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