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