;
  58     int avail = SIZE_BUFFER_VT220 - scon->iov_data_len;
  59
  60     if (avail == 0) {
  61         scon->notify = true;
  62     }
  63     return avail;
  64 }
  65
  66 /* Send data from a char device over to the guest */
  67 static void chr_read(void *opaque, const uint8_t *buf, int size)
  68 {
  69     SCLPConsole *scon = opaque;
  70
  71     assert(scon);
  72     /* read data must fit into current buffer */
  73     assert(size <= SIZE_BUFFER_VT220 - scon->iov_data_len);
  74
  75     /* put byte-stream from character layer into buffer */
  76     memcpy(&scon->iov[scon->iov_bs], buf, size);
  77     scon->iov_data_len += size;
  78     scon->iov_sclp_rest += size;
  79     scon->iov_bs += size;
  80     scon->event.event_pending = true;
  81     sclp_service_interrupt(0);
  82 }
  83
  84 /* functions to be called by event facility */
  85
  86 static bool can_handle_event(uint8_t type)
  87 {
  88     return type == SCLP_EVENT_ASCII_CONSOLE_DATA;
  89 }
  90
  91 static sccb_mask_t send_mask(void)
  92 {
  93     return SCLP_EVENT_MASK_MSG_ASCII;
  94 }
  95
  96 static sccb_mask_t receive_mask(void)
  97 {
  98     return SCLP_EVENT_MASK_MSG_ASCII;
  99 }
 100
 101 /* triggered by SCLP's read_event_data -
 102  * copy console data byte-stream into provided (SCLP) buffer
 103  */
 104 static void get_console_data(SCLPEvent *event, uint8_t *buf, size_t *size,
 105                              int avail)
 106 {
 107     SCLPConsole *cons = SCLP_CONSOLE(event);
 108
 109     /* first byte is hex 0 saying an ascii string follows */
 110     *buf++ = '\0';
 111     avail--;
 112     /* if all data fit into provided SCLP buffer */
 113     if (avail >= cons->iov_sclp_rest) {
 114         /* copy character byte-stream to SCLP buffer */
 115         memcpy(buf, &cons->iov[cons->iov_sclp], cons->iov_sclp_rest);
 116         *size = cons->iov_sclp_rest + 1;
 117         cons->iov_sclp = 0;
 118         cons->iov_bs = 0;
 119         cons->iov_data_len = 0;
 120         cons->iov_sclp_rest = 0;
 121         event->event_pending = false;
 122         /* data provided and no more data pending */
 123     } else {
 124         /* if provided buffer is too small, just copy part */
 125         memcpy(buf, &cons->iov[cons->iov_sclp], avail);
 126         *size = avail + 1;
 127         cons->iov_sclp_rest -= avail;
 128         cons->iov_sclp += avail;
 129         /* more data pending */
 130     }
 131     if (cons->notify) {
 132         cons->notify = false;
 133         qemu_notify_event();
 134     }
 135 }
 136
 137 static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
 138                            int *slen)
 139 {
 140     int avail;
 141     size_t src_len;
 142     uint8_t *to;
 143     ASCIIConsoleData *acd = (ASCIIConsoleData *) evt_buf_hdr;
 144
 145     if (!event->event_pending) {
 146         /* no data pending */
 147         return 0;
 148     }
 149
 150     to = (uint8_t *)&acd->data;
 151     avail = *slen - sizeof(ASCIIConsoleData);
 152     get_console_data(event, to, &src_len, avail);
 153
 154     acd->ebh.length = cpu_to_be16(sizeof(ASCIIConsoleData) + src_len);
 155     acd->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
 156     acd->ebh.flags |= SCLP_EVENT_BUFFER_ACCEPTED;
 157     *slen = avail - src_len;
 158
 159     return 1;
 160 }
 161
 162 /* triggered by SCLP's write_event_data
 163  *  - write console data to character layer
 164  *  returns < 0 if an error occurred
 165  */
 166 static ssize_t write_console_data(SCLPEvent *event, const uint8_t *buf,
 167                                   size_t len)
 168 {
 169     SCLPConsole *scon = SCLP_CONSOLE(event);
 170
 171     if (!qemu_chr_fe_backend_connected(&scon->chr)) {
 172         /* If there's no backend, we can just say we consumed all data. */
 173         return len;
 174     }
 175
 176     /* XXX this blocks entire thread. Rewrite to use
 177      * qemu_chr_fe_write and background I/O callbacks */
 178     return qemu_chr_fe_write_all(&scon->chr, buf, len);
 179 }
 180
 181 static int write_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr)
 182 {
 183     int rc;
 184     int length;
 185     ssize_t written;
 186     ASCIIConsoleData *acd = (ASCIIConsoleData *) evt_buf_hdr;
 187
 188     length = be16_to_cpu(evt_buf_hdr->length) - sizeof(EventBufferHeader);
 189     written = write_console_data(event, (uint8_t *)acd->data, length);
 190
 191     rc = SCLP_RC_NORMAL_COMPLETION;
 192     /* set event buffer accepted flag */
 193     evt_buf_hdr->flags |= SCLP_EVENT_BUFFER_ACCEPTED;
 194
 195     /* written will be zero if a pty is not connected - don't treat as error */
 196     if (written < 0) {
 197         /* event buffer not accepted due to error in character layer */
 198         evt_buf_hdr->flags &= ~(SCLP_EVENT_BUFFER_ACCEPTED);
 199         rc = SCLP_RC_CONTAINED_EQUIPMENT_CHECK;
 200     }
 201
 202     return rc;
 203 }
 204
 205 static const VMStateDescription vmstate_sclpconsole = {
 206     .name = "sclpconsole",
 207     .version_id = 0,
 208     .minimum_version_id = 0,
 209     .fields = (VMStateField[]) {
 210         VMSTATE_BOOL(event.event_pending, SCLPConsole),
 211         VMSTATE_UINT8_ARRAY(iov, SCLPConsole, SIZE_BUFFER_VT220),
 212         VMSTATE_UINT32(iov_sclp, SCLPConsole),
 213         VMSTATE_UINT32(iov_bs, SCLPConsole),
 214         VMSTATE_UINT32(iov_data_len, SCLPConsole),
 215         VMSTATE_UINT32(iov_sclp_rest, SCLPConsole),
 216         VMSTATE_END_OF_LIST()
 217      }
 218 };
 219
 220 /* qemu object creation and initialization functions */
 221
 222 /* tell character layer our call-back functions */
 223
 224 static int console_init(SCLPEvent *event)
 225 {
 226     static bool console_available;
 227
 228     SCLPConsole *scon = SCLP_CONSOLE(event);
 229
 230     if (console_available) {
 231         error_report("Multiple VT220 operator consoles are not supported");
 232         return -1;
 233     }
 234     console_available = true;
 235     qemu_chr_fe_set_handlers(&scon->chr, chr_can_read,
 236                              chr_read, NULL, NULL, scon, NULL, true);
 237
 238     return 0;
 239 }
 240
 241 static void console_reset(DeviceState *dev)
 242 {
 243    SCLPEvent *event = SCLP_EVENT(dev);
 244    SCLPConsole *scon = SCLP_CONSOLE(event);
 245
 246    event->event_pending = false;
 247    scon->iov_sclp = 0;
 248    scon->iov_bs = 0;
 249    scon->iov_data_len = 0;
 250    scon->iov_sclp_rest = 0;
 251    scon->notify = false;
 252 }
 253
 254 static Property console_properties[] = {
 255     DEFINE_PROP_CHR("chardev", SCLPConsole, chr),
 256     DEFINE_PROP_END_OF_LIST(),
 257 };
 258
 259 static void console_class_init(ObjectClass *klass, void *data)
 260 {
 261     DeviceClass *dc = DEVICE_CLASS(klass);
 262     SCLPEventClass *ec = SCLP_EVENT_CLASS(klass);
 263
 264     device_class_set_props(dc, console_properties);
 265     dc->reset = console_reset;
 266     dc->vmsd = &vmstate_sclpconsole;
 267     ec->init = console_init;
 268     ec->get_send_mask = send_mask;
 269     ec->get_receive_mask = receive_mask;
 270     ec->can_handle_event = can_handle_event;
 271     ec->read_event_data = read_event_data;
 272     ec->write_event_data = write_event_data;
 273     set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
 274 }
 275
 276 static const TypeInfo sclp_console_info = {
 277     .name          = TYPE_SCLP_CONSOLE,
 278     .parent        = TYPE_SCLP_EVENT,
 279     .instance_size = sizeof(SCLPConsole),
 280     .class_init    = console_class_init,
 281     .class_size    = sizeof(SCLPEventClass),
 282 };
 283
 284 static void register_types(void)
 285 {
 286     type_register_static(&sclp_console_info);
 287 }
 288
 289 type_init(register_types)