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