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