1 /*
2 * SCLP
3 * Event Facility
4 * handles SCLP event types
5 * - Signal Quiesce - system power down
6 * - ASCII Console Data - VT220 read and write
7 * - Control-Program Identification - Send OS data from guest to host
8 *
9 * Copyright IBM, Corp. 2012
10 *
11 * Authors:
12 * Heinz Graalfs <graalfs@de.ibm.com>
13 *
14 * This work is licensed under the terms of the GNU GPL, version 2 or (at your
15 * option) any later version. See the COPYING file in the top-level directory.
16 *
17 */
18
19 #include "qemu/osdep.h"
20 #include "qapi/error.h"
21 #include "qemu/module.h"
22
23 #include "hw/s390x/sclp.h"
24 #include "migration/vmstate.h"
25 #include "hw/s390x/event-facility.h"
26
27 typedef struct SCLPEventsBus {
28 BusState qbus;
29 } SCLPEventsBus;
30
31 /* we need to save 32 bit chunks for compatibility */
32 #if HOST_BIG_ENDIAN
33 #define RECV_MASK_LOWER 1
34 #define RECV_MASK_UPPER 0
35 #else /* little endian host */
36 #define RECV_MASK_LOWER 0
37 #define RECV_MASK_UPPER 1
38 #endif
39
40 struct SCLPEventFacility {
41 SysBusDevice parent_obj;
42 SCLPEventsBus sbus;
43 SCLPEvent quiesce, cpu_hotplug;
44 SCLPEventCPI cpi;
45 /* guest's receive mask */
46 union {
47 uint32_t receive_mask_pieces[2];
48 sccb_mask_t receive_mask;
49 };
50 /* length of the receive mask */
51 uint16_t mask_length;
52 };
53
54 /* return true if any child has event pending set */
event_pending(SCLPEventFacility * ef)55 static bool event_pending(SCLPEventFacility *ef)
56 {
57 BusChild *kid;
58 SCLPEvent *event;
59 SCLPEventClass *event_class;
60
61 QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
62 event = SCLP_EVENT(kid->child);
63 event_class = SCLP_EVENT_GET_CLASS(event);
64 if (event->event_pending &&
65 event_class->get_send_mask() & ef->receive_mask) {
66 return true;
67 }
68 }
69 return false;
70 }
71
get_host_send_mask(SCLPEventFacility * ef)72 static sccb_mask_t get_host_send_mask(SCLPEventFacility *ef)
73 {
74 sccb_mask_t mask;
75 BusChild *kid;
76 SCLPEventClass *child;
77
78 mask = 0;
79
80 QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
81 DeviceState *qdev = kid->child;
82 child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev);
83 mask |= child->get_send_mask();
84 }
85 return mask;
86 }
87
get_host_receive_mask(SCLPEventFacility * ef)88 static sccb_mask_t get_host_receive_mask(SCLPEventFacility *ef)
89 {
90 sccb_mask_t mask;
91 BusChild *kid;
92 SCLPEventClass *child;
93
94 mask = 0;
95
96 QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
97 DeviceState *qdev = kid->child;
98 child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev);
99 mask |= child->get_receive_mask();
100 }
101 return mask;
102 }
103
write_event_length_check(SCCB * sccb)104 static uint16_t write_event_length_check(SCCB *sccb)
105 {
106 int slen;
107 unsigned elen = 0;
108 EventBufferHeader *event;
109 WriteEventData *wed = (WriteEventData *) sccb;
110
111 event = (EventBufferHeader *) &wed->ebh;
112 for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) {
113 elen = be16_to_cpu(event->length);
114 if (elen < sizeof(*event) || elen > slen) {
115 return SCLP_RC_EVENT_BUFFER_SYNTAX_ERROR;
116 }
117 event = (void *) event + elen;
118 }
119 if (slen) {
120 return SCLP_RC_INCONSISTENT_LENGTHS;
121 }
122 return SCLP_RC_NORMAL_COMPLETION;
123 }
124
handle_write_event_buf(SCLPEventFacility * ef,EventBufferHeader * event_buf,SCCB * sccb)125 static uint16_t handle_write_event_buf(SCLPEventFacility *ef,
126 EventBufferHeader *event_buf, SCCB *sccb)
127 {
128 uint16_t rc;
129 BusChild *kid;
130 SCLPEvent *event;
131 SCLPEventClass *ec;
132
133 rc = SCLP_RC_INVALID_FUNCTION;
134
135 QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
136 DeviceState *qdev = kid->child;
137 event = (SCLPEvent *) qdev;
138 ec = SCLP_EVENT_GET_CLASS(event);
139
140 if (ec->write_event_data &&
141 ec->can_handle_event(event_buf->type)) {
142 rc = ec->write_event_data(event, event_buf);
143 break;
144 }
145 }
146 return rc;
147 }
148
handle_sccb_write_events(SCLPEventFacility * ef,SCCB * sccb)149 static uint16_t handle_sccb_write_events(SCLPEventFacility *ef, SCCB *sccb)
150 {
151 uint16_t rc;
152 int slen;
153 unsigned elen = 0;
154 EventBufferHeader *event_buf;
155 WriteEventData *wed = (WriteEventData *) sccb;
156
157 event_buf = &wed->ebh;
158 rc = SCLP_RC_NORMAL_COMPLETION;
159
160 /* loop over all contained event buffers */
161 for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) {
162 elen = be16_to_cpu(event_buf->length);
163
164 /* in case of a previous error mark all trailing buffers
165 * as not accepted */
166 if (rc != SCLP_RC_NORMAL_COMPLETION) {
167 event_buf->flags &= ~(SCLP_EVENT_BUFFER_ACCEPTED);
168 } else {
169 rc = handle_write_event_buf(ef, event_buf, sccb);
170 }
171 event_buf = (void *) event_buf + elen;
172 }
173 return rc;
174 }
175
write_event_data(SCLPEventFacility * ef,SCCB * sccb)176 static void write_event_data(SCLPEventFacility *ef, SCCB *sccb)
177 {
178 if (sccb->h.function_code != SCLP_FC_NORMAL_WRITE) {
179 sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
180 return;
181 }
182 if (be16_to_cpu(sccb->h.length) < 8) {
183 sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
184 return;
185 }
186 /* first do a sanity check of the write events */
187 sccb->h.response_code = cpu_to_be16(write_event_length_check(sccb));
188
189 /* if no early error, then execute */
190 if (sccb->h.response_code == be16_to_cpu(SCLP_RC_NORMAL_COMPLETION)) {
191 sccb->h.response_code =
192 cpu_to_be16(handle_sccb_write_events(ef, sccb));
193 }
194 }
195
handle_sccb_read_events(SCLPEventFacility * ef,SCCB * sccb,sccb_mask_t mask)196 static uint16_t handle_sccb_read_events(SCLPEventFacility *ef, SCCB *sccb,
197 sccb_mask_t mask)
198 {
199 uint16_t rc;
200 int slen;
201 unsigned elen;
202 BusChild *kid;
203 SCLPEvent *event;
204 SCLPEventClass *ec;
205 EventBufferHeader *event_buf;
206 ReadEventData *red = (ReadEventData *) sccb;
207
208 event_buf = &red->ebh;
209 event_buf->length = 0;
210 slen = sccb_data_len(sccb);
211
212 rc = SCLP_RC_NO_EVENT_BUFFERS_STORED;
213
214 QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
215 DeviceState *qdev = kid->child;
216 event = (SCLPEvent *) qdev;
217 ec = SCLP_EVENT_GET_CLASS(event);
218
219 if (mask & ec->get_send_mask()) {
220 if (ec->read_event_data(event, event_buf, &slen)) {
221 elen = be16_to_cpu(event_buf->length);
222 event_buf = (EventBufferHeader *) ((char *)event_buf + elen);
223 rc = SCLP_RC_NORMAL_COMPLETION;
224 }
225 }
226 }
227
228 if (sccb->h.control_mask[2] & SCLP_VARIABLE_LENGTH_RESPONSE) {
229 /* architecture suggests to reset variable-length-response bit */
230 sccb->h.control_mask[2] &= ~SCLP_VARIABLE_LENGTH_RESPONSE;
231 /* with a new length value */
232 sccb->h.length = cpu_to_be16(SCCB_SIZE - slen);
233 }
234 return rc;
235 }
236
237 /* copy up to src_len bytes and fill the rest of dst with zeroes */
copy_mask(uint8_t * dst,uint8_t * src,uint16_t dst_len,uint16_t src_len)238 static void copy_mask(uint8_t *dst, uint8_t *src, uint16_t dst_len,
239 uint16_t src_len)
240 {
241 int i;
242
243 for (i = 0; i < dst_len; i++) {
244 dst[i] = i < src_len ? src[i] : 0;
245 }
246 }
247
read_event_data(SCLPEventFacility * ef,SCCB * sccb)248 static void read_event_data(SCLPEventFacility *ef, SCCB *sccb)
249 {
250 sccb_mask_t sclp_active_selection_mask;
251 sccb_mask_t sclp_cp_receive_mask;
252
253 ReadEventData *red = (ReadEventData *) sccb;
254
255 if (be16_to_cpu(sccb->h.length) != SCCB_SIZE) {
256 sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
257 return;
258 }
259
260 switch (sccb->h.function_code) {
261 case SCLP_UNCONDITIONAL_READ:
262 sccb->h.response_code = cpu_to_be16(
263 handle_sccb_read_events(ef, sccb, ef->receive_mask));
264 break;
265 case SCLP_SELECTIVE_READ:
266 /* get active selection mask */
267 sclp_cp_receive_mask = ef->receive_mask;
268
269 copy_mask((uint8_t *)&sclp_active_selection_mask, (uint8_t *)&red->mask,
270 sizeof(sclp_active_selection_mask), ef->mask_length);
271 sclp_active_selection_mask = be64_to_cpu(sclp_active_selection_mask);
272 if (!sclp_cp_receive_mask ||
273 (sclp_active_selection_mask & ~sclp_cp_receive_mask)) {
274 sccb->h.response_code =
275 cpu_to_be16(SCLP_RC_INVALID_SELECTION_MASK);
276 } else {
277 sccb->h.response_code = cpu_to_be16(
278 handle_sccb_read_events(ef, sccb, sclp_active_selection_mask));
279 }
280 break;
281 default:
282 sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
283 }
284 }
285
write_event_mask(SCLPEventFacility * ef,SCCB * sccb)286 static void write_event_mask(SCLPEventFacility *ef, SCCB *sccb)
287 {
288 WriteEventMask *we_mask = (WriteEventMask *) sccb;
289 uint16_t mask_length = be16_to_cpu(we_mask->mask_length);
290 sccb_mask_t tmp_mask;
291
292 if (!mask_length || mask_length > SCLP_EVENT_MASK_LEN_MAX) {
293 sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_MASK_LENGTH);
294 return;
295 }
296
297 /*
298 * Note: We currently only support masks up to 8 byte length;
299 * the remainder is filled up with zeroes. Older Linux
300 * kernels use a 4 byte mask length, newer ones can use both
301 * 8 or 4 depending on what is available on the host.
302 */
303
304 /* keep track of the guest's capability masks */
305 copy_mask((uint8_t *)&tmp_mask, WEM_CP_RECEIVE_MASK(we_mask, mask_length),
306 sizeof(tmp_mask), mask_length);
307 ef->receive_mask = be64_to_cpu(tmp_mask);
308
309 /* return the SCLP's capability masks to the guest */
310 tmp_mask = cpu_to_be64(get_host_receive_mask(ef));
311 copy_mask(WEM_RECEIVE_MASK(we_mask, mask_length), (uint8_t *)&tmp_mask,
312 mask_length, sizeof(tmp_mask));
313 tmp_mask = cpu_to_be64(get_host_send_mask(ef));
314 copy_mask(WEM_SEND_MASK(we_mask, mask_length), (uint8_t *)&tmp_mask,
315 mask_length, sizeof(tmp_mask));
316
317 sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_COMPLETION);
318 ef->mask_length = mask_length;
319 }
320
321 /* qemu object creation and initialization functions */
322
323 #define TYPE_SCLP_EVENTS_BUS "s390-sclp-events-bus"
324
325 static const TypeInfo sclp_events_bus_info = {
326 .name = TYPE_SCLP_EVENTS_BUS,
327 .parent = TYPE_BUS,
328 };
329
command_handler(SCLPEventFacility * ef,SCCB * sccb,uint64_t code)330 static void command_handler(SCLPEventFacility *ef, SCCB *sccb, uint64_t code)
331 {
332 switch (code & SCLP_CMD_CODE_MASK) {
333 case SCLP_CMD_READ_EVENT_DATA:
334 read_event_data(ef, sccb);
335 break;
336 case SCLP_CMD_WRITE_EVENT_DATA:
337 write_event_data(ef, sccb);
338 break;
339 case SCLP_CMD_WRITE_EVENT_MASK:
340 write_event_mask(ef, sccb);
341 break;
342 }
343 }
344
vmstate_event_facility_mask64_needed(void * opaque)345 static bool vmstate_event_facility_mask64_needed(void *opaque)
346 {
347 SCLPEventFacility *ef = opaque;
348
349 return (ef->receive_mask & 0xFFFFFFFF) != 0;
350 }
351
352 static const VMStateDescription vmstate_event_facility_mask64 = {
353 .name = "vmstate-event-facility/mask64",
354 .version_id = 0,
355 .minimum_version_id = 0,
356 .needed = vmstate_event_facility_mask64_needed,
357 .fields = (const VMStateField[]) {
358 VMSTATE_UINT32(receive_mask_pieces[RECV_MASK_LOWER], SCLPEventFacility),
359 VMSTATE_END_OF_LIST()
360 }
361 };
362
363 static const VMStateDescription vmstate_event_facility_mask_length = {
364 .name = "vmstate-event-facility/mask_length",
365 .version_id = 0,
366 .minimum_version_id = 0,
367 .fields = (const VMStateField[]) {
368 VMSTATE_UINT16(mask_length, SCLPEventFacility),
369 VMSTATE_END_OF_LIST()
370 }
371 };
372
373 static const VMStateDescription vmstate_event_facility = {
374 .name = "vmstate-event-facility",
375 .version_id = 0,
376 .minimum_version_id = 0,
377 .fields = (const VMStateField[]) {
378 VMSTATE_UINT32(receive_mask_pieces[RECV_MASK_UPPER], SCLPEventFacility),
379 VMSTATE_END_OF_LIST()
380 },
381 .subsections = (const VMStateDescription * const []) {
382 &vmstate_event_facility_mask64,
383 &vmstate_event_facility_mask_length,
384 NULL
385 }
386 };
387
init_event_facility(Object * obj)388 static void init_event_facility(Object *obj)
389 {
390 SCLPEventFacility *event_facility = EVENT_FACILITY(obj);
391 DeviceState *sdev = DEVICE(obj);
392
393 event_facility->mask_length = 4;
394
395 /* Spawn a new bus for SCLP events */
396 qbus_init(&event_facility->sbus, sizeof(event_facility->sbus),
397 TYPE_SCLP_EVENTS_BUS, sdev, NULL);
398
399 object_initialize_child(obj, TYPE_SCLP_QUIESCE,
400 &event_facility->quiesce,
401 TYPE_SCLP_QUIESCE);
402
403 object_initialize_child(obj, TYPE_SCLP_CPU_HOTPLUG,
404 &event_facility->cpu_hotplug,
405 TYPE_SCLP_CPU_HOTPLUG);
406 }
407
realize_event_facility(DeviceState * dev,Error ** errp)408 static void realize_event_facility(DeviceState *dev, Error **errp)
409 {
410 SCLPEventFacility *event_facility = EVENT_FACILITY(dev);
411
412 if (!qdev_realize(DEVICE(&event_facility->quiesce),
413 BUS(&event_facility->sbus), errp)) {
414 return;
415 }
416 if (!qdev_realize(DEVICE(&event_facility->cpu_hotplug),
417 BUS(&event_facility->sbus), errp)) {
418 qdev_unrealize(DEVICE(&event_facility->quiesce));
419 return;
420 }
421 }
422
reset_event_facility(DeviceState * dev)423 static void reset_event_facility(DeviceState *dev)
424 {
425 SCLPEventFacility *sdev = EVENT_FACILITY(dev);
426
427 sdev->receive_mask = 0;
428 }
429
init_event_facility_class(ObjectClass * klass,const void * data)430 static void init_event_facility_class(ObjectClass *klass, const void *data)
431 {
432 SysBusDeviceClass *sbdc = SYS_BUS_DEVICE_CLASS(klass);
433 DeviceClass *dc = DEVICE_CLASS(sbdc);
434 SCLPEventFacilityClass *k = EVENT_FACILITY_CLASS(dc);
435
436 dc->realize = realize_event_facility;
437 device_class_set_legacy_reset(dc, reset_event_facility);
438 dc->vmsd = &vmstate_event_facility;
439 set_bit(DEVICE_CATEGORY_MISC, dc->categories);
440 k->command_handler = command_handler;
441 k->event_pending = event_pending;
442 }
443
444 static const TypeInfo sclp_event_facility_info = {
445 .name = TYPE_SCLP_EVENT_FACILITY,
446 .parent = TYPE_SYS_BUS_DEVICE,
447 .instance_init = init_event_facility,
448 .instance_size = sizeof(SCLPEventFacility),
449 .class_init = init_event_facility_class,
450 .class_size = sizeof(SCLPEventFacilityClass),
451 };
452
event_realize(DeviceState * qdev,Error ** errp)453 static void event_realize(DeviceState *qdev, Error **errp)
454 {
455 SCLPEvent *event = SCLP_EVENT(qdev);
456 SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event);
457
458 if (child->init) {
459 int rc = child->init(event);
460 if (rc < 0) {
461 error_setg(errp, "SCLP event initialization failed.");
462 return;
463 }
464 }
465 }
466
event_class_init(ObjectClass * klass,const void * data)467 static void event_class_init(ObjectClass *klass, const void *data)
468 {
469 DeviceClass *dc = DEVICE_CLASS(klass);
470
471 dc->bus_type = TYPE_SCLP_EVENTS_BUS;
472 dc->realize = event_realize;
473 }
474
475 static const TypeInfo sclp_event_type_info = {
476 .name = TYPE_SCLP_EVENT,
477 .parent = TYPE_DEVICE,
478 .instance_size = sizeof(SCLPEvent),
479 .class_init = event_class_init,
480 .class_size = sizeof(SCLPEventClass),
481 .abstract = true,
482 };
483
register_types(void)484 static void register_types(void)
485 {
486 type_register_static(&sclp_events_bus_info);
487 type_register_static(&sclp_event_facility_info);
488 type_register_static(&sclp_event_type_info);
489 }
490
type_init(register_types)491 type_init(register_types)
492
493 BusState *sclp_get_event_facility_bus(SCLPEventFacility *ef)
494 {
495 return BUS(&ef->sbus);
496 }
497